Re: [Elecraft] Soundcard choice for K3s on Linux help needed
Isn't 'sound card' an obsolete term? In the old days, you used to buy a 'sound card' and install it in the backplane of your desktop. But nowadays, when someone says 'sound card' don't they really mean a separate box that goes between the USB ports on your computer and the transceiver's audio in and out? Musicians have been using these boxes for years. They call them 'digital interfaces'. If we're talking about one of these, then we should use the proper terminology: digital interface. But if they really are still 'cards', then I stand corrected. R, Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] Resonant vs. Non-resonant antennas
Here's a true statement: If an antenna is resonant, it radiates no better and no worse than a similar-sized antenna that isn't resonant. First, let's define what 'resonance' is. Remember how impedance Z consists of a resistive part and a reactive part? We usually write it like this: Z = 14 - j80 where Z = impedance resistance R = 14 ohms, and reactance X = 80 ohms (which in this case is capacitive because of the negative sign) 'Resonance' simply means that the reactive part is zero (0). The resistance can be any value, but if the reactance is zero, that's a resonant system. So this: 14 - j0 represents a resonant system. It turns out that whether your antenna Z = 14 - j80, or if your antenna Z = 14 - j0, the resulting radiation is the same. I'm assuming that there's probably a network somewhere in the system to match each of these impedances to 50 ohms. An antenna doesn't have to be resonant. But if it happens to be resonant, it won't radiate any better or worse than if it weren't. Resonant and non-resonant antennas can radiate equally well. You might say, "Well, I choose *not* to use an antenna matching network, so I'd rather my antenna be resonant, because that'll result in the lowest SWR." Yes, but in the case above where the antenna was resonant, the SWR is still 3.57 to 1, so you would probably want to use a matching network of some kind. That doesn't necessarily mean an antenna tuner... you could have a balun, a quarter-wave matching section, a trap, a coil, a capacitor or capacitors, a transformer, a particular length of transmission line, something like a delta feed or a gamma match, a stub, a resistor, or something else. The thing that got me thinking about this was a thread where somebody was bothered that their AX1 antenna (or whatever it's called) wasn't resonant. Or maybe you avoid some other antenna because it's 'not resonant'. Just realize that whether the AX1 is resonant (reactive part equals zero) or whether it's not, it'll radiate the same. Resonance is the magic that everyone is chasing, even though it doesn't buy you all that much. I'll always remember my dad saying, "I'll tell you how long to make your antenna: long enough to reach from where it begins to where it ends." He understood the relative unimportance of resonance. Rhombics are non-resonant antennas, but boy do they radiate beautifully. Similarly, any other antenna that's not resonant can be made to behave beautifully, sometimes by using a matching network or antenna tuner or whatever. "But I use one of those other methods you just mentioned, instead of an antenna tuner which has lots of loss." Careful, your matching device(s) could have just as much loss as plain old, properly sized capacitors and inductors. "But I hate twiddling knobs." Okay, that's fine. Do what you have to do, but just don't claim that your 'resonant' antenna is any better than my 'non-resonant' antenna. "But if the antenna's non-resonant, the SWR's probably gonna be higher, and that means more loss in the transmission line." So use open-wire line. "But if I use open-wire line, I'm going to pick up more noise." Not necessarily. "But, but,..." Al W6LX/4 P. S. It's actually a false statement that resonance always results in the lowest loss with a given transmission line. We pretended it was true so we could make our point. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] AX1 works great
I've never understood what "The antenna tuner does not tune the antenna" even means. The reason people say this might stem from the mistaken belief that the resonant half-wave dipole is somehow the best because of its length. But there's nothing about a half-wave dipole that makes it radiate any better than a wire of some other length. There are a lot of hams out there that are dead-set against using a tuner of any kind, feeling that the naked antenna must work without any assistance from the outside world. I suppose there's a kind of purist thinking behind that notion. I suppose there could also be a fear of losses in a tuner (which are usually unfounded, by the way). I have often found that more consequential losses elsewhere in the system are overlooked by the same tuner-averse hams. If a person has a fundamental problem with antenna tuners, they must also object to what the output matching network of the final amplifier in their transmitter does to bring the transmitter's output impedance to 50 ohms. Would they say, "My transmitter's output matching network doesn't tune the power transistors"? I mean, what does that even mean? Without that network, nothing would work. This mantra that we hear over and over-- 'my antenna tuner does not tune my antenna'-- doesn't say anything important. We may as well say, "My sunglasses do not tune the sun," or "My salt shaker does not tune my mashed potatoes." Is the point they're making that a capacitor down in the shack acts differently than a capacitor up at the antenna? If so, they're wrong. Al W6LX/4 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Lightning concerns: Was: K4 Remote: My QTH vs. a friend's, many miles to the north
I'm sure a major reason W8JI leaves everything connected is because it would take him about 4 hours to disconnect it all! :^) Jim, you have chosen to take the risk of leaving everything connected. Good for you; it shows your confidence in your own engineering. But surely you'll agree that it is riskier to leave all of your devices plugged in than to disconnect them all, if you knew for sure you were going to get hit tonight. That's all I'm saying. Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Lightning concerns: Was: K4 Remote: My QTH vs. a friend's, many miles to the north
Imagine that, somehow, you could know for certain that tonight you were going to get direct-hit by lightning on your antenna. In spite of all the grounding and bonding and spark-gapping and everything else you may have done, are you confident enough that you would trust it all and let the direct hit happen? Or would you disconnect everything -- you know, just in case? I suspect every last one of us would disconnect absolutely everything that we wanted to save. It's good to be prepared, but we all know that significant risk always remains no matter what we do. Al W6LX/4 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] {K3} How to run Diversity mode [long]
I ran my K3 in diversity mode during the ARRL 160 meter contest for the first time from this side of the country. It was a revelation. If you've never listened in diversity, you must do everything you can-- now that we're in the time of year that's favorable for the low bands-- to experience this for yourself. Top Band here in the Eastern Time Zone is a lot more fun that it was on the west coast. The K3 Owner's Manual describes diversity mode like this: "True diversity requires a pair of identical receivers running from a common frequency reference and using two different antennas." Where you connect your two antennas depends on whether you have the antenna tuner and transverter board options, but you should configure the transceiver to accept the dedicated receiving antenna at the AUX input because there's a bit less loss at this input. You enter Diversity mode with a long press of the SUB button. Usually, your main (transmitting) antenna is fed to one ear and the receive antenna to the other ear by setting "L-MIX-R = A b" in the K3's CONFIG menu. It also helps to set "SUB AF = BALANCE" so that you can use the SUB audio control on the front panel to make the two antennas sound equally loud in your headphones, in conjunction with adjusting the RF gain of each antenna from the front panel. I believe the best practice is something like the following: * While listening to noise adjust the RF gain controls for 'an equal amount of noise' from the two antennas * Then listen to a signal and use the SUB (Balance) control to equalize the levels and place the signal in the center of your stereo headphones Who would have thought that an antenna laying on the ground would be useful, but this year I tried a loop on ground (LoG) antenna as the 2nd antenna. The LoG was a square only 20 feet (6.1 m) per side, made of insulated wire, in contact with the ground, and fed at a corner with a 9:1 transformer wound on a binocular #73 core. This is the common LoG design that you see all over the web ( http://kk5jy.net/LoG/ ). The LoG is somewhat bi-directional for low angles of arrival, so I oriented it northeast-southwest. I got the best results by: 1/ Using an antenna tuner to better match the LoG to the 50-ohm input of the K3. A LoG has very high loss, so everything you can do to conserve its signal power helps. I noticed an S-unit of LoG receive improvement when using the tuner. 2/ Turn the preamp on for the LoG, but the attenuator on for your main antenna. 3/ Route the main ant to your left ear and the LoG to your right, as discussed earlier. 4/ Because my LoG was directly under the transmit antenna, and even though I possibly could have done without one, I was more comfortable with a PIN diode switch to protect the AUX input (which is where the receive ant enters the K3). I built a circuit that takes the KEY OUT of the K3 and switches a bias voltage to the PIN switch: +12 V on receive and -12 V on transmit. This switch has a measured isolation of > 60 dB... good enough for transmitting at 100 W and probably much more. However, this might have been overkill and a simple diode limiter probably works just as well. Using the RF gain and Balance controls, you can center a signal in your headphones as discussed earlier. Pretty soon you'll have a soundstage between your ears where signals seem to float from left to right and back again as fading and polarization occur. It's as if your head is inside the band. It's a very powerful psychoacoustic experience that gives you a visceral feel for what propagation is doing. Instead of fading in and out, signals move from left to right and back again, sometimes slowly, sometimes abruptly, always randomly. My main ant being a horizontal dipole, I was pleased that when a signal would fade *out* on the main, it tended to fade *in* on the LoG, and vice-versa. The end effect of this is that you largely mitigate QSB. Signals stubbornly hang in as the band does its fading thing. Since the contest, I've tried the LoG on 80 and 40 and it works even better on those bands. Since your main ant's RF gain is cranked way down to match the LoG's output, everything sounds quieter. I found myself wondering why my noise level was so low. But don't worry, you'll still have enough sensitivity. The noise floor is so low that you feel as though you can copy signals down to negative infinity. The effect is addicting! If your K3 or K4 has a subreceiver, I urge you to try diversity mode. I think you'll be delighted at what you hear. Al W6LX/4 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] Measurements of a KAT500
Now and then, someone accuses the KAT500 of disturbing their impedance match even when it is bypassed. I wanted to see just how much residual mismatch the KAT500 has when it's in bypass mode, so I made a couple of measurements today. I took measurements at 3.6, 7.1 and 28.3 MHz; in other words, on 80, 40 and 10 meters. I suspected that 10 meters would be close to a worst-case scenario, which is why I included it in this test. In Step 1, I connected my dummy load to the VNA and measured its impedance on the three frequencies. In Step 2, I connected the dummy load to the ANT #3 output of the KAT500 in bypass mode and measured the input impedance of the tuner. Let us begin at 10 meters and get the bad news over with. The dummy load by itself, at 28.3 MHz, measured: 48.954 - j*0.032 Ω It's hard to digest this, so let's convert that impedance to SWR: 1.021. Now, the same dummy load through the bypassed KAT500 measured: 46.866 + j*1.498 Ω, or in terms of SWR: 1.074. Are you alarmed? Let's break this down a bit to understand if this is really, really bad, or just kinda bad. In an ideal world, when you put a KAT500 into bypass it should 'disappear'. It shouldn't change anything. It should feel as if the tuner wasn't there and you were directly connected to the dummy load or whatever is on the output of the tuner. And you should measure the same exact impedance as when the tuner really was out of the picture. But in reality, this is impossible. Even when bypassed, a device like an antenna tuner adds length -- the distance between the input and output connectors-- and this length, like all conductors, has a little bit of inductance. The tuner is also going to add stray capacitance. Imagine shrinking down to the size of an electron and entering the tuner through the coax. The first thing you see is a coax connector, followed by a cable, a relay, a circuit board, another thingy maybe, and eventually you emerge from the tuner at another rear panel coax connector. By traversing this path, you were subjected to the stray capacitance and inductance of all the stuff you touched or passed by. By virtue of being in the real world, the tuner doesn't disappear but in fact adds a measurable perturbation to an otherwise pristine path. How much did my KAT500 add in this real and imperfect world? In order to bump the dummy load's impedance to the new value I measured, the KAT500 had to add the following: 24.2 pF of stray capacitance -- a totally believeable value, and 64.1 nH of inductance from the path -- again, a value in line with reality. In case you're still laboring under a pretty good shock right now, don't be too scandalized. Perhaps it's helpful to recall this: First, you've heard of LMR-400 coax, right? Well, LMR-400 coax has a capacitance of 24 pF per foot. That's right, just 1 foot of this pretty good coax has 24 pF (actually 23.922 pF, according to renowned transmission line guru AC6LA). Second, that same piece of coax has 61.5 nH of inductance. Holy smokes, those numbers are darned close to the KAT500's!! The KAT500, when all is said and done, looks pretty much like a short 1-foot section of very good coax when it is bypassed, with a tiny bit of mismatch thrown in for good measure. In addition, I wish I could post a screenshot of my Smith Chart with the before and after impedance values plotted on it. The distance between the two points is far less than 1/100 of the diameter of the Smith chart. The two points are virtually on top of each other. It's only because of the resolution of the test equipment that we can even see the difference between 1.021 and 1.074. (On 80 and 40 meters the difference is literally two-tenths of an ohm-- not even worth mentioning here.) I hope that this put a new perspective on something that we see here on the reflector rather often. Regards, Al W6LX/4 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] [K3] Spinning VFO B very quickly shuts down K3
Here's a problem that I'm curious if anyone else can reproduce it. I'm running K3 firmware 5.66. If I spin the VFO B knob *really* fast in either direction, the radio shuts down. (On rare occasions it will hang and require power supply shutdown to turn it off.) I highly doubt it, but just in case: can anybody else reproduce this problem? Only if you can reproduce it, please email me privately, to keep the list traffic low. If I don't hear from anyone, I'll know that it's a Me problem only. Thanks, Al W6LX/4 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] [OT] Wayne Burdick wins 1st annual Kitchen Homebrew Challenge
Wayne Burdick, N6KR, has taken the gold medal at the 1st annual Kitchen Homebrew Challenge held over the weekend. The contest challenged engineers to construct a QRP transmitter using just three transistors and whatever else they could find in their kitchens. Although the designers were allotted 12 hours to complete the task, Burdick finished in half an hour. "I used the remaining time to try and contact some stations with my transmitter and I came pretty close to Working All Continents, thanks to a fantastic and unexpected 10-meter opening!", he exclaimed. Thirty other engineers from virtually every other manufacturer of amateur radio equipment entered the contest. A contestant from a large corporation in Japan known for its fine transceivers placed second when the judges deemed his transmitter closest to actually working, although it did not put out any power and kept blowing fuses. Burdick needed only two of the 2N transistors he was given to achieve an output power of 1/4 Watt. "I know 2Ns like the back of my hand," he explained. "I felt sorry for one of the other guys, a younger engineer, who was begging the judges for a datasheet on that device. I guess he'd never used a small transistor with leads before and had no idea which were the base, emitter, and collector." "For my capacitors, I used entire boxes of aluminum foil and parchment paper, and for the inductors, I used the heating element from my toaster," he said. "Once I had the oscillator done, it was all downhill from there." "I thought of the heating coil idea, too, but I couldn't remember the formula for the inductance of a round inductor," said another contestant who wished to remain anonymous. One of the other competitors implied that Burdick had an unfair advantage. "Isn't he that QRP backpacking guy? Here I was, trying to figure out how to steal the A-to-D converter in my coffee maker. I ripped apart the refrigerator motor for the wire and I tore my undercabinet lighting out so I could use the LEDs to display an FFT of my signal, but if I had known I could just make a simple oscillator and amplifier in an empty can of creamed corn with pill bottle caps for knobs, I might have finished in 30 minutes, too." "I really made a mess of my kitchen and my wife is going to kill me," he lamented. One of the major obstacles in this competition is how to come up with a supply of power. A player from the US attempted to use the power supply in his microwave oven. "Eeesh, you shouldn't use the 1200 Volt power supply in the microwave!", warned Mr. Burdick. Mr. Burdick explained his own rationale for a source of power: "I was going to use an entire sack of potatoes and lemon juice to make a battery, but in the end I just collected batteries from my kitchen timer, cordless phone, and the emergency flashlight I keep in a drawer in case of power outages. I really had more than enough power. This was a relief since I had wanted to grill those potatoes for the Labor Day barbecue." He summed up his experience by saying, "Simpler is better." Burdick, a legend among low-power portable enthusiasts, has used homebrew equipment to make contacts while walking, swimming, and sleeping. He is co-founder of Elecraft LLC of Watsonville, CA. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] A dumb question about lightning
Hi, Everybody, I greatly apologize for escalating the list traffic with my question on lightning. I merely wanted to get your thoughts on disconnecting equipment in addition to grounding and bonding. And the overwhelming consensus-- in both public and private responses-- is that yes, in fact, most people physically disconnect, rather than relying 100% on grounding and bonding to protect their equipment. So I'm going to continue to do so, accepting this practice as necessary in the state where I now live. Keep on reading the books, installing proper grounding, follow the law, and follow good practice. And good luck avoiding a direct hit! Regards, Al W6LX/4 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] [OT] A dumb question about lightning
Please don't laugh at me; I'm a transplant from a region of the country with essentially no lightning to a region where you have to worry about it quite a bit. We had a doozy of a storm last night, with lots of lightning overhead. I felt like a sitting duck, even though I had grounded both sides of the balanced feedline of the antenna, switched the antenna switch to the middle (grounded) position, and even disconnected the coax leading to the K3's rear-panel antenna port. Whenever lightning happens, I always wonder if it really is in fact better to ground everything. Because, doesn't that essentially make a lightning rod of the antenna? If I simply disconnected the antenna and left it floating, wouldn't it be less likely to attract a lightning bolt? I'm of the belief that it's better to try to avoid a direct hit than to attract one and trust your grounding system to do its thing. I'm of the belief that no grounding system is perfectly effective. Al W6LX/4 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Field Day Operation
Wow. I can't even imagine working 1532 contacts in 24 hours. If, in fact, you stayed awake for 24 hours straight, that would have meant you maintained a 64 Q per hour rate for the duration. That's an incredible run for *any* contest. Congratulations, sir! Yeah, I let my frustration out on the air when I probably shouldn't have... but the guy matched me rude-for-rude, that's for sure, and I've already explained that he was not a newbie. Not only is it against the rules to fail to identify, it's actually detrimental to him because he makes people wait a long time to hear his call sign, and that undoubtedly leads to lost contacts as people give up waiting and leave. He (and the others) shoulda known better. The only reason I continue to operate SSB on Field Day is because my two sons operate with me and, since they don't know CW, this allows them to participate with me, which so far has made it worth putting up with the circumstances I complain about. We again used the K2... the all-time, world's finest Field Day rig. Absolutely, flawlessly wonderful. Al W6LX >>>But looking back some years I operated either 1E or >>>1D and single-handedly worked 1040 Qs in 2001, 1357 in 2004, 1532 in 2005, >>>1093 >>>in 2007 and slowed down to 1075 in 2009. All on SSB and 100W. With a >>>regular >>>logging program and no voice recording. >>>Wes N7WS __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K4 Rx is awesome...
> I can hear many many stations but hardly any of them can hear me. The most likely reason for this is operator inexperience, which is a perennial problem on Field Day. It's great that lots of people who don't usually get on the air, get on the air... but the side effect of this is a lot of really poor operating habits. The biggest problem this year, in my opinion, was not identifying at the end of each contact. Many ops who were running on a frequency simply would acknowledge receipt of the exchange, then just stop transmitting and listen for the next caller. Here's an example: W4---: CQ Field Day, this is W4---. W3--: This is W3--. W4---: W3--, I'm 2A Georgia. W3--: Thanks, I'm 4A Western Pennsylvania. W4---: Got your 4A Western Pennsylvania. Good luck in Field Day! See the problem? This would sometimes continue for 5, 6, or 7 contacts, with the W4 never sending his own call. So, be me for a minute: there I am, waiting to call the W4, except I don't know he's a W4 because he hasn't said so, and neither has anybody else. After the first 20 or 30 times this happened, I stopped waiting around for these stations to finally identify themselves. Once, when this happened for about 6 contacts while I waited around to work a strong station in Georgia who refused to identify, I became frustrated and transmitted, "Hey, Old Man, you need to ID after each contact!" The guy immediately came back, "Let me tell you, young man, that we're all Extra class operators here who finish in the Top 10 every year, so you're not going to lecture me on how I should operate!" I went to CW after this and found the operating to be a lot better. I still heard the problem I just described, but not as frequently as on phone. Another common malpractice was people who were calling CQ, and who would receive a response to their CQ, but then would tell the caller to send his exchange first. This isn't the way you do it. The CQing station always sends its exchange first, then turns it over to the calling station, so that the CQing station can acknowledge receipt, identify, and stand by for another caller. I feel like we go over this after every Field Day, and nothing has ever changed. I feel like Get Off My Lawn Guy right now. If you're in a club that's planning a Field Day operation, you need to take the April or May club meeting and help people practice the Field Day exchange protocol with mock QSOs. It's getting really bad on the phone bands during Field Day. (I didn't mean to subtract from your enjoyment of your new K4. I hope it turns out to be a great rig for you for many years.) Regards, Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Elecraft CW Net Report
Kevin's perseverance is astonishing. Week after week, suffering through poor conditions. He never seems to catch a break. So here is THE KD5ONS CW NET REPORT I HOPE TO READ BEFORE I DIE. "Signals were fantastic. There was no hint of noise nor QSB. At one point, I laid the headphones down and could still copy everyone. We had 91 checkins, including some DX. We all reduced our power to 100 mW. A fox nestled at my feet to listen. A bald eagle landed on the window sill while I called the net. The birds were even chirping CW. It was a night for the ages. See you all next week." Al W6LX/4 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Where to put the wattmeter
Yes, if you're willing to do the math in your head, or can set up your fancy wattmeter to do the math for you, this'll work. But the main reason why I don't like the idea of putting the wattmeter (or sensor, actually) in a non-50-ohm location is the additional uncertainty due to the mismatch(es). In the original poster's situation, there would be a mismatch at the interface between the input of the sensor and the KAT-500's output, and another mismatch at the interface between the output of the sensor and the input of the feedline. How large would the additional uncertainty be? It depends, but assuming that the wattmeter sensor has a (very good) match of 1.2:1, and the antenna has 4:1 -- which is not out of the question for many antennas-- the additional uncertainty is about ±1.0 dB. This means that if the actual forward power were 500 W, the wattmeter may read (after doing the math mentioned above) as much as 1 dB lower, which is 397 W, or 1 dB higher, which is 630 W. That's a whole heck-of-a-lot of error there that many hams wouldn't tolerate. Nobody had raised the issue of uncertainty and that's why I wanted to point it out. Y'all can have the last word on this. R, W6LX/4 I'm fairly sure that (forward power) - (reverse power) gives the correct nett output power, before cable and antenna losses. I'd need to review the maths to be sure. Most reflected power ends up re-re-reflected, as additional forward power. A high SWR will giver reflected power almost as high as forward power. -- David Wooley __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3 & K3S Options Last Time Buy Update (12/02/2022)
The most likely near future, which Elecraft has (have?) apparently chosen, could be the constant grumbling we will all make for years to come as we sit and stare at our K3s with various dead boards. Flex, Yaesu and Icom are all rooting for this status quo to continue. I'd like to suggest a different future. For decades, China has reverse engineered practically everything and then sold it for half of what it costs us to make it. I'm pretty sure you could take any K3 circuit board to China and have a working prototype in like 24 hours. But it would take an entrepreneur among us to make that happen. Al W6LX/4 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] RF in the shack ≠ RF overload
Here's a statement: "RF in the shack" does not equal "simple RF overload". Let me define my terms. "RF in the shack", which many people have experienced when using "unbalanced" antennas like verticals, off-center fed wires, and others, is caused by radiation from the outside shield of the coax, or by unequal currents on either side of a balanced transmission line. As you know, this causes everything from interfering with household devices to RF burns. Many folks have cured this kind of problem with various ferrite chokes and grounding. But there's another kind of interference: that caused by "simple RF overload", which occurs when your beautifully balanced antenna, with lots of ferrite all over the place, judicious routing of the feedline, and good grounding, is radiating so well that the RF field around the antenna-- and thus, inside your home-- is very high. Paradoxically, this is what you want to happen; your highly efficient antenna system is turning your RF power into a nice, strong radiated field. So it's important to understand the difference between these two mechanisms. Maybe a story will help you further understand the distinction I'm making. I attended a high school not far from 50 kW radio station KRLA. KRLA used to get into everything. It was so loud on a crystal radio that you could hear it easily with the earphones laying on the benchtop. If you left an oscilloscope probe disconnected the scope would show an enormous 10V peak-to-peak signal on the screen. Was KRLA guilty of RF on its feedline, putting "RF in the shack" into our electronics lab? Would ferrites and additional grounding at KRLA's antenna have improved anything? No, because it was a case of "simple RF overload"... caused by a very strong, very close transmitter. KRLA was doing exactly what it should have done: put a bodaciously loud signal everywhere. We just happened to be 'in the way' of that signal. This is what can happen when you have a perfectly good and RFI-proofed antenna system. The radiated signal is simply too strong for various electronics in your house to handle. And, as you can imagine, running the legal limit makes the problem worse. This is what I was trying to communicate in a previous post. I had essentially asked, "Given that your properly functioning antenna is putting a bodaciously loud signal everywhere, why are some devices immune to the signal, and yet others fall apart? Why does one ham's garage door opener go crazy when he transmits, but another ham's is unaffected?" That's what I was wondering. A number of respondents to my other post told me that yes, in fact, there are devices that act naughtily when they operate high power, but at least as many said that they've *never* had any such problems. Isn't that interesting? Is it just luck? I've purchased faulty devices while they lucked in and purchased all good ones? The engineer in me hates this arbitrarity and drives me to understand why. What are the unaffected hams doing differently than the rest of us, if anything, to prevent not "RF in the shack", but the dreaded Simple RF Overload? To keep the reflector quiet, maybe you can email me privately and I can post a summary of comments later on. Or not, if you're sick of the topic. Thanks! Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] Fluorescent RFI solved
I hope this helps anybody facing the same issue. The fluorescent lights in my basement make horrible RFI noise, especially on 40 m but really affecting all bands. They raise the noise floor by about 16 dB on 40. I discovered this during Field Day *last* year when I set up in the back yard. They use these electronic ballasts that put out perfect square waves -- that's the source of the noise. The entire bulb and wiring act as a radiator, and there's about 8 feet of wiring in each fixture. I did some research on the web and found a guy with the same lights who had disassembled every one of his fixtures to install filter capacitors, and I considered following his procedure but decided it was waaay too much work to undertake, so I've lived with the problem for a year-and-a-half. Anyway, at Menard's the other day I noticed these Feit LED replacements for the 4-foot fluorescent tubes. These have existed for years now, but these bulbs were different. They said "ballast bypass" on the box, and upon closer reading I learned that to use these as replacements you have to re-wire your fixtures by taking the ballast out of the circuit. (They're also called "direct wire" bulbs.) The hot and neutral go directly to the bulbs without anything else in between, just like incandescents used to be. Well, this intrigued me because I wondered if, with the ballast out of the loop, it would quiet things down. So I bought a few of them-- they're not too costly-- and re-wired one of my 4 fixtures and with the lights on I noticed that the noise floor had actually lowered perceptibly (and on the panadapter). I immediately went back to buy the 14 more bulbs I needed and now I can't even tell that the lights are on... there's no RF noise! So these LEDs are the answer to the evil electronic ballasts that I don't know how they got past the FCC. When purchasing LED bulbs one always risks incurring more noise from the LED circuitry itself, but I've always had pretty good experience with Feit and this was no exception. I can't speak for other brands. R, Al W6LX/4 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Running high power
Thank you for all your responses. I did not mean my question to solicit the thousands of ways of solving this problem, but merely a poll of hams' experiences running high power. Based on all of the private and public responses I received, it's about 50% who've had problems with consumer equipment and high power. If the problems are caused by simple RF overload of the piece of equipment, I've never understood why balanced or unbalanced antenna systems make any difference. If your 1500 W signal induces a large interferer on the circuitry of your internet modem or garage door opener, the device has no idea whether you're using a Yagi or a dipole or a vertical or whatever. It's just being overloaded because it's in the near field of the antenna and has very poor rejection and filtering. You could have the best-balanced antenna system in the world and still get into a poorly-shielded modem, couldn't you? The interference isn't coming in through the wires, it's coming in through the air! I tend to resonate with K9YC's assertion that there are a whole lot of devices out there that are designed badly, susceptible to the slightest overload. When I look at my own situation I notice that I have tons of devices that were completely unaffected. My telephones, lights, garage doors, overhead fans, smart thermostat, and many others-- all of which have RF circuitry to one degree or another-- were never bothered. Taking the FM radio in the kitchen as an example, you could make the argument that since its whole purpose in life is to receive weak signals, that it's particularly vulnerable to a large HF signal. But not a single person mentioned that they've ever heard themselves coming through their FM radio. I must have the only cheap table radio in America! Anyway, I envy those of you who told me, "I haven't the slightest idea what you're talking about." R, Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] Running high power
I'm really curious to ask those on this list who run high power: Do you find that you get into all kinds of devices around the house? I ran the KPA-500 in an extended manner for really the first time during the Phone SS and immediately: 1/ interfered with FM broadcast radio. 2/ caused the internet to drop out every time I keyed up on the lower bands. Am I the only one? Those of you who run high power all the time... how do you deal with these annoyances? Al W6LX/4 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Yamaha Headphones
>>> An electret mic has much better fidelity than an inexpensive dynamic mic, >>> so the CM500 is probably a better choice. Is that really true? If you looked inside all of your local AM broadcast stations, all you'd see are dynamic microphones. I'm not sure why most headsets have electret mics. Maybe it's because they have a higher output which lessens the need for a lot of preamplification? I don't know. Al W6LX/4 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] QRP and Contesting
This issue is a kind of double-edged sword that cuts not only newbies with bad fists, but Big Guns with fists that are, well, *too* good. I noticed this opposite phenomenon as soon as CW SS got started. It seemed that the average CW speed was way up this year. (I hadn't operated the SS in a couple of years, so this trend may have started a couple of years ago and I just now have experienced it.) My CW skill is decent, but even I got into hot water when copying some exchanges: Was that 378A? Or 377U? Asking for a repeat didn't always help, because at 45 WPM slight multipath distortions in the ionosphere start to mess with high-speed CW. Not a single op slowed down for me, even if I had to ask for multiple repeats. Then there's this: When you think about it, there's no incentive to help someone like me copy correctly. After all, if I copy incorrectly, I'm the one who gets penalized, not him. By asking for a repeat, all I'm doing (in his mind) is slowing him down on his run frequency. And probably ticking him off? I mean, 30 WPM with no repeats is actually faster than 40 WPM with some repeats. You may say, "Well, Al, you're a lid for entering a contest if you're unable to copy quickly enough to participate." Maybe so, but the obstinacy of operating at 40+ WPM no matter what shows a colossal disdain for the Little Pistols who are the bread and butter of the elite. In two weeks we'll get to hear the Phone SS equivalent of this obstinacy: absolutely nasty, overdriven, groaty, fingernails-on-a-chalkboard, bad audio. How lovely. R, Al W6LX/4 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3S Noise Reduction
Good advice from Chuck and Bob below. The thing to remember is that the noise reduction isn't just an on/off button. There are 32 levels of noise reduction to choose from. Some of the levels add just a touch of NR while others almost destroy the signal, adding artifacts and other things in the process. So you gotta play with it a little bit to suit your taste. You'll find a setting that pleases you. Here's what Wayne said about the settings when he released firmware rev. 3.30 on 2 September 2009: __ "* MORE NR (NOISE REDUCTION) SETTINGS: There are now 32 NR settings. F1-x to F4-x originally appeared in firmware revision 3.27, and are recommended for most applications. F5-x to F8-x are the same as F1-x to F4-x from firmware revision 3.25. They provide a varying mix between processed (“wet”) and unprocessed (“dry”) audio. When x is 1, the mix is mostly "dry"; when x is 4, it's 100% "wet". A small letter “m” (e.g. "NR m F5-1") reminds you that "mixed" settings are in use. Note 1: When you’re experimenting with different NR ADJ settings, allow 1 to 3 seconds for the DSP to fully adapt to present signal conditions. Note 2: F5-x and higher NR settings may alter the amplitude of single-tone (CW) signals somewhat, depending on the pitch. Voice signals are less affected." __ R, Al W6LX/4 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] [K3] KIO3 failure mode
Ah, lightning. Whoever performs an analysis of the KIO3 failure mode after being struck by lightning might have what's necessary for a very lucrative business. Actually, I'm surprised that the board hasn't already been reverse engineered in China, enabling an aftermarket for KIO3 replacements. I bet everybody on this reflector living east of the Rockies would buy two of them in anticipation of future thunderstorms. Al W6LX/4 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K2 versus K3 specs
> The K2 is somewhat of a spiritual event. There are many > who are very attached to their K2's... because we built them, > got familiar with them, used them in memorable situations, > and became fondly attached. So true, Robert! My K2 got soaked in a giant rainstorm in Virginia a few Field Days ago in one of those fine, fulminating downpours-at-midnight with lightning and general spookiness. We had to run for our lives into the truck and forgot all about the poor rig sitting stoically on the picnic table. In the morning, the damage was assessed: transistors standing in pools; resistors barely keeping their chins above water. And no power-up. We tried everything to dry it out. Leaving it in the sun on the dash of the truck. Q-Tips. But as FD approached it was clear that it wasn't going to dry in time. My sons and I were way bummed out and I felt very stupid. So how's this for good luck: it so happened that another ham was in the same campground, noticed us, and *brought over his wife's blow dryer* to help us out. We got the K2 on the air just in time, but when I went to invite that ham to operate with us later on, he'd already left. I'll never forget what he did for us. I'll bet that's the closest anyone on this reflector has come to killing his K2... but K2's evidently Die Hard. This year the K2 again showed no ill effects from its near-drowning and performed flawlessly and continues to amaze me. It's simple enough to operate and no simpler, making understanding and using it within the reach of even my youngest son. We and our K2 have been through far too much together to part ways. K2 forever, baby. Al W6LX/4 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] [OT] Note from a skeptic
A couple of people have asked me for more detail. The failure mode was interesting. The battery is, in fact, charged. The no-load terminal voltage is 13.5 V. However, as soon as you put a load on it -- even just 1 mA current draw... actually, even pressing your fingers onto the terminals to draw a few microamps-- the voltage starts dropping, eventually reaching zero at some current. Somewhere inside that pretty ABS case is a fully-charged LiFePO4 imprisoned by the very circuit that is supposed to keep it healthy and available. I think that's what makes this so tragic. Al W6LX/4 On Wednesday, June 29, 2022 at 04:22:38 PM EDT, Richard Hill wrote: There is a good chance your battery came with, or should have, advice to charge the battery every six months or less to keep it alive. I know we hate to read instructions...but in this case it is an expensive avoidance. Had my education. Nu6t On Wed, Jun 29, 2022, 1:15 PM Drew AF2Z wrote: > Batteries have their place but in general I hate the things. Anyone who > has had to maintain a battery systems does. Now I have them scattered > all around the house in various states of charge or dying... > > Oh sure, they're great for one or two portable devices that you use > frequently. But here I am again, back in the battery maintenance role > and not even getting paid for it... Yeah, in general I hate batteries. > Having a battery-based energy distribution system is just plain nuts. > > 73, > Drew > AF2Z > > > > On 06/29/22 14:57, Al Lorona wrote: > > Late last week, I pulled my two-year-old LiFePO4 battery out for Field > Day prep and found that it had failed. Efforts to reset the battery > management system didn't succeed. I got to use this battery on exactly two > Field Days, which means it cost me almost $200 per Field Day! Sad, very, > very sad. > > > > The dealer is honoring the warranty and a new battery is on the way, but > I've become a LiFePO4 skeptic. I don't care for battery management system > electronics that can fail where I can't get to them: sealed up inside the > battery case. > > > > If stuff like this starts happening to everybody's electric car... oh > boy, look out! > > > > > > Al W6LX/4 > > > > > > > > __ > > Elecraft mailing list > > Home: http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/mmfaq.htm > > Post: mailto:Elecraft@mailman.qth.net > > > > This list hosted by: http://www.qsl.net > > Please help support this email list: http://www.qsl.net/donate.html > > Message delivered to pu...@af2z.net > > > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to nu6t.r...@gmail.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to alor...@sbcglobal.net __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] [OT] Note from a skeptic
Late last week, I pulled my two-year-old LiFePO4 battery out for Field Day prep and found that it had failed. Efforts to reset the battery management system didn't succeed. I got to use this battery on exactly two Field Days, which means it cost me almost $200 per Field Day! Sad, very, very sad. The dealer is honoring the warranty and a new battery is on the way, but I've become a LiFePO4 skeptic. I don't care for battery management system electronics that can fail where I can't get to them: sealed up inside the battery case. If stuff like this starts happening to everybody's electric car... oh boy, look out! Al W6LX/4 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] P3 as a phase noise measurement tool
According to Al, N1AL, "The effective bandwidth of the P3 is approximately one pixel on the display, which is SPAN/468. So, for example, if the span is 47 kHz, the effective bandwidth is about 100 Hz." To "convert" or "correct" to a 1 Hz bandwidth, use the formula: BW_correction_factor = 10 * log(P3_effective_BW) For instance, to "convert" a 100 Hz effective P3 bandwidth to 1 Hz, the factor would be 20 dB. So, if you measured a noise level of -80 dBm on the P3 whose effective bandwidth were 100 Hz, that would really be -100 dBm in a 1 Hz bandwidth. Al W6LX/4 On Tuesday, June 7, 2022, 11:06:05 AM EDT, Dave (NK7Z) wrote: Hi, I am contemplating practicing some phase noise measurements using a P3. If I correctly understand the measurement, (which I may not), I should express the result, using db down from peak, so many Hz away from peak, using a 1 Hz width. First question; is the above correct? Second question; (amusing Q1 is correct), what is the pixel width of the P3, and can I just divide that width by total frequency spread shown on the P3, and assume that number I get is correct for width per pixel in Hz? Third question, (assuming Q2 is correct), once I get a number from question 2, can I then just divide that result by X, where X is selected to bring the width of measurement to 1 Hz? Thanks in advance for any help in this... -- 73, and thanks, Dave (NK7Z) https://www.nk7z.net ARRL Volunteer Examiner ARRL Technical Specialist, RFI ARRL Asst. Director, NW Division, Technical Resources __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to alor...@sbcglobal.net __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] [OT] Specs
Several weeks ago, someone here recommended listening to a recent interview with receiver test guru Rob Sherwood. In it, the interviewer pressed Rob for a radio recommendation. At first he resisted but eventually gave three transceivers that he said "anybody would be very happy with". But when he compared them, instead of pointing to specs like dynamic range, sensitivity, receiver noise, &c., his deciding factors were interesting. Speaking about one radio model, he said, "It's a good receiver, but it's got a really loud relay inside when you send CW." About a model from a different manufacturer, he said, "Great radio, but the spectrum display makes me dizzy." About another: "The speech processor doesn't work that well." And this went on. In other words, just like the rest of us, he believes there are lots of other factors that make or break a radio, many more than mere numbers or specs. (At one point Rob said, "I think I've created a monster," referring to The List.) This is why I have written here in the past that you have to get a radio into your hands before deciding whether it's any good; making your decision on the numbers alone doesn't give you any real idea how the radio performs. Don't write off a new radio just because it's in ninth place (or whatever) on The List. Don't be surprised if you don't like one of the "top radios" on The List. Be open to liking a radio or manufacturer farther down The List. That's what Rob Sherwood does. R, Al W6LX/4 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] [OT] The dreaded 400 Hz hump
Have you studied how SSB signals look on your panadapter? I believe about 90% of all phone signals have a very pronounced peak at about 400 or 500 Hz. This peak is sometimes 10 dB (or more) higher than the rest of the bandwidth. This is wasted power and, to my ear, makes signals sound muddier. On the other hand, every once in a while you'll see a signal that has a more or less flat frequency response, without any huge peaks. Sometimes, a signal will actually have slightly *more* power in the higher frequencies, say, 2000 Hz and higher. I've noticed that these signals have much more articulation and punch. But these signals are all too scarce. It's pretty well known that the aging population of hams collectively suffers from a high frequency hearing loss. It seems to me that this is even more reason to carefully shape your frequency response and cut the dreaded 400 Hz hump. R, Al W6LX/4 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K4HD Executive Summary Request -- strong signal performance
This page: https://ham.stackexchange.com/questions/1124/what-does-a-noise-blanker-really-do-and-what-are-the-side-effects contains a pretty good synopsis of why noise blankers mess up on strong signals. Al W6LX/4 >In the end all I learned was that NB >levels were mostly unpredictable in how they produced signal artifacts, >except that they almost always did. > >Vic, W9RGB __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] [OT] Loss in window line [OPINION] [LONG]
Whenever somebody mentions "window line" here, one of the first objections raised is that "when it gets wet, it has very high loss". The landmark paper cited is by Wes Stewart, N7WS, which can be found here: https://www.sadxa.org/n7ws/Ladder_Line.pdf . I'm not trying to discredit that paper in any way, but I'd like to point out two things to keep in mind the next time you hear someone completely and summarily dismiss window line on the grounds that it has "high loss when wet", and citing that paper: 1. You should note that Wes took measurements at 50 MHz. Window line is rarely used at that frequency, and anyway the loss has to be extrapolated back down to the HF region. For instance, if wet window line has a loss of 5.2 dB at 50 MHz, the loss at 10 MHz is only 2.3 dB and at 3.5 MHz is 1.4 dB. (See the paper for the equation to extrapolate to another frequency.) 1.4 dB sounds a heck of a lot better than 5.2, and is on par with 100 feet of the best coax you can buy. (We are talking only about matched line loss here, and ignoring additional loss due to SWR.) So that's the first thing. 2. Wes's method involved the now legendary use of a "wetting agent" (I assume soap of some kind) added to the water he sprayed onto his 12-foot sample of transmission line to simulate rainy conditions on weathered line. To be fair, Wes himself cautioned that this probably created a worst-case scenario but judging from other references on the web this wetting agent has been blamed for excessively inflating the loss to the point of questioning the relevance of the experiment. DJ0IP and G3TXQ have both claimed that (see http://www.karinya.net/g3txq/wet_ll/ ). In G3TXQ's case, he was able to replicate Wes's results by using "a few drops of washing-up liquid" but he states, "It is not clear whether the high losses associated with using the wetting agent were due to the more complete wetting of the line or to some electrical properties of the agent. Nor is it clear how well this test represents conditions that will be experienced in the 'real world'." What's happening to the line when it gets wet, and why should it's characteristics change at all? To answer this, understand that in balanced line, the energy is carried in the field between the conductors. Window line has mostly polyethylene (PE) between the wires which has a dielectric constant of 2.3, as opposed to air's which is 1.0. Spraying water-- which has a dielectric constant of 80-- onto PE insulation changes the material properties between the conductors and, thus, the capacitance. As capacitance changes, so does everything else: velocity factor, impedance, and loss. One thing saving us from a catastrophic change in properties is that water tends to bead up and remain as droplets, and droplets don't like to stay connected with other droplets. So if you looked at a path perpendicularly across the surface of the line, you'd see individual, sparse drops rather than a continuous film of water. I couldn't find the dielectric constant of soapy water anywhere on the web -- but let's assume that the number is close to that of pure water: 80. If you could somehow give the field a *continuous* path of water from one side to the other on the window line, you'd have significantly altered the dielectric constant of the PE; you'd essentially have added a new "path" in "parallel" with the PE with a dielectric constant some 35 times higher. Although it would be a very thin layer, it nonetheless could have a significant effect, as N7WS and G3TXQ have shown. We also have an important data point from Bob, K4TAX, showing that the loss of Bob's window line is pretty much unaffected by rain, although the electrical length does change. I'll address why this might be later on, but the point is that this is credible, measured data. Why are these data so different? I did discover that soapy water's pH is above 10 -- possibly as high as 12-- indicating that there are abundant salts present, probably sodium and/or potassium. These dissolved salts strongly ionize the water, greatly increasing its conductivity (and perhaps changing its other electromagnetic characteristics). On the other hand, rain water is essentially pure, much closer to distilled water, with relatively few contaminants capable of being ionized. (See https://www.waterboards.ca.gov/water_issues/programs/swamp/docs/cwt/guidance/3130en.pdf). Having said all of this, when you study the G3TXQ paper I mentioned earlier, there's a glaring data point: Steve measured nearly constant, high loss, using soapy water, *from 7 through 30 MHz*. This confirms that an effect of the soap is swamping out everything else. In other words, there's something *in the soap itself* that is skewing the measurements beyond its intended purpose. He just wanted the soap to make the water cling better, but it ended up perturbing the very thing he was trying to measure (loss) way too much. It's a l
Re: [Elecraft] Output power being eaten
Happy New Year, I think N7WS has shown that when that window transmission line gets wet, its loss goes way up. So some of the change you are seeing in rain/snow conditions could be due to this higher loss. Al W6LX/4 > > My experience with antenna's changing due to moisture is with my > balanced center fed wire which uses window line for the feed. It > accumulates moisture, frost, rain, snow, and ice. The change I do see > is due to the velocity change of the balanced feed. My measurements of > a couple of years back indicated the length of the line changed > electrically thus a velocity factor change. Any loss, wet or dry, under > matched conditions was not measurable over a length of 100 ft on 20M. > Therefore, I would expect the mis-matched loss to be about as the book > say. Again, either wet or dry. > > 73 > > Bob, K4TAX > __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KAT500 Attenuator
Have we, in fact, established that this attenuator is enabled at any point of the tune cycle? Because if not, then we're all spun up for nothing. Is it reasonable to believe that the attenuator was one of those design elements that might have been deemed necessary at one time but then the designers changed their mind for the finished product? I think so. The mysterious R7 may have been left off of the final circuit board precisely to cause such a bad mismatch that it would be obvious to operator, software, or both, and so that corrective action could be taken. Al W6LX/4 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] HELP! XFINITY SHUT OFF INTERNET DUE TO HAM ANTENNAS
Jim beat me to it. I was also going to urge you to transmit as much as possible on 20 meters with the highest power you can. The idea is to become a hair ball that Xfinity can't swallow nor can't cough back up. If anybody comes up to you to complain that you're still causing outages, use the same twisted logic that Xfinity used and tell them, "That's impossible. It couldn't be me because Xfinity has already disconnected me." Al W6LX/4 >>> and 3) operate at you highest practical power >>>level as often as possible. >>>73, Jim K9YC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] A suggested VFO parking place
7030.0 - on the peak 7029.7 - a little down the south slope, couldn't make it up the last crag 7028.9 - in the car at the trailhead parking lot Al W6LX/4 On Monday, September 20, 2021, 10:11:55 PM EDT, Wayne Burdick wrote: Gaussian describes the shape of the QRP frequency distribution *and* the topology of most SOTA peaks. So please, if you don't make it to the top, move off frequency in proportion :) Wayne __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] A suggested VFO parking place
If you regard QRP ARCI as a de facto authority on QRP in the US, they recommend 7030, and they call it a 'center of activity' rather than a calling frequency. I take that to mean we should imagine a Gaussian distribution of activity above and below this center. I imagine a standard deviation of perhaps 500 Hz, but that's just me. I grew up thinking it was 7040 as well, but it has changed more than once in recent times. Al W6LX/4 >>>On Saturday, September 4, 2021, 01:38:00 PM EDT, Dan Presley >>> wrote: >>>The longstanding QRP frequency for 40 has been 7040-European 7030. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3S audio quality issue
Hi, Mike, This issue comes up regularly here. It sounds like this is a new problem with the K3S? Or has it always been like this? There are so many settings that could have changed. You'd have to list them all for us. I assume that you know about the receive equalizer, AFX, and DSP, all of which have an impact on the received audio. Only you can tell us if any of these are activated and if so, to what degree. I couldn't help but wonder... if it sounds like mistuned USB, what happens if you just tune the VFO a little bit lower? Does that change anything for you? Let us know and we'll do our best to help you. R, Al W6LX/4 On Tuesday, August 17, 2021, 05:11:25 PM EDT, Mike Kholodov via Elecraft wrote: Listening to the K3S audio had become very fatiguing for me as of late. It sounds like hum or carrier is mixed in at the low end. It is very similar to the sound, if you tune a little bit higher on USB. I checked the same stations on my KX3, they sounded great. Used the same headphones in both cases. Has someone had the similar problem and is there any solution before I request the official support? Thanks,Mike, AB3VN __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to alor...@sbcglobal.net __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] A or B?
The Logikey keyer by Idiom Press lists no less than ten "emulation options", or keyer timing modes. They are numbered "V0" through "V9", including three different Curtis A modes, three Accukeyer modes, and others. "V0" is the best timing I've ever used on a keyer. I don't know whether it's A, B, or other, but it's accurate, smooth, and feels right. Al W6LX/4 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Question about antenna matching
Thanks to Al N1AL, Jack W6FB, and Dave AB7E for great information that helped me a lot. I'm in the circuit simulation business, after all, and I confess that I was just being lazy, so I ran some simulations that confirmed what Dave, in particular, had said. As suggested by Dave, I chose typical Q values of 100 for the inductor and 1000 for the capacitor. Then I simulated as many points as I could on the entire Smith Chart to see 1/ if the tuner could tune each point to 50 ohms, and 2/ what the power loss was in the tuner at each of those points. Then, I discovered that K6JCA had already done this on his excellent blog at: https://k6jca.blogspot.com/2015/03/notes-on-antenna-tuners-l-network-and.html . The guy is totally professional and exhaustive in his discussions. I really admire his work. Anyway, it turns out you can make a graph of power lost in the tuner versus phase angle of the load. As you might suspect, 'easy' loads of 5 or 500 ohms resistive (SWR = 10:1) don't tax a tuner as much as reactive loads do. In fact, they're near (but interestingly, not at) the areas of *minimum* power loss. Whenever an antenna tuner is reviewed in QST, resistive mismatched loads are usually used. I'd like to see tuners tested with reactive loads, but the number of loads required to do this from 160 to 10 meters would be enormous. I see why resistive loads are preferred, because you can re-use the loads on every band. I'm frustrated by imprecise statements like, "This tuner will tune an 8:1 mismatch." What does that mean? There has to be a better way for manufacturers to spec the exact impedance ranges that their tuners will tune. I like the method that I used, which shades a Smith Chart in color based on the two criteria I listed above. One picture would tell you all about a tuner's effectiveness. No real tuner can tune the entire Smith Chart, but the more of the chart that is covered, the better the tuner. And if you can shade the areas of higher tuner loss in red, then that would also tell you an important piece of information. (However, to generate such a plot through measurement you'd probably need a very expensive load-pull setup, which is a totally separate discussion.) For the L-network I simulated, a particularly difficult 10:1 load was near the 7 - j30 ohm point, which is toward the bottom edge of the Smith Chart at a phase angle of 282 degrees (or -77 degrees), and a similar point near the top edge. The lower impedances with capacitive reactance were definitely the most difficult (using power loss as the measure of 'difficulty') for the tuner to handle, which Dave stated in his post, while the high impedances with inductive reactance were generally more difficult. If your antenna must be mismatched, and you're using an L-network tuner, you want it to be > 50 ohms with a little bit of capacitive reactance, or below 50 and inductive. By the way, K6JCA actually put the Elecraft KAT500 through this simulated evaluation and it tested so well that he ended up buying one. Al W6LX/4 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] Question about antenna matching
This question is about how manufacturers spec the matching range of their antenna tuners. If an antenna system presents an impedance of 5 + j0 ohms to the antenna tuner, that's an SWR = 10 to 1. But, an antenna impedance of 50 - j143 ohms is also SWR = 10. So is 110 - j200 ohms. When a manufacturer like Elecraft says, "Our antenna tuner can match a 10:1 mismatch," does that mean the tuner can match the first case above, the second case, the third case, or all three? I guess what I'm asking is, are all of the impedances above equally difficult for the same tuner to match? Or is one 'harder' than the others? It would depend on the values of the L and C in the tuner, wouldn't it? Which implies that certain 10:1 mismatches are not tunable? Thanks, Al W6LX/4 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] The next generation KAT500
The recent thread on small and inexpensive vector network analyzers made me wonder if and when someone will make either a manual or automatic antenna tuner with something like one of those VNAs used as a front panel display. With the VNA in Smith Chart format, how cool would it be to tune the tuner and watch the antenna impedance move toward the center of the Smith Chart? The calibration coefficients of the VNA could be set at the factory and stored in EEPROM since they wouldn't change much over the life of the tuner other than some temperature and aging effects (but even the cal vs. temperature could be pre-measured at the factory). To my knowledge all commercially available tuners simply display the measured SWR as a single number; providing a Smith Chart (or rectangular graph if you wish) swept over frequency would be a quantum leap in the information presented to the user. Maybe if and when Elecraft decides to design the next generation of the KAT500, or maybe this has already been done and I don't know it? Al W6LX/4 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] Gurus
When this subject appeared last week I had composed a reply but then slept on it and canceled it the next morning, as I probably do 80% of the time. In this my second attempt, let me say that I've always been amazed at the power wielded by Rob Sherwood. Thousands of hams hang on his latest tests. If he deems a new radio exceptional in some way, that can mean many millions of dollars for a manufacturer. And yet, if there were no such thing as gurus on the web and at places like Dayton expounding about how Brand A is better than Brand B, how would you answer the questions, "Do I like this transceiver?," and, "Is it any good?" You'd probably get on the air and use it, and decide that way. But we constantly have gurus telling us that Brand A is the 'best' which horrifies us if up until now we liked Brand B better. Against our personal experience we flip-flop and say, "Gee, I used to like Brand B, but Brand A must be better because the gurus say so." Yet, there will always be guys who'll be tortured owning a transceiver that has the 2nd highest dynamic range, or the 3rd best distortion. Never mind if they can't actually hear the differences. It's how a rig *sounds and feels* during actual operating that's most important. Not the numbers. For instance, Wes made a comment about his tuning knob, and although some of you might have laughed at that... it's darned important! That's the kind of thing I'm talking about. Here's my opinion on ranking receivers by 2 kHz 3rd order dynamic range: almost any modern receiver has enough dynamic range to make this ranking more and more meaningless as time goes on. Sherwood himself has said that 90 dB or above is plenty enough. To understand why, see this post from 2016 by one of the old guys on this reflector: http://elecraft.365791.n2.nabble.com/K3-The-Way-We-Rank-Receivers-long-td7623639.html Lastly, if you've been enjoying your rig for years and then hear someone else complain about a flaw you weren't even aware of, don't panic. There are a million reasons why his concerns might not involve you in the least. Above all, have fun. Al W6LX/4 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Delivery of the K4
If by 'most infectious' you mean highest number of cases per 100K residents in the last 7 days, that distinction goes to Arizona. If you mean most deaths per 100K in the last 7 days, CA isn't even close to Kansas in the top spot. But we Californians know what you meant, and thanks for the sympathy. Source: CDC COVID Data Tracker. Al W6LX On Tuesday, January 5, 2021, 03:54:54 PM PST, Paul Van Dyke wrote: Considering that California is now the most infectious state in the United States for Covid-19, I suspect the Eric and Wayne have their hands full just being alive, and making sure their, friends, family, employees are staying alive they have been through going through living h*** for over a year.. Paul - KB9AVO __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to alor...@sbcglobal.net __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] [OT] Fires
So I read not only K6XX's report, but the entire issue of the Jug. http://nccc.cc/jug/2020/09sep2020.pdf . I am completely floored by the complete destruction of Bob's place. Bob, I don't know if you're a believer, but I for one am praying for strength for you, my friend. My impression of the Bobcat fire here in Los Angeles, which got to within 2 miles from me and is still burning 38 days later, is similar to Bob's: fire agencies simply let it burn for days without any urgency whatsoever, letting it advance into backyards in the northernmost reaches of Arcadia and Monrovia before kicking into firefighting high gear at the last possible second. In strangely similar fashion, the news media never really reported with any energy on the Bobcat fire. I still can't understand the almost total ignoring of this fire for so long. So I resonated with Bob on this point, and for this reason I refute W6GJB's claim that resources assigned to southern California deprived northern California of the same. It seems that *nobody* had the resources they needed. What a shame. Hang in there, Bob. Please let us know if you've started a gofundme page or something like that. Al W6LX >Bob, K6XX, suffered a total loss of his mountaintop home and QTH >in the August 2020 SCU Complex fire. He writes about it in great detail >for the NCCC September 2020 Jug, reflecting on his fire-safe preparation, >how opportunities were missed to use those resources to save his property, >and the rebuilding process he now faces. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] [OT] A Very Quiet Day
Power was shut off to my noisy urban neighborhood yesterday while crews replaced a power pole. For a long time, I have wanted to check my HF noise floor when the power is out, and yesterday was my chance. For days like this is why my station is solar-powered! I expected to be surprised but I was absolutely blown away by what I heard. The 40 meter noise floor was at least *17 dB* lower than normal. I could hear layers and layers of signals that I never knew were there. Nets I never knew existed… I mean, have you heard of the Montana Sheepherders net, for pity’s sake? A midday 40 m pileup on a SOTA QRP CW station in Texas that I never would have had a prayer of hearing normally. The noise was so low that I could hear way, way down into the intermod of SSB signals—and most of them were quite yucky. I heard birdies and crud from washing machines from what must have been three blocks away. I heard the 7150 kHz 5th harmonic of a local AM station. By measurement on the P3, I confirmed that all of these signals would have been completely under my usual noise floor. On 20, it was so quiet I almost believed that the K3’s receiver had failed. WWV was coming in at a 56 dB signal-to-noise ratio. Interestingly, 80 meters was also quieter, but not by as much. I’m not complaining about nearly 10 dB less noise, but it’s too bad that power was turned on before dark, before I could really evaluate the conditions. When it gets this quiet, there are no ticks, crashes or noise transients of any kind... just a gentle rushing sound, so it ‘feels’ even quieter than it is. It was every bit as quiet as a forest Field Day a hundred miles from civilization. Yes, radio was amazing yesterday for six glorious hours. R, Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] New antenna works!
I'm glad Dave added that to the end of his message, because each time the topic of multiband antennas comes up, we are told, "That's too lofty a goal for one antenna. Just put up a resonant antenna and all your troubles will be gone." All except for the problem of operating on all bands without having to put up 9 resonant HF antennas, that is. I think we do a disservice to the hundreds of hams reading this by discouraging them from multiband operation just because we deem it too "noisy" or "lossy" or "inconvenient" or whatever. If a man or woman, knowing full well the consequences of his or her actions, chooses to utilize a single, horizontal antenna of no particular length, ultra-low-loss feedline long enough to reach the shack, and a low-loss homebrew or commercial manual antenna tuner to operate on all bands, then who are we to tell him or her that they shouldn't? To do so has always struck me as presumptuous. Incidentally, can we do two things? Can we all get over the gross assumption that we continue to make, that when someone mentions feeding an antenna with "balanced line" that must mean Wireman #553? There are better alternatives. If our beef is with Wireman #553, then let's be on with it without condemning *all* forms of balanced line. Secondly, antenna tuners are not necessarily lossier than the aggregate of cables, connectors, wattmeters, filters, switches, elbows, lightning arrestors, baluns, autotuners, &c., &c., that many folks use. Everything has loss, but in effect we trade that loss for some other valuable function... like being able to QSY anwhere, easily. To give you a data point, on 12 meters my station has a max loss (from transmitter to the antenna feedpoint) of 1.6 dB. I'll put that worst-case number up against anybody's long run of coax through all the other junk from their transmitter to their antenna. Folks, you should not feel inferior for having chosen to operate on many bands with an antenna tuner. I think the case could be made that the *resonant* antenna is the compromise, giving up all band operation for some other desired function. And sadly, sometimes that compromise is made just so they can say that they're not using a tuner! Al W6LX >>>Multi-band antennas are fine as long as you recognize that they are a >>>compromise. >>>Dave AB7E __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Matching resonant antennas
Using AC6LA's Line Loss calculator, and making the following assumptions: Line impedance: 420 ohms, (1/4" copper pipe spaced 4 inches apart) SWR at antenna: 14.0 (Z = 30 ohms) Line attenuation: 0.0266 dB/100 feet (Duffy, "RF Two Wire Transmission Line Loss Calculator", owenduffy.net/calc/tl/twllc.htm) Length of line: 500 feet (conservative estimate that probably represents a worst-case?) Frequency: 10 MHz ___ Total Line Loss = 0.891 dB >>>I've seen pictures of those SW transmitting plants and always assumed that >>>they >>>must have been very efficient. Upon reflection---no pun intended---now I'm >>>not >>>so sure. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] Fw: [OT] QST Scan
I have the volunteer I needed to scan QST for me. Thanks, everybody. Al W6LX - Forwarded Message - From: Al Lorona To: Elecraft Reflector Sent: Friday, July 17, 2020, 01:41:11 PM PDT Subject: [Elecraft] [OT] QST Scan This is a request for a favor... to anybody who's got a complete QST collection... would you be willing to scan 1 page from 1995 and send the scan to me? The low-res scanned copy on the QST Archive at the League's web site doesn't clearly show a detail that I'm interested in. If you're able and willing to help me, please contact me off-list: alor...@sbcglobal.net. And thanks *very* much in advance. Regards, Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to alor...@sbcglobal.net __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] [OT] QST Scan
This is a request for a favor... to anybody who's got a complete QST collection... would you be willing to scan 1 page from 1995 and send the scan to me? The low-res scanned copy on the QST Archive at the League's web site doesn't clearly show a detail that I'm interested in. If you're able and willing to help me, please contact me off-list: alor...@sbcglobal.net. And thanks *very* much in advance. Regards, Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] [OT] Failed Day
Not many FD reports on the reflector this year; Covid obviously took its toll, so I'll offer this (sad) report. NR6TT's Field Day was a Failed Day this year. Wanna know what it's like to break your slingshot on the very first attempt to use it? Good thing my 14-year-old was there to throw a few fastballs 20 feet up into the trees. And then this: Isn't FlexWeave wire supposed to be the Next Big Thing? As soon as I started to tension one end of the doublet, it broke. Man, it twanged! And not at a soldered joint or wrapped point... but right in the middle of the span! I was incredulous. Luckily, I brought a butane soldering iron, which barely worked at the 3000 foot elevation near Lassen Peak. Somehow I managed to repair the break, and spent more time in 100 degree heat putting up the antenna again, then thinking I could outsmart Murphy (!) I tried tensioning the *other* end of the antenna. And it snapped again-- in a different spot!! Yes, this was the 3rd Field Day I put up the same antenna, but what the heck? Is Flexweave that easily snapped? I'm not impressed. Well, as you know, when your antenna breaks, your Field Day is pretty much ended. I guess we could have used a piece of the broken Flexweave as a random wire, but my heart wasn't into it, for a number of reasons. (We had planned on operating on 40 meters only.) Instead, we went swimming in Hat Creek, had a great salami sandwich dinner and read stories to each other until we fell asleep. So it wasn't a total loss. Total score: 0. Time spent with Blaise: Priceless. Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3 QSK Timing
I have always felt as K9ZTV does. I don't mean to speak heresy here, and I would never deny anybody's right to use full QSK, such as when chasing DX. However, I have never felt the need to hear between dits. Between characters or words seems more than enough for me, especially at the CW speeds where most people exist. Plus, I've always felt it was rude to be interrupted during a transmission for anything other than an emergency. One time, when I was a novice, the other guy suddenly broke in frantically: MUST QRT QRT LOST BIAS. That was definitely a valid emergency. I could almost smell his final getting red hot and hear the plate current pegging the meter that evening. Al W6LX >>>For any practical purpose needed by amateur radio operators that I can think >>>of, the ability to hear between elements is not a life-and-death virtue. >>>The ability to hear between characters is by far magical enough. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] CW rise time setting
I used: 1/(1+exp(-x)) where x = the pulse train. I then modulated a 7 MHz carrier with the result (although the results don't care what the RF frequency is, of course). Al W6LX >>>Which sigmoid function did you model, Al? __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] CW rise time setting
I used to think that the rise and fall times of the CW pulse didn't really matter much to the sideband levels; I believed that it was more a function of the waveshaping, especially at the corners of the pulse. But I just ran a quick simulation of a pulse train going through both a raised cosine and then a sigmoid filter (because those two have been mentioned in this thread) and the rise time definitely does affect the pulse sidebands. The reduction in the sideband levels (what some folks here called 'clicks'... not sure that's a good name for this) varies depending on where you measure it, but in general the sidebands will drop anywhere from 0 to 12 dB-- sometimes less, sometimes more-- when you go from 2 msec to 8 msec rise/fall times. For instance, arbitrarily choosing an offset of 500 Hz from the carrier, the sideband drops by 11 dB for the longer rise time. That turns out to be a fairly typical value. And by the way, in general the sigmoid does a better job than a raised cosine. Arbitrarily defining the occupied bandwidth as the -60 dBc points of the spectrum, and using the sigmoid function with an exponent of -1, the bandwidth of the rise time = 8 msec pulse is 420 Hz versus 640 Hz for the pulse with 2 msec rise time. It's not an enormous difference, but it is something. Anyway, there's another data point for the discussion. R, Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3 QSK Timing
Really interesting, Vic. Here's a minor point: Instead of measuring to the "first whiff" of RF, I'd probably measure to the point of 90% of max RF value. This is because the rise time of a pulse is usually defined as the time to go from 10% to 90% of the final (peak) value. Congratulations on your new scope. Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K4???
Jim is right. Those of you outside of California would probably have a difficult time imagining how differently we are experiencing the lockdown-- which is an aptly descriptive noun-- here in California. The latest long-term outlook we received from Sacramento earlier this week made most of us gasp. We're running two or three months behind the majority of the country. It doesn't help that confusing, conflicting, or downright false information abounds. Patience. Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] RX Ant K3 Preamp vs External Preamp
Precisely the intended application for a visual aid to show where the sensitivity of the receiver sits relative to the band noise. W3LPL is absolutely correct in asserting that relatively few know how to optimize their settings for a given band condition. Just sayin'. Al W6LX > wrote: >This rule-of-thumb is very valuable on the lower bands because it helps >the operator select the proper receiver attenuator and RF preamplifier >settings for optimum dynamic range while retaining full system sensitivity. >You'd be surprised how few DXers and contesters understand this simple >principle, and fewer still actually do it when they sit in front of their >receiver. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3/K3S receiver and high-precision frequencydetermination?
It's a good thing I didn't carry through on my plan to operate the K3 with a paper in the place of the top cover! That was a close call. Seriously, don't *all* DDSs/PLLs/synthesizers/SDRs (and, thus, all modern transceivers) tune in steps? How is the tuning step related to the stability of an oscillator? I'll answer that: it isn't. Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K4 S-meter characteristics
Now that the K4 has exact knowledge of its gains and losses through the preamps, attenuators, splitters, bandpass filters and so forth, could this enable an alternate way of visualizing the receiver's range? This alternate measurement would be quite useful in setting the controls optimally for any situation. Imagine a scale -- I suppose it would be in dBm -- showing the K4's total dynamic range. Say it's 100 dB in total. The lowest point is the minimum discernable signal (MDS); the highest point is the damage level, or if that's a bit too frightening, call it the maximum ADC level or something else to denote it as a Level Not To Be Exceeded. Since the K4 will know not only what the noise floor of the band you're listening to is, but the absolute value of that level in dBm, the scale can be annotated with a dynamic marker to show where the band noise falls in that 100 dB range. I'm calling it 'dynamic' because it'll vary a few dB as band noise does, but it will sit at a calibrated level, relatively motionless on the scale as Wayne described the S-meter doing. As the operator kicks in more gain by turning on preamps or turning up the RF Gain, the scale shifts downward by the same amount. For instance, if the scale was showing -120 to -20 dBm -- a 100 dB range -- and then the operator turns on a 10 dB preamp, the scale must change to -130 to -30 dBm, because the preamp has made the receiver more sensitive while also reducing the max permissible level. Conversely, if the operator turned on 10 dB of attenuation, then the scale would shift upward to -110 to -10 dBm, indicating clearly that sensitivity is being sacrificed for greater large signal handling capability. The noise floor, being a relative constant, would move closer to the bottom of the window, or rather, the window would move relative to the noise floor in such a way as to place it 10 dB closer to the bottom end. So actually, as I'm thinking about this, the meter wouldn't move at all. It's the noise marker that would float higher and lower within the window as you varied the controls, just as on an S-meter. I guess what I'm describing here is more or less an S-meter calibrated in dBm! But perhaps the best reason for looking at the receiver this way would be to tune the controls precisely for a given noise floor. Twenty meters, with its -120 dBm noise floor, will require one combination of preamps and/or attenuators. On 80 meters, if the noise is, say, -100 dBm, the operator knows (because he can see the graphic) exactly how much attenuation is acceptable while still keeping the band noise marker in the operating range. It would behoove the operator to keep the noise floor marker near the bottom to 1) give him the maximum dynamic range under those conditions, and 2) to avoid becoming "my K4 is noisy" guy. Presumably, as each K4 goes through RF calibration at the factory it will know exactly the gain of each preamp, attenuator, filter, and splitter in its path. The scale could be custom for each individual unit, although I wouldn't want to start any "my K4 is more sensitive than yours" wars. I leave it to the programmers to decide on the specific eye candy of such a readout. I for one would find this type of meter fun and useful in getting a mental picture of where in dynamic range space the receiver is sitting. Can anybody see any flaws in this idea? I can foresee at least one. I don't know how the front end of the K4 will work, but if it is constantly moving the receiver range in response to what it hears, that is, in response to the total amount of power incident on its antenna port, then perhaps that might pose a real challenge to giving this type of feedback to the user. I don't know. Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3 on SSB
Jack beat me to the comment I was going to make. Far be it from me to contradict a seasoned contester like W3LPL, nor to dismiss the comments of many others, but I wonder how many "the K3 sounds bad on SSB" comments occur because of operator error in setting the AGC and gain controls improperly? In my experience, a number of such declarations are due to not knowing how to set the controls to optimum. Then, at some point, these perceptions attain legend status. Now, if W3LPL's assertion is that the need to know *how* to set those controls properly poses a problem for contesters, that could be a valid point. If, for instance, the newest Flex 1,000,000 just works out of the box, with the default settings, that may appeal to contesters and I understand that. However, it's never bothered me that the default AGC parameters of a K3 aren't optimum for me... that's why the controls are variable, no? I've learned to set them to obtain incredible SSB readability. My settings aren't magical; I got them from others and are based on my own measurements (which others have dismissed over the years, I don't know why). Al W6LX >>> With the default settings things can get quite jumbled and the audio is not >>> clean and crisp. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] Results of 'survey'
Thanks to all who replied to my question about gap width on your paddles. I got answers ranging from 0.6 mil (15.24 micron) to 30 mil (0.762 mm), a spread of 50x! This obviously comes down to personal preference. I had to smile at the reply from George, W3HBM: "Whatever feels good to you! Enjoy!", which was George's tactful way of saying, "Stop overthinking it, dude!" Point taken, George! What spurred this question is I recently bought a new paddle and it came from the factory with a phenomenally small gap-- much smaller than I had used all my life-- but yet it felt okay. I let it out a little bit, and as I did I wondered if I was violating some universal rule of thumb. I wasn't. Thanks, everybody! Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] [OT] Gap Width
Hi, Everybody, What do you set your gap width to on the contacts of your paddles? Is there an optimum gap width, or is it totally a personal preference? Because this is an off-topic post, if you reply to me please do it directly. Thanks! Regards, Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] The Phone Call
I just read the Elecraft December Newsletter, so I made a quick phone call. It's still morning over there. Big Radio Company: How may I direct your call? Me: Yes, hello, I'd like to speak to your CTO. BRC: Oh, I'm sorry sir, but I can't do that. Me: How about a co-founder? BRC: No... Me: Why not? I'm about to buy a new radio, and it's down to Elecraft and you guys, and Elecraft says I can go hang out with one of the big wigs and play radio, so I'm calling you to see if you'll match that offer. You know, maybe I can come over and hang out in your ham station -- you do have a station, don't you?-- and your big wig can come out and have a soda with me, and we can trade stories and shoot the breeze and then call CQ on 20. Yeah? BRC: No, sir, I'm sorry. To tell you the truth... we don't even *know* who the CTO is. Me: Excuse me? BRC: We see important-looking people pass by all the time, but we don't actually know which one is the CTO. We're a big conglomerate now. Me: Well, maybe you can find someone under him, like the VP of engineering. I'd like to meet him. Or her. BRC: Oh, no. That's not possible. . You see, he doesn't actually design any of our products. He has a team working under him, and they do all the work. He does select the knobs that go on the radios, though. Me: The chief knob-picker, eh? Gee, I was hoping for someone who knows how to match impedance, or optimize a sigmoid response. Got any amplifier experts? BRC: Not really. Me: AGC gurus? BRC: Not that I know of. Me: Anybody who solders? BRC: Oh, yes! You could have lunch with Maria. She's our absolute best solderer. Me: Can she dig a signal out of the noise? Does she like hiking? BRC: Me: Never mind. You know, I'm glad I called you. I think my mind is made up. Good-bye and thank you! BRC: Good day, sir, and thank you for calling. Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Center-fed antennas
Fair enough, but it kinda goes without saying that in a group FD with 1 station per band they'll use resonant, single-band antennas. If this is our best argument against the 'multiband dipole', then that antenna still holds its own pretty well in a multitude of other situations. I have always found a deep resistance and opposition to this antenna. Whether it's an unwillingness to use antenna tuners, which many hams have, or an undue fear of noise, which some hams have, or a belief that open-wire line is noisier/weirder/harder/impossible-to-go-through-walls, which many hams believe, the visceral reaction against this antenna always amazes and baffles me. Please forgive my belligerence... the Dodgers lost and I've been in a sour mood all day. Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Center-fed antennas
Precisely because of this objection and countless others, is why I expressly stated, "...at the expense of any other possible advantage." I think we all understand that there's no magic antenna. The 'magic' of the antenna we're discussing here is simplicity, all-frequency operation, and high efficiency. No other magical claims are being made. Al W6LX >Yes, however ... a center-fed dipole long enough to be moderately close >to a half-wave at 40 will develop a serious case of acute lobe-itis when >operated at higher frequencies __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] Center-fed antennas
My experience with single vertical or sloping wires is exactly the same as AB7E's. I have, over almost twice as many Field Days as Dave, come to a similar conclusion, with the slight difference being my preference for an "all-band dipole" fed with balanced line. This obviates the balun and reduces feedline loss to negligible, so obviously I am maximizing efficiency at the expense of any other possible advantage. (I can usually hear much better than I can be heard... so thus far this has been a valid decision.) To sum up what I and what I think Dave are saying, you can't beat a horizontal, center-fed wire up as high as you can get it. Its simplicity, the flexibility it gives you to QSY (with a good tuner), and its high efficiency are almost unbeatable. As a side note, the center-fed horizontal wire I have used here at home is totally non-resonant. I don't even know how long it is. Once you give up the obsession with resonant antenna length, you gain a huge freedom of choice. In the bottom of the sunspot cycle, these advantages are somewhat reduced because an op, especially on Field Day, might opt to forget about any band higher than 20 meters -- and these days even 20 is questionable. This means you can probably make do with coaxial cable and a balun for operation on 2 or 3 bands but the general idea still holds. Al W6LX >Yes, a center fed normal dipole with the middle (high current portion) >higher off the ground (say 50 feet for 40m) and a common mode choke at >the feedpoint would almost assuredly perform better. > >73, >Dave AB7E __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 failing on 160...AGAIN!
And not just antenna and feedlines, but the AC wiring in your shack, the potential EMI problems, etc. This is why I keep saying that hams badly need a tutorial -- perhaps something named, "What to Expect When You Run High Power". There are lots of us, including me, that could learn about the extra precautions and checks one needs to make when you put an amplifier into service. Jim, maybe you're the right guy to do it? >>>High power can expose antenna and feedline problems that are not evident >>>at 100W. >>>73, Jim K9YC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] New K1 Kit
1/ It always seemed to me that this method heats up the components much more than using a simple soldering iron, where you can pause between soldering each pad to allow heat to dissipate. 2/ Is that a capacitor standing up at about the 1:12 mark? Not good. Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] portable antennas and rigs going through airport security
I am sure there are just as many horror stories as "I've never had a problem" stories. Such as the time I was carrying a small Ten-Tec shortwave receiver and was detained for almost half an hour while the agent stared and actually asked me, "Voices come out of this thing?" Meanwhile, an alarm blared for several minutes without any response from TSA whatsoever. Someone could have gained access to the tarmac in that time and planted a bomb. But the little Ten-Tec was deemed more of a threat. Be prepared for any response, subject to the whim of the agents. Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] K4 and Linux Infrastructure
You guys have now reached the scenario I was trying to ask about last week, but obviously didn't make myself understood. When I asked if the K4 would be able to 'talk to the outside world', I meant an ability to initiate communications with a web site, a server, or something else. Yes, allowing users to get down to the operating system would probably be unmanageable. But what about loading 'apps', in the same way that you install apps on your phone? I could see a logging app, a reverse beacon app, or something else that would add real functionality to the radio. I'm sure that's been talked about... and I wonder what the thinking is along these lines. R, Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] High Resolution K4 JPG/TIF?
Thanks for posting that, wunder. It was bound to happen... a radio whose font size will *force* me to wear my glasses while operating it. >>sigh<<. Here's a really dumb question: Is the Ethernet bi-directional? We know that the radio can be talked to (controlled) by some external thing. But can it talk to the outside world, using its screen and mouse? Can it initiate communications with some external thing? How long does it take to boot when you turn it on? Is it like the old days when we had to wait for filaments to heat? Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Level of K3S audio out to digital apps on Mac
Adding on to the RF part of the adjustment described by Mr. McGraw below, the idea described in this old post-- I still contend-- would be a very useful graphical way of making the adjustment. Not coincidentally, I wrote it in response to a similar post by Bob almost two years ago: http://elecraft.365791.n2.nabble.com/A-very-desirable-capability-tp7633678p7633779.html On Wednesday, May 22, 2019, 4:09:36 PM PDT, Bob McGraw K4TAX wrote: Regarding receiver set-up implementation, it is usually best when the no signal band noise is some 10 dB above the noise floor of the receiver. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] Measuring SWR (Long)
There's always a lot of discussion about measuring SWR, low SWR values, SWR lights not lighting up, etc. Here's something that might give you a better 'feel' for SWR. Imagine that you measure your forward power at 100 W and your reflected power at only 1 W. You'd probably be very happy about this. Congratulations, your SWR would be 1.22 to 1. Pause for a moment and let it soak in that an SWR of 1.22 is fabulously good. Once you get to this point, below which we're dealing with reflected power that's less than 1% of your power, or four-hundredths of a dB, it's not worth doing any more to your antenna system to improve it. No trimming, cutting, raising, lowering, hanging stuff from it, adding remote tuned things, nothing. You're done for the day and can now get on the air! If the reflected power were 4 W, which would still look pretty small on the meter, the SWR would be 1.5 to 1. A lot of people might be bothered by an SWR of 1.5, but really this is still very good and it's probably not worth going back up to the antenna to mess with it any more. Most importantly, the station on the other end cannot possibly hear the difference between your 1.2 and 1.5. At this point you may be saying, "Yeah, but my rig/amplifier/other thing isn't happy unless the SWR is below 1.5 to 1, so I would still have to do more work." Okay, that's fine, but my point is that the absolute number 1.5 nonetheless represents a system that is working quite well. Let's allow the reflected power to increase all the way to 10 watts! At that point, your SWR would be about 2 to 1. Sounds pretty bad, but surely if you were stranded in the desert and had to use your KX3 and a wire to get help, you'd be happy to have a match this good. Now, let's look at a certain type of SWR meter found in virtually every HF rig out there that uses a directional bridge, a diode as a half-wave rectifier, a filter capacitor, a resistor, and a readout of some kind - analog meter, digital display, or other. These types of SWR meters are very common. There's one in the K2 (it's actually in the KPA100), one in the K3, and probably every other rig out there. And those Birds, MFJs and Daiwas have them, too. This type of circuit turns RF voltage into a DC current, usually using either a germanium or Schottky diode, because these diodes have the best sensitivity due to their low forward voltage drops: 0.3 V for the germanium, and 0.4 V for the Schottky. Let's say that our directional bridge, when 100 W is in the forward direction, delivers 10 V to the forward Schottky diode. In our example above of 1 watt reflected, the reflected diode would see 1.0 volts from the reflected port of the bridge. Since this is above the diode threshold voltage, the diode would be happy and operating in its linear region where we'd get about 1 volt out for 1 volt in. The meter would correctly read 1.22 to 1. Now say you have your Elecraft rig set for TUN PWR = 10 W, so when you tune up, forward power is 10 watts, and if the SWR is the aforementioned 1.2 to 1, the forward power would produce a little more than 3 volts at the diode and the 0.1 watts reflected would produce about 0.3 volts. Here is where we run into trouble. Since a Schottky diode doesn't fully conduct until we exceed its 0.4 volt threshold, expecting to get 0.3 V out for 0.3 V in isn't quite realistic. The diode's output voltage won't be zero, but it'll be smaller than expected, according to the nonlinear region around its "knee". I measured a Schottky diode and got about 0.09 V at that level. The meter would indicate an SWR of... 1.06 instead of the actual 1.22. This reading is false. There are some things that can be done to the circuit to compensate for this error but I'm not sure how many rigs go through the trouble. Suffice it to say that measurement of very low SWR has a large amount of uncertainty because the detectors get more and more nonlinear as the thing they're trying to measure (reflected power) gets smaller and smaller. Due to this effect (and also due to directivity) every meter of this kind has a point below which SWR measurements are probably wrong. When we see posts here by folks puzzled as to why low SWR measurements from two different instruments don't agree, this undoubtedly is one of the reasons. I chose these scenarios deviously, to illustrate a kind of corner case, but I think you get the idea that errors always exist in any power measurement like SWR. You might say, "But my SuperDuper wattmeter is calibrated by aliens in a metrology lab deep inside a secret mountain in Nevada and I would bet my life on it." Great, cool, congratulations. But I'm afraid every last power meter has errors stemming from mismatch, directivity, nonlinearity and drift. If you simply tune for minimum reflected power you should be good to go, and don't get too hung up on if the meter says "1.2" or "1.5" or "1.0". Remember, once you get down into this zone i
Re: [Elecraft] The case against touch screens
I don't think you guys understood me. I shouldn't have veiled my concern with a tongue-in-cheek post. So I will be direct. I was referring to the physiological event of touching a screen with a finger. It must be just me, because a large percentage of the time a touch screen does not respond to my finger. I have experienced this at ATMs, at the self checkout at Home Depot, at the airport, on my smart phone, etc. When you have to stand there, tapping over and over to get them to respond, touch screens just aren't as reliable, responsive, accurate, or fast as a control. Touch screens are beautiful, but they seem to ignore me. My fingers are low-capacitance, I guess! For that reason, I wouldn't tolerate one any more than I would tolerate a sticky volume control that took three or four twists before the volume turned up. None of us would put up with that. I'm a little surprised others haven't had the same experience as Thaddeus. Maybe they're just too shy to admit it. The next time you tap something on your phone, and you have to tap again to get it to work, I want you to think of me. Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] The case against touch screens
Thaddeus sits down at the rig. Today is the day Bouvet is supposed to come on the air, and thousands of hams around the world must be tuning around at this moment trying to be the first to work the DXpedition. He gets a feeling and tunes low in the band, turning the knob as if he were breaking into a safe. His intuition pays off: he hears a weak signal tuning up, and then... a callsign. It's Bouvet! Instant rush. Instant clammy hands. He reaches to tap the Split button on his fancy new rig's touch screen. He taps again. The screen does nothing. Oh no, not now, touch screen. Please recognize my finger... please! Bouvet turns it over, but nobody has heard them yet, so Bouvet calls again, and while Thaddeus is tapping frantically, time slows down, four seconds feel like four hours, and still the dim-witted screen does nothing as Thaddeus begins all the usual finger gymnastics that people do when they're trying to make their device understand that they in fact want it to do something. The radio sits there stupidly, the DX stops calling, and then the pileup mayhem begins. Thaddeus sits there, stupefied, wondering why those &#^+! engineers at Elecraft decided to put a $@_% touch screen on an otherwise perfectly good radio. For this reason, I will never buy a radio with a touch screen. Ain't gonna do it. So Elecraft, you've been put on notice. Thank you, Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] 1500 W is a lot of power
About two months ago I posted that amateur radio needs a tutorial, 'What to expect when you get an amplifier'. As we see again and again here even basic things like cables, connectors, grounding, and house wiring that work fine at 100 W may be inadequate for 1500 W. We need guidance to study our stations piece by piece to ensure those pieces can handle these power levels without failing or causing problems. Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KAT 500 and open wire
G3TXQ's work here is awesome, as is N7WS's before him. I'm thinking two things: Thing 1 is that, clearly, water really messes up window line's loss. However, I'm guessing that a/ in a place like southern California, where perpetual drought is the new normal; and b/ in an installation where the window line, rather than running perfectly horizontally so water can pool, has a slant, allowing it to shed water; a ham would probably be fine using it. All one would have to do to discourage pooling on a horizontal run is twist the line once every few meters. Thing 2 is that G3TXQ shows matched loss at 6.72 MHz in heavy rainfall increasing from 0.2 to 1.1 dB per 100 feet, which seems totally acceptable for worst-case rainfall. In moderate rainfall the loss increased to only 0.34 dB/100 ft. That's lower than any coax out there. I myself would never use it (for reasons other than water loss), but window line seems like an okay choice for those hams who can't or won't use coax. Al W6LX Glossary: "Window line" = Wireman 551 or 552 or equivalent >>> http://www.karinya.net/g3txq/wet_ll/ __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Non-Resonant Antennas and Chokes
>>> the feedline is a wire dangling from the antenna >>> that isn't connected to anything on the other end. That "dangling wire" is actually *two* wires, and the field of one cancels the field of the other for no net radiation or reception -- at least that is the condition we're trying to achieve. That isn't the same as a single wire which by definition would be a common-mode conductor as you correctly say. Once common-mode current is reduced to a small enough value, then the open-wire line isn't radiating nor receiving. But... you gotta measure the common-mode current to know. I have done so. The instrument used to measure this is quite simple. >>> a choke that doesn't fry with TX >>> power probably isn't doing anything useful. A choke dissipates power only in it's resistance, not it's reactance, and only due to the common-mode current. If the parameters of the choke are chosen correctly for the frequency band, and if the choke reduces common-mode current to a low enough value, then the power dissipated in the choke can be very low even when you're operating at high power. A choke that burns up at high power is certainly not inevitable nor normal and can be fixed by re-designing the choke. There are a number of ferrite mixes available and they seem to each be optimum for a slightly different part of the HF spectrum. There's also the twist that permeability is actually a complex quantity (real and imaginary parts) which has a direct bearing on the resistance and reactance of the choke, but I won't go into that at this time. The posting limit is fast approaching; I'll let you have the last word. Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Slightly Unbalanced dipole?
You guys keep talking about coax-fed antennas. Yes, although it may be easy to
wind coax around a toroid and put it up at the antenna midpoint, that's not so
easy with open-wire line. This discussion was very coax-centric and I wanted to
open your minds that not everybody feeds their antenna with coax.
Balanced feedlines ("window line" or "open-wire" line) can have significant
common-mode current. They're not immune to the effect. (I know you know this;
I'm saying it for the benefit of all.) A device with high common-mode
impedance, located right at the output of the tuner, suppresses common-mode
current on a (balanced) feedline. That's it's purpose.
I'm in agreement with you about the 1/ cause of common-mode current and the 2/
cure for it. I'm simply saying that for convenience's sake, consider putting
the choke at the tuner output.
A choke with high Z to common-mode current, external to the tuner, in a
non-conductive box, with as short a connection to the tuner as possible, does
quite well at suppressing common-mode current. I'll be happy to share my
measurements with you.
There is no coax anywhere in my antenna system. So my solution was to put a
choke with high impedance to common-mode current right at the output of my
antenna tuner. I encourage users of open-wire line to do that.
Al W6LX
>>> In all cases of a radiator fed with coax,
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Re: [Elecraft] Slightly Unbalanced dipole?
By the way, whenever Jim says, "...a very good common mode choke at the feedpoint of an antenna...," he means an antenna fed with coax. For the rest of us, of course, that choke would (should) go at the output of the antenna tuner, whether in the shack or close by. Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Sorta OT - assistive technology assistance
JR - I have a folder of dozens of replies to Elecraft posts that I've never sent. (I try to exercise discipline so that the moderator doesn't have to slap me on the hand.) But your reply said *exactly* what a draft that I had written said. I'm very happy that you expressed the same idea. Building vs. buying, especially when buying is cheaper, is the homebrewer's dilemma. You now have to really want to learn something to build something yourself, and not merely save money. More and more, homebrewing is in effect paying "tuition" to learn by doing. I built a QRP transceiver totally from scratch last year, and virtually everybody I told asked me, "Why?" It took me weeks and weeks and, had I not been blessed with a really good junk box, would have cost me more than a KX2. But... I got to work with some really cool ultra low noise op amps and figured out how to get a half-watt out of a 2N, so putting this particular rig on the air for the first time was my "diploma". I hope your construction project goes well. Please let us know when you get it working. Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Tuners and spurious responses
No, not a null, but a rolloff. When I quoted -40 dB I didn't mean a notch at one frequency, but the stopband level reached by the time you get well into the broadcast band. So that would be -40 dB on all AM stations below a certain frequency. The K3 is a good receiver, but every receiver has its limits and certainly the K3 will suffer once an interfering signal gets above a certain level. A trap or stub would work, but my point was that it would be unnecessary if using a link-coupled tuner. Attenuating a 50 kW station by 40 dB makes it sound like a 5 W station. Al W6LX >>> That said, is suppose it IS possible that a tuner/antenna combination >>> just happened to have a deep null right on the frequency of a nearby >>> broadcast station __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Tuners and spurious responses
Vic, it may well be your imagination (!) but you may also be hearing the rejection that your tuner gives you, particularly to strong AM stations in the broadcast band. My measurements, as well as circuit simulation, show about a 40 dB rejection of AM stations when the tuner is tuned to 40 meters. Circuit simulation of the Johnson circuit shows not all that high a Q, but it certainly is starting to look like a broad bandpass response. (It's actually more high-pass than band-pass.) That's why it's effective against the broadcast band. It's yet another argument to use a tuner like that one. Interestingly, I just moved from a link-coupled tuner back to an unbalanced tuner with balun because my measurements of common-mode current on the transmission line show that the balun is more effective at suppressing it. The link-coupled tuner acts more like a voltage balun which would be okay if the antenna were inherently balanced, but in many cases the current balun suppresses common-mode better when the antenna is in an environment that makes it not well-balanced. When power lines or houses or cars or other things are in the antenna's near field it tends to make the antenna present an unbalanced load to the transmission line. That's when equal currents (not voltages) work better. But I'm repeating what has long been known. If you can measure this stuff, like with an RF current meter, it becomes much clearer. Enjoy your new, cleaner reception, thanks to that tuner! Al W6LX >>> This may be totally imaginary, >>> -- >>> 73, >>> Victor, 4X6GP __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] [OT] FT-8 files
I'd like to obtain IQ baseband files of an FT-8 signal, either separate I and Q files or combined in one text file. Is that easy for someone to do? Thanks, and please contact me off list. Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Portable Battery tests
Howie this is excellent data. Thank you for your work in this area. The table really clearly shows the tradeoffs between cost, weight, volume, capacity and everything else. Alkaline batteries do pretty well for themselves, although I'm not sure why the voltage for 8 cells is listed at only 9.6 V. Is that the ending voltage after the discharge tests? The measurement that caught my eye is the third-to-the-last column, "MAH ACTUAL % OF ADVERTISED" because I abhor false advertising and go out of my way to boycott it. I'd say those at 0.90 and above are acceptable, while the ones at the bottom should be ashamed of themselves. QuickCable at 11% of advertised? Really? Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] help wiring a mic?
The poor guy who started this thread just wanted to know how to wire a mic. It quickly became a discussion of whether he should even use that mic. I don't believe we have that right. The question is about an XLR connector. We should either answer his question or lay out. Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] [K3] factory upgrade to K3(s)
I'm not sure I agree with the exact numbers, Ian. I'm looking at the review from Nov 2015 QST (from the Product Review archive on www.arrl.org ) and it appears that the difference in phase noise between old and new synths is closer to about 3 dB (difficult to tell from the graph) beginning at offsets of *50 or 100 kHz*, not the 6 kHz you cited. At 6 kHz the new still beats the old by almost 20 dB! So, while the old synthesizer certainly exhibits lower transmitted phase noise out beyond 50 kHz offset, the new one is within a few dB of it, and at 50 MHz both seem to meet the -130 dBc/Hz limit you cited. Al W6LX From: Ian White To: elecraft@mailman.qth.net Sent: Wednesday, June 27, 2018 2:45 PM Subject: Re: [Elecraft] [K3] factory upgrade to K3(s) >A big reduction in receiver noise floor and a huge improvement in both >transmit and receive phase noise. That is far too simplistic. Anyone's personal definition of "the better synthesizer" will depend on what range of frequency offsets is more important for their particular type of operating. For HF CW in particular, phase noise at small frequency offsets is of paramount importance and I wouldn't argue with Don's report of "a huge improvement in both transmit and receive phase noise" - but *only* in that specific context. There are also several other advantages that are relevant to high-performance HF CW that could also justify upgrading to the KSYN3A. At close frequency offsets from the carrier, the KSYN3A does indeed offer a large reduction in phase noise compared with the KSYN3 (which itself was already good). But at wider frequency offsets, that situation reverses. According to the ARRL review [1], at all offsets beyond about 6kHz, the older KSYN3 continues to have a lower noise floor than the newer KSYN3A "upgrade". Performance at wider frequency offsets, 10-100kHz and beyond, is of much greater importance in VHF-UHF contesting. This due to a combination of factors. The strongest signals at VHF-UHF are often much stronger than on HF, due to the use of high-gain beam antennas; and also the weakest signals are *always* much, much weaker due to the lower levels of natural background noise. These two features stretch the requirement for dynamic range on VHF-UHF far beyond those for which most HF transceivers are designed. Anyone transmitting wideband phase noise has a much greater risk of raising the noise floor of many other stations across the whole contesting segment of the VHF or UHF band. Running the numbers reveals that anyone aiming to be a Big Gun in VHF contests has a responsibility to keep their wideband transmitted noise floor below about -130dBc/Hz at frequency offsets of 50kHz and more [2]. This can be a major engineering challenge, and the performance of the transceiver is almost always the most important building block. The KSYN3A just about meets the -130dBc/Hz noise floor target at frequency offsets of 10kHz or more... but according to the ARRL review [1] the older KSYN3 achieves it much more comfortably, with 10-15dB to spare. I have both a K3S and a very early-model K3. The K3S (with the KSYN3A, of course) is used for HF contesting where smaller frequency offsets are important. Meanwhile the old K3 is now used as a transverter driver for 144MHz and above - and for that particular purpose there are very good reasons *not* to replace the original KSYN3. 73 from Ian GM3SEK [1] http://www.arrl.org/files/file/ProductReviewsForDeb/2015/pr112015.pd f [2] https://thersgb.org/members/publications/video_archive.php?id=5703 Sorry, this talk is accessible only to RSGB members, but in a few words... G8DOH runs the numbers to demonstrate that the -130dBc/Hz target for transmitted phase noise is necessary to avoid raising the noise floor of other stations many kilometres away, and also many tens to hundreds of kHz away across the band, whenever their high-gain beams happen to be pointed at each other. That calculation assumes the UK transmitter power limit of 400W PEP output. For the US power limit of 1500W output, keeping all other assumptions the same, the target for transmitted noise floor would need to be better than -135dBc/Hz. The older KSYN3 can still meet that more stringent target but the KSYN3A probably cannot. >-Original Message- >From: elecraft-boun...@mailman.qth.net [mailto:elecraft- >boun...@mailman.qth.net] On Behalf Of Don Wilhelm >Sent: 27 June 2018 14:23 >To: hawley, charles j jr; Charlie T >Cc: elecraft@mailman.qth.net >Subject: Re: [Elecraft] [K3] factory upgrade to K3(s) > >Chuck, > >A big reduction in receiver noise floor and a huge improvement in both >transmit and receive phase noise. It is like getting a new transceiver. > >If you are strictly a casual operator, those qualities may not be >important to you, but if you are a DX'er or a contester, or otherwise >operate in crowded band condition, those things should be important >to you. > >73, >Don W3FPR
Re: [Elecraft] Field Day Report
NR6TT/7, situated 1500 feet above Flaming Gorge in extreme northeastern Utah at 7700 feet, was plagued not primarily by the thunderstorm QRN, dead band conditions, or the incredible windstorm on Saturday night that undid a tautline hitch and knocked down our antenna, but by curious passers-by intrigued by the dipole hanging from two pine trees precariously close to the cliff's edge-- including the teacher from Spain touring the western states and who had bicycled up to the rim and who presented a wonderful opportunity to practice my Spanish; a ham we worked who lived ten miles away and just couldn't resist driving up to see what our operation looked like and then wanted to tell us about every trail, canyon, creek, overlook, lake, lightning-damaged tree and moose-viewing site within a ten mile radius of where we were; and the guy wearing a ten-gallon hat who almost made me jump out of my socks when he sneaked up behind me and suddenly shouted, "WHO YOU TALKING TO?!" All combi ned, we spent a good four hours of our Field Day talking to these and others... time well spent, we thought, showing (as the W1AW Field Day message said) that amateur radio is "alive and well". NR6TT/7 Al W6LX and 12-year-old Blaise Elecraft K2 and homebrew W7EL Optimized (2.4 W) Dipole antenna at 1500 feet effective height __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Field Day rig experience
If you do take the icom, at 3.5A receive current drain you'd better take two extra batteries, too. Al W6LX >> Take the K3 , leave the IC-7610 at home. It’s to darn heavy to lug around. >> (19 lbs ) >>NS2N __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Boldly OT: 6 meter Sporadic-E season and the FT-8 microjuggernaut
I wrote an April Fool's article back in like 1999 (I might still be able to find it on dejanews) describing a make-believe ARRL contest which was totally automated; contesters could come home from work and peruse their logs to see what stations their computers had 'worked' that day. When parody becomes reality, it's no longer funny. I'm chagrined that that fictitious day appears to have finally arrived. FT8 is just a phase. It is the mode du jour, the next in a long parade of digital modes that stretches back to AMTOR and packet. This too, shall pass, to be replaced with the Next Big Mode, which in turn will pass and be replaced. In the meantime, there hasn't been a single CW signal in the morning on 40 meters so I can test out my new homebrew FD rig. It's very depressing. Al W6LX From: Wayne Burdick To: Elecraft Reflector Cc: "k...@yahoogroups.com" ; elecraft...@yahoogroups.com Sent: Friday, June 1, 2018 8:47 AM Subject: [Elecraft] Boldly OT: 6 meter Sporadic-E season and the FT-8 microjuggernaut At first I thought it was my receiver. Or my antenna farm, limited in scale by a pre-nuptial clause. Or noise caused by the zomboid army of switching power supplies oozing inexorably into my personal space. Nope. It turns out the dearth of CW and SSB signals on 6 meters at the height of 2018 Spring Sporadic-E season can be traced to one factor: the 24-hour intravenous rave that is FT-8. Yeah, I get the whole sub-noise-floor-and-not-automated-(wink)-QSO thing. But I’d like to figure out how those of us who enjoy the occasional gear-grinding manual-transmission contact can find each other on this brave new highway. Ideas? Wayne N6KR __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to alor...@sbcglobal.net __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] New to Elecraft and my experience
Contrast your experience, James, with what happened recently when I purchased a kit on eBay from a seller in a country that now has the NSA observing me closely for collusion. When I emailed to tell the seller that two critical parts were missing from the kit, he replied that that was "rubbish" and told me flat out I didn't know what I was doing. Can you imagine Elecraft ever doing that? I can't either. Al W6LX ___ Wish more companies were like this! 73 James KI0KN __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] When to use the preamp on the K3/K3S
Scott, If the weakest signals are already activating the AGC, that's the exact condition that leads to the many 'my K3 is noisy' complaints that we see here. Plus, that tends to make all signals sound like they're the same strength, another complaint we've heard in the past. In fact, you don't want weak signals activating AGC. You want strong signals, above a certain threshhold (AGC THR on the K3) to activate it. This gives you a nice, quiet linear region where weak signals sound weak, and stronger signals sound stronger. In addition, overload should not determine whether you turn off the preamp! That's way bad advice. Here's the general principle: you should only use as much gain as you need. AF as well as RF. Less is usually better. Your ears will not be blown by reducing your receiver gain. R, Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3 Preamp 2
Hi, Barry, It's not the signals that determine whether you need a preamp, it's the noise level. A receiver should have enough gain to put its internal noise floor below the external, atmospheric noise floor, so that it doesn't become the limiting factor in hearing weak signals close to the noise. That's what makes a preamp necessary. Certainly, if your noise floor is lower than here in urban North America, there may be cases where a preamp does us no good, but is necessary for you. I think I once posted a case study here a while ago... but I would have to go searching for it. The numbers I used were definitely US-biased. Life for a ham here has become a really discouraging exercise in trying to copy signals below your neighbors' app-enabled pet massagers and internet-controlled wine coolers, all fed by those infernal switch-mode power supplies. My two neighbors' homes are really just enormous square wave-producing things. This is also why everybody you hear is running 1,000 watts or more. It's power inflation. The military spends millions on radar jamming equipment... when all they'd have to do is do whatever my neighbor Johnny is doing. He must have a phased array radar, arc-welding, barrage jamming plant next door. If you ever bring your rig over here on vacation, be sure to pack a 60 dB attenuator with it. R, Al W6LX From: Barry Simpson To: elecraft@mailman.qth.net Sent: Saturday, April 7, 2018 2:25 PM Subject: [Elecraft] K3 Preamp 2 I often see posts from US stations questioning the need for any preamp below 20m and just now challenging the need for preamp 2 on 10m. That may be all well and good in the land of the huge antennas and the thousands of big signals from the US and Europe but let me tell you that down here, when you are scratching around for weak signals on 10m and 12m, preamp 2 makes a world of difference. Barry Simpson VK2BJ. Sent from my iPad __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to alor...@sbcglobal.net __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] P3 vs LP-Pan / NaP3
>>> But who doesn't use a shack >>> computer these days? Me. Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] [OT] Measurement of Power
I re-named the thread as a courtesy to the members who don't want to read this. We're getting caught in a mathematical war between the linear and logarithmic worlds. ± 20% in Watts, is about ± 1 dB in log. 1 dB accuracy is plenty good enough for us, folks. Especially given that any impedance mismatch is a source of error that we typically can't eliminate. In addition, I have found that Bird is very conservative and typically beats this spec by a lot. And by the way, I thought the Bird spec was 5% of full scale. Where did 20% come from? Don't all rush out to sell your Birds. They're perfectly fine. Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] DMM Recommendations -- Fluke 179?
If we are to be consistent and follow advice from countless (delighted) Elecraft owners on this list, any buyer of test equipment like the DMM in question is going to ensure that the company will be easy to contact and work with and stand behind its product when necessary. Yes, many times I've thrown away twenty dollars here and there on cheap stuff, but I'm getting mighty tired of doing so. Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] [OT] The Ultimate List of Hobbies for Men
I found it mildly gratifying that our hobby is listed at #2 of these 75: https://www.artofmanliness.com/2016/01/25/the-ultimate-list-of-hobbies-for-men-75-ideas-for-your-free-time/ Certainly, climbing a tower, sticking your hands into the HV compartment of an amplifier, or emergency communication under adverse conditions would require a modicum of manliness. (Begging the pardon of the ladies among us.) Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Elecraft KX2 compared with the latest "Ultra Portable" (?)
Poor Wayne. No matter how he positions an Elecraft product, a prevailing response is, "Yeah, but Elecraft doesn't do A or B." As consumers, we have been perfectly conditioned to regard more as better. I mean, if Brand X has 'more' than Brand Y, we automatically declare Brand X the winner. Brand X covers more bands? It's better. Brand X has more ADC bits? It *must* be better! There's something to be said about *doing* something better, as opposed to simply *having* more, isn't there? Wayne touched on this when he pointed out the huge discrepancy in current drain between the two rigs. As you know, this is hugely important for any portable or solar-powered situation. It is a major reason why, just for instance, I could not for a moment consider the new Icom 7610 because of it's 3x current drain versus the K3. My station is solar-powered and I have to worry about this. So that's a primary consideration for me, regardless of how much 'more' the 7610 may have. Simply having more isn't necessarily better. I know that's counterintuitive, but only because of our consumer conditioning. Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] UHF connectors [was: Array Solutions Lightning Arrestor]
Excellent. Thank you, Alan. Data for this particular measurement are very difficult to find on the web -- of course it took an ex-HP guy to do it! Times Microwave (a manufacturer of coaxial cable) says 0.01 dB per UHF connector pair (PL-259-to-SO-239) at HF; I have seen other private measurements that estimate 0.02 dB; and now this data from N1AL. I usually take the greater of these, 0.02 dB, as a worst-case number. But Alan's measurements pretty much show that the loss at HF is almost too small to measure-- even if he had performed a full two-port cal. Even so, you might be surprised to see how quickly it can add up. Beginning at the transmitter output (or receiver input) it is not uncommon to find 20 or more UHF connections in the path to the antenna. Using the 0.02 dB worst-case figure, that's at least 0.4 dB, or 9% of your power. I wouldn't worry about that but I know there are folks on here that would be bothered by that. This, of course, is not counting loss in cables, filters, lightning arrestors, power meters, bulkheads, switches, antenna tuners, baluns, amplifier through-paths, transmission lines, etc. These can add another dB or more to the total and far outweigh any loss in UHF connectors. If you want to minimize losses, UHF connectors are the last thing you should worry about. I encourage you to do an analysis to determine your system efficiency. I recently did so and discovered that I have a worst-case loss (to the feedpoint up at the antenna) of 1 dB, which is 21% of my power. Gone. Forever. Whoosh! Al W6LX ___ - Type N -- UHF -- FREQ (MHz) TOTAL LOSS PER CONNECTOR TOTAL LOSS PER CONNECTOR 1.8 0 dB 0 dB 0 dB 0 dB 30 0 00 0 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] I would like to get in touch with...
... Icom owners who have received a technical response from the president and lead designer of Icom and/or sent in a photograph of their rig from overseas and had Icom service technicans troubleshoot it for them just from the photo. Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
