Re: [Elecraft] K3 Observations Digital Modes and SSB
On Feb 2, 2011, at 11:41 AM, Jim Brown wrote: > An important source of IMD (and harmonic distortion) is the sound card used > to generate the digital signal. In the case of the K3, it is definitely poor IMD from the transmitter, since my K3's transmit IMD was even worse when set to use the internal PSK-D generator. I have tested a direct sound card -to- sound card link (no RF in between) and got better than -80 dBc IMD from cocoaModem's PSK31 interface. Even cheap sound cards like the Griffin iMic are pretty good with IMD. More than you can say about their second harmonic distortion, however (at least on the input side). 73 Chen, W7AY __ 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] K3 Observations Digital Modes and SSB
On 2/2/2011 11:08 AM, Kok Chen wrote: > My own K3 will not do any better than -35 dB transmit IMD An important source of IMD (and harmonic distortion) is the sound card used to generate the digital signal. The sound cards in IBM T-series Thinkpads are better than average, but their distortion increases by 10dB as you get close to clip level, even without clipping. Reducing the output level by only 6dB reduces distortion by 10dB. Thus, my advice for setting up sound card levels is to first crank the output level up to the point where you just begin to hear distortion (or see it on a scope), then back it off by at least 6dB (half the voltage). Audio transformers can also be a source of IMD (and harmonic distortion), and that distortion increases dramatically if they are driven from a high impedance source, even at relatively low signal levels. The ideal way to drive an audio transformer is from a source having a very low output impedance. Adding resistors in series with the source is a very bad idea, and CAUSES the transformer to produce distortion. This was a problem with the line output in early production K3s. . It's OK to add a 10dB pad (resistive voltage divider) between a sound card and the rig (K3 or other) IF the pad has a low output impedance. That's easy to do -- simply use a low value for the output resistor. Most sound cards are designed to drive headphones to about 1 volt peak, with load impedances between 8 and 600 ohms, so a good 10 dB voltage divider would be something like 220 ohms in series and 68 ohms as the load, or 180 in series and 56 ohms as the load, or 150 ohms in series and 47 ohms as the load. This range of values won't overload the sound card, and will minimize any distortion produced by the input transformer in the K3. BTW -- the same sort of precautions should be taken with ANY input transformer, not only those used in the K3. Finally, one must also be careful not to overdrive the K3 with too much audio gain. Follow instructions in the manual carefully for this. Note that these precautions apply to ALL audio feeds to a ham rig, including all digital modes and voice playback for contesting. 73, Jim Brown 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
Re: [Elecraft] K3 Observations Digital Modes and SSB
On Feb 2, 2011, at 2/211:14 AM, gold...@charter.net wrote: > Thanks that now makes sense to me. However, than almost every signal > that I am looking at is outside of the two main carriers. Like little > spikes, I don't know how else to define it. You only see two clean rails (plus IMD rails) when the PSK31 signal is idling. When someone types, their PSK31 signal will produce other sidebands -- so you see that fuzzy signal on a waterfall. With enough trickery, you can measure 3rd order IMD even when a station is actively transmitting. But the best time to measure is when a station is idling. > The IMD Meter you mention looks like a good investment. An even better investment is the Elecraft Directional Coupler. You can then tap the output from the K3 and feed that into a second receiver that has a computer connected to the second receiver's sound card. Measuring IMD is not so good if you just use a short sense antenna. Best to tap off of a directional coupler. 73 Chen, W7AY __ 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] K3 Observations Digital Modes and SSB
Hi Kevin, Thanks that now makes sense to me. However, than almost every signal that I am looking at is outside of the two main carriers. Like little spikes, I don't know how else to define it. Is this not also a function of the filtering set up in the software that you would be using, which supports your statement its kind of like a S meter so take it with a grain of salt. I will have to set up a sked with some fellow K3 users to play with them sending some screen shots back and forth of the waterfall. The IMD Meter you mention looks like a good investment. Don KD8NNU On Wed, Feb 2, 2011 at 1:19 PM, R. Kevin Stover wrote: > Short of using something like the KK7UQ IMD meter the best way to know > how clean you signal is is to have the guy at the other end send you a > screen shot of your signal on his waterfall. > > If you use something like the IMD meter, the lower the number the > better. Your shooting for -25 or lower. > If you get a screen shot you want NO tracks outside of the two main > carriers. > Treat reported IMD numbers from others like S meter readings. The > quality of that number has a lot to do with the software they're using > and how strong your signal is. > > > > On Wed, 2 Feb 2011 12:47:44 -0500 (EST) > gold...@charter.net wrote: > >> Thank you for the post, however I am confused. >> >> However, maybe you can help me out with some target numbers. >> >> What is a good IMD report number and good SN number from a receiveing >> station and what are the numbers that state you are messing up the >> bands. Lots of contacts kick back and IMD and SN number, as I do >> with my macros. >> >> From my perspective, I can see a trace from someone else and with my >> filters easily work around it with the K3 no problem, but I can not >> tell if I am creating a problem with IMD products. >> >> I am trying to understand the best way to set up my radio, and when I >> look at the tables in the link, it tells me that keeping ACL at a >> maximum of 4 with maybe an ocassional ticke to 5 was the key to a >> clean signal with a K3 and output power did not matter. >> >> Also I have found that there are instances where I can hear DX with >> the filters tight and for me to respond I have to turn the power up >> to 80 to make contact. >> >> Additionally, I try and find an open spot between frequiences in use >> and observe to see if I am close to anyone before any TX of any >> kind. I am amaized but the amount of guys who run with the AFC >> turned on in their software and they are constantly drifting around >> and drift close to you and then would be offended that you are >> interferring with them. >> >> Anyway, as stated above, my only feedback on my signal is when >> someone provides the IMD and SN report, so target numbers would be >> appreciated as we all have to share the space and contacts. >> >> Thanks in advance for your help. >> >> Don >> KD8NNU > > > > > -- > R. Kevin Stover > AC0H __ 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] K3 Observations Digital Modes and SSB
On Feb 2, 2011, at 2/29:47 AM, gold...@charter.net wrote: > What is a good IMD report number and good SN number from a > receiveing station and what are the numbers that state you are > messing up the bands. The transmit IMD that you see bandied about are 3rd order IMD numbers. If you take a look at a PSK31 signal that is idling (i.e., sending the Idle Varicode), you should see two carriers that are space 31.25 Hz apart. Third order IMD will therefore create an extra pair of sidebands. One that is 31.25 Hz away from the lower carrier and one that is 31.25 Hz away from the upper carrier. Like CW and RTTY keyclicks, these are not useful and only uses more spectrum that you need to pass information. The reason the idling PSK31 signal looks like two carriers idle signal is that it in not just phase modulated. There is also a cosinusoidal amplitude component. I had attempted to describe it a little when I wrote the PSK31 section in Chapter 16 of the 2010 ARRL Handbook. (For old timers, think "double sideband suppressed carrier" signals. There too, you have the same thing -- two carriers on the RF spectrum when you transmit a single audio tone DSB signal.) The existence of 3rd order IMD will just take up more spectrum space, and if they are loud enough, will bother everybody trying to copy the signal that is next to yours. If you hard clip a PSK31 signal (as in using severe amounts of ALC), the cosinusoidal waveshape becomes a square wave. Severe clipping will cause around -11 to -13 dB IMD. But wait! If you do PSK31 for long enough, you probably have seen signals with even worse IMD. Careful look at those signals will show that they were not just clipping but there are overshoots in the square wave envelopes! I have seen IMD as bad as -9 dBc. I would prefer that the station transmits with 10 times more power but staying inside a PSK31 passband, than spreading their energy over the entire PSK sub-band! If the SNR of a station is much worse than 25 dB, and his IMD is -25 dBc, you will not visually see any extra "rails" on his signal. However, with sufficient integration, you can measure the IMD of a stable signal even below its SNR. In practice however, I don't trust those measurements. So, if someone tells you that they can barely copy you, I won't trust their IMD report. Very often, they are just reporting the noise amplitude where the IMD component would have been. Sometimes, it is their receiving chain that is producing the IMD! Personally, I consider -25 dBc IMD to be barely acceptable. It is something like transmitting an extra 1/2 watt signal on the sides of a 100 watt signal. Most stations that are properly adjusted will run between -25 dBc and -35 dBc IMD. You can find some stations with obviously experienced PSK31 operators who do much better than that. They are often both loud and clean. My own K3 will not do any better than -35 dB transmit IMD. In fact, this K3 produces around -30 dBc IMD if you use PSK-D at 5 watts; so you are much better off using DATA-A from a good software program. -30 dBc IMD is starting to fall into the "mediocre" range. With my FT-1000MP at 5 watts, I have gotten -40 dBc IMD reports. But you need to be loud at the receiving end for them to properly measure IMD that is that low -- the few times I got numbers that high were from a local station and with KH6 -- we have a pipeline from Portland to KH6 :-). A signal has to be really loud to reliably measure -40 dBc IMD. > I am trying to understand the best way to set up my radio, and when > I look at the tables in the link, it tells me that keeping ACL at a > maximum of 4 with maybe an ocassional ticke to 5 was the key to a > clean signal with a K3 and output power did not matter. The IMD numbers may be the same, but remember that you are referencing the IMD number to the carrier power. Transmitting a -20 dBc IMD signal will produce a 1 watt image when you run 100 watts, while it produces a 0.1 watt image when you run 10 watts. The reason IMD is important is that a 100 watt station with -40 dBc IMD will produce an extra intermodulation image that is only as strong as a 10 watt station with -30 dBc IMD. The other way of looking at it is that a station running 100 watts with -40 dBc IMD uses up no more spectrum (no matter how far in terrestrial distance you are from him) than if he reduced his power to 10 watts but his IMD has degraded to -30 dBc. 73 Chen, W7AY __ 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] K3 Observations Digital Modes and SSB
Short of using something like the KK7UQ IMD meter the best way to know how clean you signal is is to have the guy at the other end send you a screen shot of your signal on his waterfall. If you use something like the IMD meter, the lower the number the better. Your shooting for -25 or lower. If you get a screen shot you want NO tracks outside of the two main carriers. Treat reported IMD numbers from others like S meter readings. The quality of that number has a lot to do with the software they're using and how strong your signal is. On Wed, 2 Feb 2011 12:47:44 -0500 (EST) gold...@charter.net wrote: > Thank you for the post, however I am confused. > > However, maybe you can help me out with some target numbers. > > What is a good IMD report number and good SN number from a receiveing > station and what are the numbers that state you are messing up the > bands. Lots of contacts kick back and IMD and SN number, as I do > with my macros. > > From my perspective, I can see a trace from someone else and with my > filters easily work around it with the K3 no problem, but I can not > tell if I am creating a problem with IMD products. > > I am trying to understand the best way to set up my radio, and when I > look at the tables in the link, it tells me that keeping ACL at a > maximum of 4 with maybe an ocassional ticke to 5 was the key to a > clean signal with a K3 and output power did not matter. > > Also I have found that there are instances where I can hear DX with > the filters tight and for me to respond I have to turn the power up > to 80 to make contact. > > Additionally, I try and find an open spot between frequiences in use > and observe to see if I am close to anyone before any TX of any > kind. I am amaized but the amount of guys who run with the AFC > turned on in their software and they are constantly drifting around > and drift close to you and then would be offended that you are > interferring with them. > > Anyway, as stated above, my only feedback on my signal is when > someone provides the IMD and SN report, so target numbers would be > appreciated as we all have to share the space and contacts. > > Thanks in advance for your help. > > Don > KD8NNU -- R. Kevin Stover AC0H __ 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] K3 Observations Digital Modes and SSB
Thank you for the post, however I am confused. However, maybe you can help me out with some target numbers. What is a good IMD report number and good SN number from a receiveing station and what are the numbers that state you are messing up the bands. Lots of contacts kick back and IMD and SN number, as I do with my macros. From my perspective, I can see a trace from someone else and with my filters easily work around it with the K3 no problem, but I can not tell if I am creating a problem with IMD products. I am trying to understand the best way to set up my radio, and when I look at the tables in the link, it tells me that keeping ACL at a maximum of 4 with maybe an ocassional ticke to 5 was the key to a clean signal with a K3 and output power did not matter. Also I have found that there are instances where I can hear DX with the filters tight and for me to respond I have to turn the power up to 80 to make contact. Additionally, I try and find an open spot between frequiences in use and observe to see if I am close to anyone before any TX of any kind. I am amaized but the amount of guys who run with the AFC turned on in their software and they are constantly drifting around and drift close to you and then would be offended that you are interferring with them. Anyway, as stated above, my only feedback on my signal is when someone provides the IMD and SN report, so target numbers would be appreciated as we all have to share the space and contacts. Thanks in advance for your help. Don KD8NNU On Wed, Feb 2, 2011 at 12:13 PM, Kok Chen wrote: > On Feb 2, 2011, at 2/21:37 AM, Julian, G4ILO wrote: > >> The most important thing when using PSK modes is not how much power >> you are >> using, but that the signal is *clean*, with the minimum of IMD >> products. And >> that is why with a barefoot K3 or any other 100W radio you should >> not exceed >> about 40W output. > > I agree completely with Julian about this. PSK31 is a weak signal > mode when conditions are good. How much power you need to use depends > on the SNR of your signal at the receiving end. > > Think about it. A 3 dB difference in your signal can only affect the > blocking dynamic range of the receiver by 3 dB. But if your transmit > IMD is 6 dB worse (I have seen some "QRP" signals with -25 dBc IMD), > you are ruining the band for many more people than just your nearby > neighbors who have receivers with poor dynamic range. > > With the K3, there is no practical difference in transmit IMD between > using 20 watts and 50 watts. See the two tables halfway down this > page: > > http://homepage.mac.com/chen/Technical/K3/Digital/digital.html > > In practice, it is non-productive to run power once your SNR at the > receiver is over 0 dB in a 300 Hz noise bandwidth. When there is > multipath, PSK31 will not get through no matter how much power you > use. Even though RTTY is 3 dB less sensitive than PSK31 when > conditions are good, it can still get through even flutter if you have > a good SNR at the receiving end (i.e., transmit with more power). > PSK31 will not get through flutter no matter how much power you apply. > > 73 > Chen, W7AY > > > > > __ > 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 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] K3 Observations Digital Modes and SSB
On Feb 2, 2011, at 2/21:37 AM, Julian, G4ILO wrote: > The most important thing when using PSK modes is not how much power > you are > using, but that the signal is *clean*, with the minimum of IMD > products. And > that is why with a barefoot K3 or any other 100W radio you should > not exceed > about 40W output. I agree completely with Julian about this. PSK31 is a weak signal mode when conditions are good. How much power you need to use depends on the SNR of your signal at the receiving end. Think about it. A 3 dB difference in your signal can only affect the blocking dynamic range of the receiver by 3 dB. But if your transmit IMD is 6 dB worse (I have seen some "QRP" signals with -25 dBc IMD), you are ruining the band for many more people than just your nearby neighbors who have receivers with poor dynamic range. With the K3, there is no practical difference in transmit IMD between using 20 watts and 50 watts. See the two tables halfway down this page: http://homepage.mac.com/chen/Technical/K3/Digital/digital.html In practice, it is non-productive to run power once your SNR at the receiver is over 0 dB in a 300 Hz noise bandwidth. When there is multipath, PSK31 will not get through no matter how much power you use. Even though RTTY is 3 dB less sensitive than PSK31 when conditions are good, it can still get through even flutter if you have a good SNR at the receiving end (i.e., transmit with more power). PSK31 will not get through flutter no matter how much power you apply. 73 Chen, W7AY __ 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] K3 Observations Digital Modes and SSB
On 2/2/2011 4:37 AM, Julian, G4ILO wrote: > The reason it is necessary to run higher power when using RTTY is that it is > an antiquated mode designed before the advent of DSP and it requires a > stronger signal to produce good copy than PSK31. The reason it is OK to run > 100W of RTTY using a barefoot K3 is because RTTY is a constant amplitude FSK > mode and does not cause any IMD. You don't need a lot of power to run RTTY. In the fall of 2009 in one of the RTTY contests I worked all continents with an IC-703+ at 5W into (big) wire antennas... 73, Ross N4RP -- FCC Section 97.313(a) “At all times, an amateur station must use the minimum transmitter power necessary to carry out the desired communications.” __ 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] K3 Observations Digital Modes and SSB
I share what Julian wrote 100% . My question was only oriented to take care of my rig . k3 makes the difference, not only in rx ! I have a vertical multiband antenna that works fine but it's a vertical, however k3 let me to receive and decode even weak signals. In tx k3 has a clean and perfect modulation and keeping ALC settings as suggested I receive always perfect comments to my waterfall track. In the past, using another rig, comments were different. With the goal to keep an eye to modulation quality/clean, in a previous post I suggested to add to p3 (sleeping at tx time HI) the possibility to show during tx time info about wave form or whatever else useful. This, in my opinion, would help to optimize the rig settings and have the maximum without producing rubbish into the air not only when in PSK, isn't it ? 73 to everybody ! Giorgio -- View this message in context: http://elecraft.365791.n2.nabble.com/K3-Observations-Digital-Modes-and-SSB-tp5976035p5984224.html Sent from the [K3] mailing list archive at Nabble.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
Re: [Elecraft] K3 Observations Digital Modes and SSB
Many people object to the use of high power with PSK modes because many people operate within a small section of the band and a strong signal can make life difficult for other users. But the difference between 40W and 100W is only about 4dB, less than an S point, less than the difference between a good antenna and a so-so one and less than the typical variation in signal strength caused by QSB. If you are close (geographically) to someone else using PSK31 they are going to be strong whatever the power they are running. The most important thing when using PSK modes is not how much power you are using, but that the signal is *clean*, with the minimum of IMD products. And that is why with a barefoot K3 or any other 100W radio you should not exceed about 40W output. The K3 will certainly handle running 100W output without overheating. But you will not be a good neighbour to other users because the IMD will deteriorate substantiually as the power increases. If you had a KPA100 then I dare say you could run 100W output and be a better neighbour than someone running 40W with a barefoot rig. The reason it is necessary to run higher power when using RTTY is that it is an antiquated mode designed before the advent of DSP and it requires a stronger signal to produce good copy than PSK31. The reason it is OK to run 100W of RTTY using a barefoot K3 is because RTTY is a constant amplitude FSK mode and does not cause any IMD. Don Wilhelm-4 wrote: > > Giorgio, > > The safe power for the K3 is 100 watts. A operator using more than 20 > to 50 watts for PSK31 is IMHO a "band hog" - PSK31 operation at QRP > levels is quite common and should not be abused by those running high > power (even though many do it). > > OTOH, RTTY is different because many operators are running the full > legal limit, but I have worked several RTTY stations in a contest using > only 100 watts. > > - Julian, G4ILO. K2 #392 K3 #222. * G4ILO's Shack - http://www.g4ilo.com * KComm - http://www.g4ilo.com/kcomm.html * KTune - http://www.g4ilo.com/ktune.html -- View this message in context: http://elecraft.365791.n2.nabble.com/K3-Observations-Digital-Modes-and-SSB-tp5976035p5984101.html Sent from the [K3] mailing list archive at Nabble.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
Re: [Elecraft] K3 Observations Digital Modes and SSB
I meant "... if you had a KPA*500* you could drive it to 100W output and ..." - Julian, G4ILO. K2 #392 K3 #222. * G4ILO's Shack - http://www.g4ilo.com * KComm - http://www.g4ilo.com/kcomm.html * KTune - http://www.g4ilo.com/ktune.html -- View this message in context: http://elecraft.365791.n2.nabble.com/K3-Observations-Digital-Modes-and-SSB-tp5976035p5984107.html Sent from the [K3] mailing list archive at Nabble.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
Re: [Elecraft] K3 Observations Digital Modes and SSB
Thanks you all for clarification (fast and shape response as usualthat's wonderful)! 73 de Giorgio -- View this message in context: http://elecraft.365791.n2.nabble.com/K3-Observations-Digital-Modes-and-SSB-tp5976035p5983831.html Sent from the [K3] mailing list archive at Nabble.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
Re: [Elecraft] K3 Observations Digital Modes and SSB
Giorgio, The safe power for the K3 is 100 watts. A operator using more than 20 to 50 watts for PSK31 is IMHO a "band hog" - PSK31 operation at QRP levels is quite common and should not be abused by those running high power (even though many do it). OTOH, RTTY is different because many operators are running the full legal limit, but I have worked several RTTY stations in a contest using only 100 watts. 73, Don W3FPR On 2/1/2011 4:07 PM, ik1bxn wrote: > by the way I wonder, without having a certain indication to trust right > now, what should be the suggested maximum RF power in PSK and RTTY , without > taking the risk of stressing finals. Could you give me an indication ? > Normally I stay at 40-45 wI feel (or better I hope) that's ok > Many thanks in advance > 73 de Giorgio __ 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] K3 Observations Digital Modes and SSB
45 watts might not be so bad from Italy on PSK, and certainly wouldn't be on RTTY. 73, Don, WB5HAK __ 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] K3 Observations Digital Modes and SSB
PSK is a low power mode- 40-45 watts is overkill to say the least - 20-25 is even strong. QRPers run 5 watts or less quite successfully with PSK. Dan - KI4YZE -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of ik1bxn Sent: Tuesday, February 01, 2011 4:07 PM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] K3 Observations Digital Modes and SSB by the way I wonder, without having a certain indication to trust right now, what should be the suggested maximum RF power in PSK and RTTY , without taking the risk of stressing finals. Could you give me an indication ? Normally I stay at 40-45 wI feel (or better I hope) that's ok Many thanks in advance 73 de Giorgio -- View this message in context: http://elecraft.365791.n2.nabble.com/K3-Observations-Digital-Modes-and-S SB-tp5976035p5982666.html Sent from the [K3] mailing list archive at Nabble.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 __ 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] K3 Observations Digital Modes and SSB
by the way I wonder, without having a certain indication to trust right now, what should be the suggested maximum RF power in PSK and RTTY , without taking the risk of stressing finals. Could you give me an indication ? Normally I stay at 40-45 wI feel (or better I hope) that's ok Many thanks in advance 73 de Giorgio -- View this message in context: http://elecraft.365791.n2.nabble.com/K3-Observations-Digital-Modes-and-SSB-tp5976035p5982666.html Sent from the [K3] mailing list archive at Nabble.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
Re: [Elecraft] K3 Observations Digital Modes and SSB
Don, Thanks for your fine compliments. I do have a good memory for those kind of things, and will do a perusal of the .pdf version of the manual when required. I do what I can to help others. When I started my ham radio adventures as a teen, I had a whole radio club in a small town (about 20 members - town population was about 5000) who helped me along and tried to set me on a proper path to not only ham radio, but to a satisfying career in electrical engineering. Most of them are gone now, and I cannot thank them directly, but they shared their knowledge with me, and I pass along what I can in hopes of helping others the way they helped me. BTW: The East Palestine (Ohio) radio club has been continuously active for over 50 years. If you hear W8GMM on the air, that is the one. I believe that remains one of the greater ham licenses per capita than for any other area. 73, Don W3FPR On 1/30/2011 10:02 PM, gold...@charter.net wrote: > Don, > > How do you know so much detail, did you help design these things? :-) > > You always have help for everyone to make our experience even better so > thank you very much!!! > > Don > KD8NNU > __ 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] K3 Observations Digital Modes and SSB
Don, How do you know so much detail, did you help design these things? :-) You always have help for everyone to make our experience even better so thank you very much!!! Don KD8NNU On Sun, Jan 30, 2011 at 9:56 PM, Don Wilhelm wrote: > Don, > > You are doing it right - except -- > > Crank up either the K3 line-in gain or the computer audio line-out a > bit more - the proper setting is to have 4 "ALC" bars on solid and the > 5th one flickering. I put "ALC" in quotes, because the K3 ALC meter > is like a VU meter for the first 4 bars. The onset of ALC is > indicated by the 5th bar. > > 73, > Don W3FPR > > On 1/30/2011 9:45 PM, gold...@charter.net wrote: >> Finally I learned really dial in my output from the pc for the >> digital >> modes so that the ALC would be at a solid 3 bars and just tickel the >> 4th >> bar. In this condition I could go to 100w out and still have a clean >> signal. I was able to punch some dx at high power that i could not >> get >> at 50w or less. >> __ 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] K3 Observations Digital Modes and SSB
Don, You are doing it right - except -- Crank up either the K3 line-in gain or the computer audio line-out a bit more - the proper setting is to have 4 "ALC" bars on solid and the 5th one flickering. I put "ALC" in quotes, because the K3 ALC meter is like a VU meter for the first 4 bars. The onset of ALC is indicated by the 5th bar. 73, Don W3FPR On 1/30/2011 9:45 PM, gold...@charter.net wrote: > Finally I learned really dial in my output from the pc for the digital > modes so that the ALC would be at a solid 3 bars and just tickel the 4th > bar. In this condition I could go to 100w out and still have a clean > signal. I was able to punch some dx at high power that i could not get > at 50w or less. > __ 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
