Re: [Elecraft] K2 ATU
Skip, If you need additional trials for tuning with the KAT2, set the ATU menu to ALT. 73, Don W3FPR On 7/10/2018 9:53 PM, Fred Jensen wrote: Does the K2 ATU maybe find a better match if you to TUNE again quickly, or is the first match the bestest it can do? __ 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] K2 ATU
Does the K2 ATU maybe find a better match if you to TUNE again quickly, or is the first match the bestest it can do? 73, Fred ["Skip"] K6DGW Sparks NV DM09dn Washoe County __ 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 + ATU + Loop antenna in the attic
Don, The fan antenna was a lashup in the attic in hopes of having another antenna, hopefully to use with the K2 upstairs in the office. If it worked out, great; if not, no big deal. The attic isn't easy to get into (no pull-down), and not a lot of room to stumble around up there. The final solution was to switch my 130' Carolina Windom between the K2 and K3. See bottom of http://wilcoxengineering.com/projects/amateur-projects/39-fan-dipole . The coax relay didn't make good contact, so I replaced it with a big 24 vdc 4PDT junk relay in a metal box: the extra contacts give solid connections AND ground the unused feed to either the K2 or K3. BTW, only one rig is ever physically connected to the coax unless it's powered up and being used. With the storms ripping around today, both the K2 and K3 are safely disconnected! Cheers, Alan Alan D. Wilcox, W3DVX (K2-5373, K3-40) 570-321-1516 http://WilcoxEngineering.com http://eBookEditor.net https://www.smashwords.com/books/view/28062?ref=awilcox Williamsport, PA 17701 On 4/15/11 7:29 PM, Don Wilhelm wrote: > Alan, > > Sorry to hear about your lack of success with the fan dipoles. I have > three of them - one for 80 and 40, another for 30, 17 and 12m, and yet > another for 20, 15, and 10. They work very well. > > My "secrets" - space the wires for each band away from one another - > my 80 and 40 antennas are at right angles to each other, so there is > little of any interaction. The other two have the wires spaced about > 1 foot apart using CPVC pipe with holes drilled in them (wires through > the holes) to maintain the spacing. PVC would work too, but is heavier). > > The antennas do interact, so plan ahead, you will have to do some "cut > and try" pruning. Tune the lowest band or resonance first, and then > the next band higher in frequency. Trying it the other "way 'round" > is an exercise in futility (been there, done that, and have the scars). > > I usually consider 3 bands on one feedline the limit of my patience, > but this last weekend I helped a friend construct an antenna with 4 > wires - 80, 40, 20, and 10 meters. It was a bit of a pain to tune, > but it worked out well. Cut the wires at least 10% long and prune as > required. > > One other point - do not use separate wires for bands that are close > to the 3rd harmonic of another band - in other words, for HF, do not > put a 30 meter radiator on a feedline that contains an 80 meter wire, > and do not put a 15 meter wire on a feedline that also has a 40 meter > wire. The lower band antenna may be usable on the 3rd harmonic > (likely with a tuner), but trying to combine those two wires will > result in even more frustration. > > 73, > Don W3FPR > > On 4/15/2011 6:15 PM, Alan D. Wilcox wrote: >> FWIW, see my fan antenna at >> http://wilcoxengineering.com/projects/amateur-projects/39-fan-dipole >> A bright idea that didn't work out so well! >> >> Cheers, Alan >> >> Alan D. Wilcox, W3DVX (K2-5373, K3-40) >> > __ 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] K2 + ATU + Loop antenna in the attic
On Fri, Apr 15, 2011 at 7:16 PM, Ron D'Eau Claire wrote: > the efficiency, ease and simplicity of a doublet* > fed with open wire line... > > > Ron is so right. At the risk of re-re-repeating myself, whether or not an antenna is resonant, or matches coax, has nothing to do with its effectiveness as a radiator or receiver of signals. You don't have to feed it with coax. If you can put up an antenna with multiple radiators or traps or matching sections, you can put up a single antenna with no traps and no matching sections, feed it with ladder line or window line (or even twin lead), and get equal (or usually better) results. I guess guys like coax-fed antennas because they see that SO239 on the back of the rig, but it doesn't have to go any farther than a balun at the shack exit. Enough RF is wasted every day in long lossy runs of coax to power a year's worth of DXpeditions. Tony KT0NY __ 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] K2 + ATU + Loop antenna in the attic
That's a sign the dipole is significantly unbalanced or you have common mode signals getting into the receiver. The balun is supposed to take care of the common mode suppression, but that often depends upon the impedance it sees, which varies widely in a "tuned feeder" system. A truly balanced line won't pick up RF or radiate significantly. OTOH, it could be that your dipole itself is simply closer to the house and noise than the vertical. BTW, every foot of coax in a system with high SWR costs you dearly in RF losses. Ron AC7AC -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On ...Currently my most often used antenna is a dipole fed with ladder line. The ladder line connects to a balun and a short piece of coax to the radio with built in tuner. This setup tunes well but seems to pick up noise from the house. I should probably use more coax to get the ladder line a bit away from the house. 73 - Mike WA8BXN __ 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] K2 + ATU + Loop antenna in the attic
I have had two fan dipole in use maybe 15-20 years ago, before the time of widespread use of auto tuners. One was a commercial model, with the various lengths of wire on each side of the center insulator spaced about an inch apart (spacers were used). I did not have so much success with it. The other was homebrew, with 3 dipoles sharing the same center insulator and coax, but each going in different directions with the trees available. It was a great antenna that gave me good performance with low swr on my bands of interest without need for a tuner. Currently my most often used antenna is a dipole fed with ladder line. The ladder line connects to a balun and a short piece of coax to the radio with built in tuner. This setup tunes well but seems to pick up noise from the house. I should probably use more coax to get the ladder line a bit away from the house. I also have a vertical with decent radial system, coax fed, a fair distance from the house (>100 feet) that picks up much less noise from the house. I do think the dipole works better than the vertical, at least for transmitting. 73 - Mike WA8BXN __ 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] K2 + ATU + Loop antenna in the attic
I have an array of dipoles, some trapped, some using W9INN style chokes. I also have a tribander. But the antenna that gets used all the time is 160' doublet fed with 300 ohm line which goes into a DX Engineering 1:1 balun with short piece of RG-8 type coax coming into the house. The tuners on the K1, K2, and K3 will tune it to any band. I have experimented a great deal with fan dipoles. They certainly work. And also Off-Center fed antennas; they also work well. Loops a good too. I have a notebook with 40 years of wire antenna experiments. For me the most satisfying antenna so far is the simple doublet. It will always be the first antenna I recommend. With the great tuners in the Elecraft gear, it seems like a no-brainer. 73, Doug -- K0DXV On 4/15/2011 6:16 PM, Ron D'Eau Claire wrote: > I played with a fan dipole back in the 1960's, and played and played and > played trying to get a decent (less than 3:1) match to 50 ohm coax. Never > was happy. > > That experiment taught me the efficiency, ease and simplicity of a doublet* > fed with open wire line. Working out the process of getting the open wire > line into the shack wasn't nearly as difficult as trying to get the antenna > to present a decent match to the coax, and it was a wonderfully efficient > and effective all band antenna mounted at an "inverted V" with the apex at > 50 feet. > > BTW, my doublet was 100 feet end-to-end and worked beautifully on 160 > through 10 meters. Granted, at so close to the ground the radiation was > mostly straight up on 160 but on that band I was mostly interested in > working locals out to 100 miles or so. We had a lot of mobiles active on 160 > back then as well as fixed stations. And none of the rude nonsense so often > found on 75. > > Ron AC7AC > > *Wire fed at the center but not necessarily a "dipole" - i.e. 1/2 wavelength > long - on any band. > > -Original Message- > Subject: Re: [Elecraft] K2 + ATU + Loop antenna in the attic > >Alan, > > Sorry to hear about your lack of success with the fan dipoles. I have > three of them - one for 80 and 40, another for 30, 17 and 12m, and yet > another for 20, 15, and 10. They work very well. > > My "secrets" - space the wires for each band away from one another - my > 80 and 40 antennas are at right angles to each other, so there is little > of any interaction. The other two have the wires spaced about 1 foot > apart using CPVC pipe with holes drilled in them (wires through the > holes) to maintain the spacing. PVC would work too, but is heavier). > > The antennas do interact, so plan ahead, you will have to do some "cut > and try" pruning. Tune the lowest band or resonance first, and then the > next band higher in frequency. Trying it the other "way 'round" is an > exercise in futility (been there, done that, and have the scars). > > I usually consider 3 bands on one feedline the limit of my patience, but > this last weekend I helped a friend construct an antenna with 4 wires - > 80, 40, 20, and 10 meters. It was a bit of a pain to tune, but it > worked out well. Cut the wires at least 10% long and prune as required. > > One other point - do not use separate wires for bands that are close to > the 3rd harmonic of another band - in other words, for HF, do not put a > 30 meter radiator on a feedline that contains an 80 meter wire, and do > not put a 15 meter wire on a feedline that also has a 40 meter wire. > The lower band antenna may be usable on the 3rd harmonic (likely with a > tuner), but trying to combine those two wires will result in even more > frustration. > > 73, > Don W3FPR > > On 4/15/2011 6:15 PM, Alan D. Wilcox wrote: >> FWIW, see my fan antenna at >> http://wilcoxengineering.com/projects/amateur-projects/39-fan-dipole >> A bright idea that didn't work out so well! >> >> Cheers, Alan >> >> Alan D. Wilcox, W3DVX (K2-5373, K3-40) >> > __ > 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 > __ 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] K2 + ATU + Loop antenna in the attic
I played with a fan dipole back in the 1960's, and played and played and played trying to get a decent (less than 3:1) match to 50 ohm coax. Never was happy. That experiment taught me the efficiency, ease and simplicity of a doublet* fed with open wire line. Working out the process of getting the open wire line into the shack wasn't nearly as difficult as trying to get the antenna to present a decent match to the coax, and it was a wonderfully efficient and effective all band antenna mounted at an "inverted V" with the apex at 50 feet. BTW, my doublet was 100 feet end-to-end and worked beautifully on 160 through 10 meters. Granted, at so close to the ground the radiation was mostly straight up on 160 but on that band I was mostly interested in working locals out to 100 miles or so. We had a lot of mobiles active on 160 back then as well as fixed stations. And none of the rude nonsense so often found on 75. Ron AC7AC *Wire fed at the center but not necessarily a "dipole" - i.e. 1/2 wavelength long - on any band. -Original Message----- Subject: Re: [Elecraft] K2 + ATU + Loop antenna in the attic Alan, Sorry to hear about your lack of success with the fan dipoles. I have three of them - one for 80 and 40, another for 30, 17 and 12m, and yet another for 20, 15, and 10. They work very well. My "secrets" - space the wires for each band away from one another - my 80 and 40 antennas are at right angles to each other, so there is little of any interaction. The other two have the wires spaced about 1 foot apart using CPVC pipe with holes drilled in them (wires through the holes) to maintain the spacing. PVC would work too, but is heavier). The antennas do interact, so plan ahead, you will have to do some "cut and try" pruning. Tune the lowest band or resonance first, and then the next band higher in frequency. Trying it the other "way 'round" is an exercise in futility (been there, done that, and have the scars). I usually consider 3 bands on one feedline the limit of my patience, but this last weekend I helped a friend construct an antenna with 4 wires - 80, 40, 20, and 10 meters. It was a bit of a pain to tune, but it worked out well. Cut the wires at least 10% long and prune as required. One other point - do not use separate wires for bands that are close to the 3rd harmonic of another band - in other words, for HF, do not put a 30 meter radiator on a feedline that contains an 80 meter wire, and do not put a 15 meter wire on a feedline that also has a 40 meter wire. The lower band antenna may be usable on the 3rd harmonic (likely with a tuner), but trying to combine those two wires will result in even more frustration. 73, Don W3FPR On 4/15/2011 6:15 PM, Alan D. Wilcox wrote: > FWIW, see my fan antenna at > http://wilcoxengineering.com/projects/amateur-projects/39-fan-dipole > A bright idea that didn't work out so well! > > Cheers, Alan > > Alan D. Wilcox, W3DVX (K2-5373, K3-40) > __ 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] K2 + ATU + Loop antenna in the attic
Alan, Sorry to hear about your lack of success with the fan dipoles. I have three of them - one for 80 and 40, another for 30, 17 and 12m, and yet another for 20, 15, and 10. They work very well. My "secrets" - space the wires for each band away from one another - my 80 and 40 antennas are at right angles to each other, so there is little of any interaction. The other two have the wires spaced about 1 foot apart using CPVC pipe with holes drilled in them (wires through the holes) to maintain the spacing. PVC would work too, but is heavier). The antennas do interact, so plan ahead, you will have to do some "cut and try" pruning. Tune the lowest band or resonance first, and then the next band higher in frequency. Trying it the other "way 'round" is an exercise in futility (been there, done that, and have the scars). I usually consider 3 bands on one feedline the limit of my patience, but this last weekend I helped a friend construct an antenna with 4 wires - 80, 40, 20, and 10 meters. It was a bit of a pain to tune, but it worked out well. Cut the wires at least 10% long and prune as required. One other point - do not use separate wires for bands that are close to the 3rd harmonic of another band - in other words, for HF, do not put a 30 meter radiator on a feedline that contains an 80 meter wire, and do not put a 15 meter wire on a feedline that also has a 40 meter wire. The lower band antenna may be usable on the 3rd harmonic (likely with a tuner), but trying to combine those two wires will result in even more frustration. 73, Don W3FPR On 4/15/2011 6:15 PM, Alan D. Wilcox wrote: > FWIW, see my fan antenna at > http://wilcoxengineering.com/projects/amateur-projects/39-fan-dipole > A bright idea that didn't work out so well! > > Cheers, Alan > > Alan D. Wilcox, W3DVX (K2-5373, K3-40) > __ 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] K2 + ATU + Loop antenna in the attic
On 4/15/2011 3:15 PM, Alan D. Wilcox wrote: > FWIW, see my fan antenna at > http://wilcoxengineering.com/projects/amateur-projects/39-fan-dipole > A bright idea that didn't work out so well! If I had a dollar for every "Gee, it seemed like a good idea at the time" situation I've found myself in, I'd have a LOT more radio equipment. 73, Fred K6DGW - Northern California Contest Club - CU in the 2011 Cal QSO Party 1-2 Oct 2011 - www.cqp.org __ 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] K2 + ATU + Loop antenna in the attic
FWIW, see my fan antenna at http://wilcoxengineering.com/projects/amateur-projects/39-fan-dipole A bright idea that didn't work out so well! Cheers, Alan Alan D. Wilcox, W3DVX (K2-5373, K3-40) 570-321-1516 http://WilcoxEngineering.com http://eBookEditor.net https://www.smashwords.com/books/view/28062?ref=awilcox Williamsport, PA 17701 On 4/15/11 1:08 PM, Wayne Conrad wrote: > On 04/11/2011 04:11 PM, Wayne Conrad wrote: >> My radio (K2 with the internal ATU) hasn't shipped yet, but that >> shouldn't stop me from putting up an antenna, right? If only I knew >> what to put up, that is. That's where I'm asking for help. >> (snip) >> > Thank you to everyone who replied, both publicly and privately. Your > responses were great. Most of you urged me to put the antenna outside. > As Fred Jensen said, "Even something laid over the roof will probably > work better for you". So, outside it will be. I also got several > requests that I put in a proper safety ground no matter where my antenna > is, so I will do that, too. > > Best Regards, > Wayne Conrad > > __ > 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] K2 + ATU + Loop antenna in the attic
On 04/11/2011 04:11 PM, Wayne Conrad wrote: > My radio (K2 with the internal ATU) hasn't shipped yet, but that > shouldn't stop me from putting up an antenna, right? If only I knew > what to put up, that is. That's where I'm asking for help. > (snip) > Thank you to everyone who replied, both publicly and privately. Your responses were great. Most of you urged me to put the antenna outside. As Fred Jensen said, "Even something laid over the roof will probably work better for you". So, outside it will be. I also got several requests that I put in a proper safety ground no matter where my antenna is, so I will do that, too. Best Regards, Wayne Conrad __ 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] K2 + ATU + Loop antenna in the attic
Wayne : You got some good advice so far. I am in agreement that an outside antenna will perform better than one in the attic but you can always start with an attic antenna and add an outdoor antenna later. An attic antenna makes a great backup antenna as it will not succumb to severe weather (i.e icing, wind etc). As some have suggested, instead of a loop you could put up a doublet (ie dipole). The advantage will be that it may be easier to match on a lower bands. If you run the wire diagonally across the attic and then bend the ends in to form a Z shape you can probably get more wire up and that will help. Best of luck Michael VE3WMB __ 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] K2 + ATU + Loop antenna in the attic
Wayne, If you have no choice and have to use an antenna in the attic placed close to the rafters, I would suggest that you do use iinsulators to prevent any part of the antenna touching a rafter. A fire risk could exist if the antenna's wire is simply laid on the rafters, especially if using higher power on several bands. Welcome to the hobby, and have fun!! 73, Geoff GM4ESD (Licensed 1946) On April 12, 2011 at 12:11 AM, Wayne Conrad wrote: > I don't know whether I need to keep the antenna wire off of the rafters > with insulators, or can I just let it lay there. Nor do I know if the > answer to that question changes if I eventually go QRO. __ 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] K2 + ATU + Loop antenna in the attic
On Mon, Apr 11, 2011 at 7:11 PM, Wayne Conrad wrote: > I want to start out with an loop antenna in the attic, etc Wayne, you've already gotten some pretty good advice on this subject. May I add my two cents' worth here? First, you did not make it clear at all if your attic antenna is a 'must' due to CC&Rs or simply your "choice". Wayne, if you have any choice in the matter, put the antenna outside. I have no choice due to CC&Rs so my antenna has been in my attic for the past nine years since we moved into this townhouse. Second, lightning,'close strikes', and static build-up can wipe out your investment in hardware just as easily in the attic as can happen outside. I happen to know this because a Hallicrafters SX-146 practically blew up in my face several years ago. Take the necessary precautions, please! Third, how successful your attic installation will be largely depends upon the particulars of YOUR situation. Some issues can be mitigated; some cannot. Assess your attic environment and if the list of "negatives" outweighs the "positives" then you might want to start investigating some sort of outside 'stealth' setup. In my case, I found my attic to be quite RF friendly. There is no metalized insulation up there, the vents are all PVC, all wiring is below the attic floor, there is no HVAC at all, tthe shingles are asphalt, the ice dam is non-metallic, the gutter runs are extremely short (due to the architecture) and the downspouts are 90 degrees off from my antenna plane and much lower. There were two runs of "slinky-like" 4" bathroom vent hose. I went up and chopped them up into small segments and then put them back together again with duct tape. These are a few things you might want to check out in your attic. Fourth, I run only QRP with my attic antenna. Technically, I can meet the MPE Uncontrolled limits at 100 watts but I prefer not to run higher power. Above a nominal 30 watts I turned on my neighbor's carbon monoxide detector, put my CW signals into her telephone, and turned my own DVD player on and off, on and off. The CO problem was "unfixable" and probably due to the unit's design. The phone problem was solved with the addition of a filter from KY Filters. The DVD problem was solved with a single Mix 43 toroid on the DVD player's line cord. For your information, the antenna I chose to install in my attic is a homebrewed 62' doublet bent a couple times to fix the space available. I avoided doubling it back on itself. The center insulator is the Delta-C surge supressor from Alpha-Delta. I fed it with 14 feet of 450 ohm ladder line directly to an SGC-237 autocoupler on a shelf near the ceiling in a linen closet right below the feedpoint. This keeps the rather expensive autocoupler out of the winter's cold and the summer's heat in the attic. The run from the autocoupler to my station is about 25 feet of RG8X. I have a copper cold water pipe behind my operating desk and I confirmed that it is tied into the electrical panel as per code here in NY. The ground is *not required* in the sense that the doublet is already balanced but it's good practice and I use it. I'm working "the world" on 5 watts, frequently much less, and having all the fun I can handle. I can load up 160 through 6 meters with the doublet. My SWRs are all below 1.4:1 except for 40 meters where I am 1.8. I may need to shorten/lengthen the ladder line somewhat. I guess the message is simply this - evaluate your environment, consider the options, and then go for it. Electromagnetic particles can't read textbooks so they don't often realize that they are not supposed to propagate themselves to the far corners of the world from a measly attic antenna hi! Good luck with your loop! It may surprise you! 73, Stan WB2LQF KX1 #2411K1#2994K2# 6980K3#5244 K9 #1 (Cocoa the Chihuahua) Everything is QRP, even the dog. You seem set on a loop. They work and they work well. __ 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] K2 + ATU + Loop antenna in the attic
Wayne, like many members of this list, I've been right in your shoes. Like the previous posters, I'd recommend getting your wire outside. Here's a specific recommendation: While waiting for your radio to come, build a 4:1 unun. Here's a website with instructions: http://www.pcsystems-ss.co.uk/g7lrrweb/index.php?module=pagemaster&PAGE_user_op=view_page&PAGE_id=52&MMN_position=77:37 I'm guessing you're on an upstairs floor, but that's okay. Run coax from your rig to the unun. Then run a single wire out the window to the farthest, highest tree limb you can reach (see below). This goes to the "hot" side of the unun. For the cold side, make a counterpoise. Cut three or more wires in various lengths from 10' to about 30' and drape them out the window, in the gutters, on the garage roof, or whatever. The counterpoise will be your RF ground, but you also need a good DC ground. There's plenty of info on this reflector about that. With the right counterpoise and a properly-built unun, your ATU will match the wire perfectly on all the bands for which it's long enough, and you won't have any RF in the shack. To get a wire in the tree, you can use various gizmos. I rigged up a slingshot to shoot a weight which pulls fishing mono from a spinning reel. This will get a line up about 40 - 50 feet. See radioworks.com for some advice on shooting lines into trees. This setup sounds a bit hokey, but it works. If your wire is long enough, it will even provide gain over a dipole. I am just one of many who have used such an arrangement for lots of DX exploits. For example, my barefoot K3 worked 100 countries in 100 QSOs in 24 hours last month; I also have 40 zones, 300 countries, etc. etc. This is not to say that it is better than a 3-element wide-spaced Yagi, but it's a hell of a lot better than a wire in the attic. 73, Tony KT0NY __ 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] K2 + ATU + Loop antenna in the attic
A loop in the attic is asking for coupling to all those nearby conductors. They will do the following: 1) Capture and dissipate your precious RF. No-one will hear you. 2) Couple large amounts of electrical noise into your receiver. You will hear nobody. 3) Pick up even QRP levels of RF and funnel it into electronic devices in your house. The best choice is to put up a balanced 'doublet' or dipole outside. It won't be more expensive than a loop in the attic. If you MUST put it in the attic, I still recommend a doublet. It will couple to the wires, etc. but not as badly as a loop, which may exhibit magnetic coupling to nearby loops of wire. My guess is that lightning is as likely to hit a wire in the attic as one just above it but outside! But the more likely problem with lightning is damage to the radio from voltages induced from nearby strokes. You should make sure to have an arrangement to dissipate static charges on whatever antenna you choose, indoor or outdoor. On 4/11/2011 4:11 PM, Wayne Conrad wrote: > My radio (K2 with the internal ATU) hasn't shipped yet, but that > shouldn't stop me from putting up an antenna, right? If only I knew > what to put up, that is. That's where I'm asking for help. > > I want to start out with an loop antenna in the attic. Why loop? Mostly > the very American idea that more wire must be better, plus it's > balanced--I hope to not need a separate RF ground, or counterpoises, or > any of that jazz). Why the attic? So I don't have to worry about > lightning protection, and because it ought to be incredibly cheap to put > up. I've spent every dime I have on the radio, you see. > > The house is the usual ~60' x ~30 feet and "L" shaped, single story, and > the major axis is North/South. The attic is full of trusses and > fiberglass, but I can get to most of it, sometimes slithering on my > belly like a snake. There are the usual electrical wires, network > cabling (OK, maybe not everyone has CAT6 in their attic), TV coax, and > AC ducts going hither and thither. My shingles are asphault. > > I have no idea what band or bands I'll be on. I don't even have my > license yet. > > My thought is that I run the loop around the perimeter of the attic, as > close to the eaves as possible. Over the radio bench, I'll punch a hole > in the ceiling and drop feedline down the wall. > > I was thinking of open-wire feeder, because I "read on the internet" > that it might be better for this application. > > It occurs to me that I could omit the 4' of feedline and just drop the > two wires down. Using the self-adhesive conduit that the hardware store > sells, I could keep those two wires at "an appropriate distance" from > each other, and white conduit looks better against a white wall than a > black cable. I don't know if that's a good idea, or what "an > appropriate distance" would be. > > I don't know if I need a balun, or even what kind. > > I don't know whether I need to keep the antenna wire off of the rafters > with insulators, or can I just let it lay there. Nor do I know if the > answer to that question changes if I eventually go QRO. > > I don't know if the length of the loop matters. > > As you can tell, the ratio of things I know to things I don't know is > pretty small. Can you please help me improve that ratio? > > Thanks, and best regards, > Wayne Conrad > __ > 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 -- Vic, K2VCO Fresno CA http://www.qsl.net/k2vco/ __ 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] K2 + ATU + Loop antenna in the attic
On 4/11/2011 4:11 PM, Wayne Conrad wrote: > I want to start out with an loop antenna in the attic. Why loop? Mostly > the very American idea that more wire must be better, plus it's > balanced--I hope to not need a separate RF ground, or counterpoises, or > any of that jazz). You need a safety ground on your radio, a loop antenna does not normally care about ground, except in what ground does to the radiation elevation angle. > Why the attic? So I don't have to worry about > lightning protection, and because it ought to be incredibly cheap to put > up. I've spent every dime I have on the radio, you see. Is it the K2/10? Anything outside will be better. Trees? Even something laid over the roof will probably work better for you. > > I have no idea what band or bands I'll be on. I don't even have my > license yet. That will be a necessity :-) > > My thought is that I run the loop around the perimeter of the attic, as > close to the eaves as possible. Over the radio bench, I'll punch a hole > in the ceiling and drop feedline down the wall. Elevating the wire above the ceiling joists might help some. Many of the "Attic Designs" that have been published seem to use the "open space" of the attic rather than out near the eaves. > > I was thinking of open-wire feeder, because I "read on the internet" > that it might be better for this application. A balun is probably going to be important, the K2 output is inherently unbalanced. Since you will have the ATU, putting the balun at the radio will eliminate any losses on the coax. > > It occurs to me that I could omit the 4' of feedline and just drop the > two wires down. Using the self-adhesive conduit that the hardware store > sells, I could keep those two wires at "an appropriate distance" from > each other, and white conduit looks better against a white wall than a > black cable. I don't know if that's a good idea, or what "an > appropriate distance" would be. 2 or 3 cm is probably just fine. > > I don't know if I need a balun, or even what kind. See above > > I don't know whether I need to keep the antenna wire off of the rafters > with insulators, or can I just let it lay there. That would be a good idea. Electric fence insulators are cheap and would work. Nor do I know if the > answer to that question changes if I eventually go QRO. I don't know what you mean by QRO, but if it is anything over 10 or so watts, with such an antenna, you will likely not like the results :-) You also need to do a radiation safety survey which you can find on the ARRL web site. > > I don't know if the length of the loop matters. Basically, you're just putting up some conductor and attempting to load power into it. It's a "more is better" situation. The KAT2 will stuff power into some pretty weird impedances, but not all possible weird ones. > > As you can tell, the ratio of things I know to things I don't know is > pretty small. Can you please help me improve that ratio? Hope this helps. Anything you can do outside will probably be better than anything you can do in the attic, unless you have CC&R's. __ 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] K2 + ATU + Loop antenna in the attic
Wayne, I understand your reasons for putting an antenna in the attic, but that will offer no additional lightning protection over putting it outside. An outside antenna will pick up more noise from the house wiring, so why go to the trouble. Even if you mount your loop antenna on short standoffs just above the roof (look for electric fence insulators if you want to do that, they work very well). it will work better than it will inside. Your idea of just bringing the ends of the wire loop into the shack using two pieces of conduit to maintain the spacing between the wires will work very well - you would be creating an open wire feedline, which is quite efficient. You will need a balun between the coaxial output from the tuner and any parallel transmission line. Use a current balun. Many use a 4:1 balun, but in many cases (most cases), a 1:1 balun will be better. If the impedance at the shack end of the balanced line is low, a 4:1 balun will make it even lower. You might want to consider the Elecraft BL2 which is switchable between 1:1 and 4:1 so you can choose the best ratio for each band. On 4/11/2011 7:11 PM, Wayne Conrad wrote: > My radio (K2 with the internal ATU) hasn't shipped yet, but that > shouldn't stop me from putting up an antenna, right? If only I knew > what to put up, that is. That's where I'm asking for help. > > I want to start out with an loop antenna in the attic. Why loop? Mostly > the very American idea that more wire must be better, plus it's > balanced--I hope to not need a separate RF ground, or counterpoises, or > any of that jazz). Why the attic? So I don't have to worry about > lightning protection, and because it ought to be incredibly cheap to put > up. I've spent every dime I have on the radio, you see. > > The house is the usual ~60' x ~30 feet and "L" shaped, single story, and > the major axis is North/South. The attic is full of trusses and > fiberglass, but I can get to most of it, sometimes slithering on my > belly like a snake. There are the usual electrical wires, network > cabling (OK, maybe not everyone has CAT6 in their attic), TV coax, and > AC ducts going hither and thither. My shingles are asphault. > > I have no idea what band or bands I'll be on. I don't even have my > license yet. > > My thought is that I run the loop around the perimeter of the attic, as > close to the eaves as possible. Over the radio bench, I'll punch a hole > in the ceiling and drop feedline down the wall. > > I was thinking of open-wire feeder, because I "read on the internet" > that it might be better for this application. > > It occurs to me that I could omit the 4' of feedline and just drop the > two wires down. Using the self-adhesive conduit that the hardware store > sells, I could keep those two wires at "an appropriate distance" from > each other, and white conduit looks better against a white wall than a > black cable. I don't know if that's a good idea, or what "an > appropriate distance" would be. > > I don't know if I need a balun, or even what kind. > > I don't know whether I need to keep the antenna wire off of the rafters > with insulators, or can I just let it lay there. Nor do I know if the > answer to that question changes if I eventually go QRO. > > I don't know if the length of the loop matters. > > As you can tell, the ratio of things I know to things I don't know is > pretty small. Can you please help me improve that ratio? > > Thanks, and best regards, > Wayne Conrad > __ 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] K2 + ATU + Loop antenna in the attic
Wayne, you can put up an outdoor antenna for precious little more money than that attic antenna. I'd recommend doing that if at all possible. After all, it's just wire. Even an end-fed random wire is likely to work better than anything indoors. As for the dreaded "counterpoise", try to make your antenna at > 1/4 wavelength on the lowest frequency band you'll use (longer is better) and you won't need much of a "counterpoise". Perhaps a 1/4 wavelength long wire on the lowest frequency band running along the baseboards or outside along the side of the house. BACK IN THE ATTIC I've used attic antennas in many places. In my case I was an apartment dweller for a few years so I made a point of renting the top floor apartment (usually second story) and figuring out how to get into the attic space above. (There usually is an access through a closet ceiling somewhere). I always put up a doublet - a center fed wire of whatever length I could squeeze in. I ran it along the highest place - under the ridge board just under the shingles. That put it as far as possible from wiring, ducts, etc. It can zig-zag somewhat, but I strived to keep the two halves pretty symmetrical. Frequently I ran the length of the ridge board (which in an apartment was usually about 30 feet or so between the security/firewalls that to go the roof between each apartment) then run down at the ends to the eaves - one end went one way the other end went the other for maximum separation. (That's an easy outside antenna too.) I insulated the ends where there will always be a high impedance. A bit of plastic bottle with holes punched in it works FB. But doing that helps avoid more unbalance and losses. (Insulators made from scrap bottle or clothes hangar plastic will work FB outdoors too.) For "feedline" I used two small-gauge white wires (apartment walls are invariably white). Plastic-bottle-bit spacers handle the run in the attic to a point directly over my operating desk. A fine pointed tool (e.g. ice pick) made two small holes in the ceiling right against the wall above the operating desk. The white wires come down the wall - held with a couple of staples - right to my ATU. The feeder was virtually invisible. One visitor at the desk kept asking where the feed line was. It ran up the wall 2 feet in front of his face. A balun isn't strictly necessary. Just connect one side to the rig case and the other side to the center conductor. Yes, it will be somewhat unbalanced. The only downside of that is that the feeder will radiate, but it's not a very long feeder. If you notice some "hand effects" (touching the radio changes SWR, etc.) try a balun. Elecraft has some great baluns that do well in that use. The issue with baluns is that they can become lossy at extreme impedances, and you can't really predict it too well in that environment. But many hams use them with excellent results. I had a homebrew balanced tuner on my system. ROOF You mentioned asphalt shingle roof. Excellent. I had great success radiating through those. In one apartment I couldn't get out worth a darn. One day I noticed a piece of tile from the roof. The building had concrete tiles. Put it in my microwave (with the obligatory glass of water) for a couple of minutes and that tile got smokin' hot. Concrete is a better conductor than the earth - or perhaps better said that it's a better lossy dielectric than the earth. In either case it did a bonza job absorbing my RF. QRO? I ran up to about 15 watts output in my apartment environments. Worked a lot of stations and a far share of DX - enough to keep it interesting - all CW. Even 15 watts got into our telephone but I was able to squelch it. I chose not to run more power so I'd not have to worry about neighbors sound systems, etc. Ron AC7AC -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Wayne Conrad Sent: Monday, April 11, 2011 4:12 PM To: elecraft@mailman.qth.net Subject: [Elecraft] K2 + ATU + Loop antenna in the attic My radio (K2 with the internal ATU) hasn't shipped yet, but that shouldn't stop me from putting up an antenna, right? If only I knew what to put up, that is. That's where I'm asking for help. I want to start out with an loop antenna in the attic. Why loop? Mostly the very American idea that more wire must be better, plus it's balanced--I hope to not need a separate RF ground, or counterpoises, or any of that jazz). Why the attic? So I don't have to worry about lightning protection, and because it ought to be incredibly cheap to put up. I've spent every dime I have on the radio, you see. The house is the usual ~60' x ~30 feet and "L" shaped, single story, and the major axis is North/South. The attic is full of trusses and fiberglass, but I can get to
[Elecraft] K2 + ATU + Loop antenna in the attic
My radio (K2 with the internal ATU) hasn't shipped yet, but that shouldn't stop me from putting up an antenna, right? If only I knew what to put up, that is. That's where I'm asking for help. I want to start out with an loop antenna in the attic. Why loop? Mostly the very American idea that more wire must be better, plus it's balanced--I hope to not need a separate RF ground, or counterpoises, or any of that jazz). Why the attic? So I don't have to worry about lightning protection, and because it ought to be incredibly cheap to put up. I've spent every dime I have on the radio, you see. The house is the usual ~60' x ~30 feet and "L" shaped, single story, and the major axis is North/South. The attic is full of trusses and fiberglass, but I can get to most of it, sometimes slithering on my belly like a snake. There are the usual electrical wires, network cabling (OK, maybe not everyone has CAT6 in their attic), TV coax, and AC ducts going hither and thither. My shingles are asphault. I have no idea what band or bands I'll be on. I don't even have my license yet. My thought is that I run the loop around the perimeter of the attic, as close to the eaves as possible. Over the radio bench, I'll punch a hole in the ceiling and drop feedline down the wall. I was thinking of open-wire feeder, because I "read on the internet" that it might be better for this application. It occurs to me that I could omit the 4' of feedline and just drop the two wires down. Using the self-adhesive conduit that the hardware store sells, I could keep those two wires at "an appropriate distance" from each other, and white conduit looks better against a white wall than a black cable. I don't know if that's a good idea, or what "an appropriate distance" would be. I don't know if I need a balun, or even what kind. I don't know whether I need to keep the antenna wire off of the rafters with insulators, or can I just let it lay there. Nor do I know if the answer to that question changes if I eventually go QRO. I don't know if the length of the loop matters. As you can tell, the ratio of things I know to things I don't know is pretty small. Can you please help me improve that ratio? Thanks, and best regards, Wayne Conrad __ 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] K2 ATU and 43-ft Vertical
"The base loading coil is nearly identical in design to the toroidal coil of AD5X, linked below. I do intend to find 160 & 80m tap locations for the antenna." FYI - The maximum power I've run with my 43-foot vertical and matching system is 1200 watts with no problems experienced for several months. But then one humid morning the unit did arc from the output connection across the electrical box to a nearby ground point (you could see a nice carbon trace across the box). The SWR jumped suddenly and the amplifier (ALS-1300) tripped out like it should. I replaced the output screw with a ceramic feedthru and haven't had the problem since. As Tom W8JI stated, the voltages can be extremely high especially if you are running high power. If you run an amplifier, I'd recommend using a ceramic feedthru output, and keep the output port several inches away from any ground connections. Phil - AD5X __ 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] K2 ATU and 43-ft Vertical
I happened to be down at Harbor Freight yesterday and noticed they have 20-foot telescoping aluminum flag poles on sale for $55. That should make a good vertical on 40-10 meters (almost 5/8 wave on 10) with maybe a little bit of top-loading needed on 40. It even comes with an American flag. :=) Al N1AL On Sun, 2010-06-06 at 20:06 -0400, Tom W8JI wrote: > > The base loading coil is nearly identical in design to the > > toroidal > > coil of AD5X, linked below. I do intend to find 160 & 80m > > tap > > locations for the antenna. > > I hope you have serious top loading. > > I have a video of a base loading coil throwing a two inch > long arc when running 500 watts on 160 meters into a 43-foot > vertical that is mounted over a good ground system. It > looked like the Northern Lights from Macon.:-) > > 73 Tom __ 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] K2 ATU and 43-ft Vertical
> The base loading coil is nearly identical in design to the > toroidal > coil of AD5X, linked below. I do intend to find 160 & 80m > tap > locations for the antenna. I hope you have serious top loading. I have a video of a base loading coil throwing a two inch long arc when running 500 watts on 160 meters into a 43-foot vertical that is mounted over a good ground system. It looked like the Northern Lights from Macon.:-) 73 Tom __ 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] K2 ATU and 43-ft Vertical
I am using a top-loaded 43 foot vertical (43x130-foot inverted-L) on 495.6 KHz (600 meters). The antenna Z = 0.81 - j681.5 from EzNEC. I built an air coil from #12 thhn copper wire (ordinary solid conductor electrical housewire) roughly 10-in diam by 10-inch long 39 turns and tapped it about 3/4 for a match. A tap at 2-1/2 turns matches 50-ohms coax to the xmtr which is a converted 100w NDB (aviation non-directional beacon). Details at: http://www.kl7uw.com/600m.htm The base loading coil is nearly identical in design to the toroidal coil of AD5X, linked below. I do intend to find 160 & 80m tap locations for the antenna. One thing I wanted to share was that I am using 2-foot chicken wire as ground radials lying on the ground. They are obviously short on 600m (1/4 Wave = 496 feet). Two radial are 50-foot long and one is 70-foot long. I am using the shield of my 1-5/8 inch Heliax hardline coax as the fourth radial (it is 120-foot long and has ground rod at each end). With a modified MFJ-269B, I get a measured Z = 20 + j0; the 50-ohm tap sees Z = 63 + j15 for SWR=1.3 antenna efficiency is 4% (ERP=4.15w for 100w xmtr output). With this I have been heard in BC over 1300-miles away (not in the prime DX season). 73, Ed - KL7UW -- Message: 15 Date: Sat, 5 Jun 2010 18:26:41 -0500 From: "Bob Naumann" Subject: Re: [Elecraft] K2 ATU and 43-ft Vertical To: Message-ID: <017001cb0506$8e203850$aa60a8...@com> Content-Type: text/plain; charset="us-ascii" As Don mentioned, the 2-part article in QST was written by AD5X and can also be seen here: http://www.ad5x.com/images/Articles/Match160.pdf I built one of these "matching networks" (it's not a tuner) for my 43' vertical and it works very well on 160, 80 and up. The AD5X matching network is a very clever design and makes tuning of this short radiator quite easy as it offsets the huge capacitive reactance of these antennas and even allows control of the relays right over your feedline. Very slick. I have a Zero Five vertical and it is made very well, has been up about 3 years and still looks brand new. The only difference is that with the AD5X matcher I can tune it on 160 and 80 now! The feedline makes a huge difference primarily due to the loss that will impact your performance with poor SWR. If you have a lossy feedline (like RG8X like I used at first) the antenna will appear to match pretty easily. If you switch (like I did to 1/2" hardline, with its much lower loss) you'll see the impact of all of that capacitive reactance in making tuning of the 43' antenna very difficult especially on 160 and 80. In fact, I could not match it at all on 160. 73, Bob W5OV 73, Ed - KL7UW, WD2XSH/45 == BP40IQ 500 KHz - 10-GHz www.kl7uw.com EME: 144-600w, 432-100w, 1296-60w, 3400-fall 2010 DUBUS Magazine USA Rep dubus...@hotmail.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] K2 ATU and 43-ft Vertical
> Does anyone have any experience with trying to match one > of these 43-ft > verticals, that are being offered by several > manufacturers, using the K2s > internal ATU? Is it able to find a match on 80-meter CW? > Are there any > particular brands of 43-ft verticals that you like or > don't like? Most of these > verticals that I have seen are in the mid to upper $300 > range, except for the > fiberglass one from S9 Antennas. Any opinions on that > particular antenna? Paul, I know power limits are not the problem with the K2 barefoot, but consider on 80 meters the base impedance of a fat 43 foot vertical with a modest radial system is about 12 - J 290 ohms. It would be worse with a thin wire. You would have to supply almost 1200 volts peak at almost 3 amperes to the antenna base to apply 100 watts on 80 meters. Since the 50 ohm SWR is over 100:1 on 80, it would be very difficult to get a significant percentage of your transmitter power into it on 80 (and impossible on 160) unless you put a real matching system right at the antenna. (and no, an unun is not a matching system and won't fix 80.) On 60 and 40 meters things are OK. SWR is under 6:1 so feedline efficiency would be OK without the unun. On 30 and 20 things are tough again, but far more workable than 80 and the unun at the base would help. Without the unun SWR is about 30:1. With the 4:1 unun maybe 8:1 SWR. Personally the only way I would have an antenna like that is if I remoted a good tuner right at the base. Otherwise I'd buy a trap vertical like a 6BTV or that Butternut vertical that actually has things that act like traps but that are not called traps by name. Overall, unless you put a tuner very close to the antenna, a trap vertical would work a whole lot better. For 80 you could base load the thing, and a 43 foot vertical with a good ground would be decent. Just make sure the antenna has a good base insulator, because at 100 watts you'd have over 1000 volts at the antenna base. DX Engineering has the best mechanical construction and a very good base insulator. 73 Tom __ 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] K2 ATU and 43-ft Vertical
Paul: Wire works exactly the same as aluminum so don't get carried away with the shiny look! The S9 approach makes sense. A few wires lashed to the pole or inside the pole will do. 80m is where the need for lots of radials come in since 43' is considered short for that band. Spend the $$ saved on aluminum on a remote tuner. Coax will do ok except for 80m where the Z is very low and SWR high. The K2's tuner will do fine but on 80m there's a risk of excessive current through the tuner's torroids. I've burnt them up on low Z antennas before. Above 14 mHz, a 43' vertical develops a high angle lobe, straight up, and isn't considered good for DX but will work. An inverted L, 100ft long, would be a better antenna and cheaper! Reads: http://www.eham.net/articles/21272 Got money? http://www.dxengineering.com/Parts.asp?ID=3408&PLID=286&SecID=142&DeptID=45&PartNo=DXE-MBVE-1-3ATP Rigging it up to work better: http://www.ad5x.com/images/Articles/Match160.pdf UltimateNo tuner needed. Low loss. Green. http://www.steppir.com/files/Vertical%20FACT%20Sheet.pdf Steve N4LQ - Original Message - From: "Paul Huff" To: Sent: Saturday, June 05, 2010 6:20 PM Subject: [Elecraft] K2 ATU and 43-ft Vertical > Does anyone have any experience with trying to match one of these 43-ft > verticals, that are being offered by several manufacturers, using the K2s > internal ATU? Is it able to find a match on 80-meter CW? Are there any > particular brands of 43-ft verticals that you like or don't like? Most of > these > verticals that I have seen are in the mid to upper $300 range, except for > the > fiberglass one from S9 Antennas. Any opinions on that particular antenna? > > Thanks in advance for any information offered. > > 73, > Paul - N8XMS > > __ > 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] K2 ATU and 43-ft Vertical
As Don mentioned, the 2-part article in QST was written by AD5X and can also be seen here: http://www.ad5x.com/images/Articles/Match160.pdf I built one of these "matching networks" (it's not a tuner) for my 43' vertical and it works very well on 160, 80 and up. The AD5X matching network is a very clever design and makes tuning of this short radiator quite easy as it offsets the huge capacitive reactance of these antennas and even allows control of the relays right over your feedline. Very slick. I have a Zero Five vertical and it is made very well, has been up about 3 years and still looks brand new. The only difference is that with the AD5X matcher I can tune it on 160 and 80 now! The feedline makes a huge difference primarily due to the loss that will impact your performance with poor SWR. If you have a lossy feedline (like RG8X like I used at first) the antenna will appear to match pretty easily. If you switch (like I did to 1/2" hardline, with its much lower loss) you'll see the impact of all of that capacitive reactance in making tuning of the 43' antenna very difficult especially on 160 and 80. In fact, I could not match it at all on 160. 73, Bob W5OV -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Paul Huff Sent: Saturday, June 05, 2010 5:20 PM To: elecraft@mailman.qth.net Subject: [Elecraft] K2 ATU and 43-ft Vertical Does anyone have any experience with trying to match one of these 43-ft verticals, that are being offered by several manufacturers, using the K2s internal ATU? Is it able to find a match on 80-meter CW? Are there any particular brands of 43-ft verticals that you like or don't like? Most of these verticals that I have seen are in the mid to upper $300 range, except for the fiberglass one from S9 Antennas. Any opinions on that particular antenna? Thanks in advance for any information offered. 73, Paul - N8XMS __ 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] K2 ATU and 43-ft Vertical
Paul, That is not an easy question to answer, and for your particular case, we do not have enough facts. It would be necessary to know the configuration of the radial field for that vertical, then plug that information into an antenna modeling program to find the impedance at the feedpoint to the antenna for any frequency of interest. After that, you must specify the feedline (both the type, the velocity factor and the length), as well as the details of any matching network at the base of the antenna. It is not a simple question, and the right answer is "maybe" Once all that information is available, the feedpoint impedance at the shack end of the transmission line can be calculated. With the feedpoint impedance at the shack end known, then the L network values to match it to 50 ohms resistive can be calculated. A look at the specifications for the KAT2 indicate the maximum inductance available and the maximum capacitance. If the required inductance and capacitance for the calculated L network is less than the maximum values available for the KAT2, then the answer is a definite yes. A 43 ft vertical is a bit short on 80 (but not impractical). There was a recent article in QST with a tuner at the base of a 43 ft vertical to provide a good match on 80 and 160. A 43 ft vertical is a 43 ft vertical, and the major difference between them is the effective electrical diameter of the radiator, the mechanical construction, and the price - take your pick. There is no magic in the 43 ft. length except it is practical to erect without a large crew tugging on guy lines, many can simply be "walked up". 73, Don W3FPR Paul Huff wrote: > Does anyone have any experience with trying to match one of these 43-ft > verticals, that are being offered by several manufacturers, using the K2s > internal ATU? Is it able to find a match on 80-meter CW? Are there any > particular brands of 43-ft verticals that you like or don't like? Most of > these > verticals that I have seen are in the mid to upper $300 range, except for the > fiberglass one from S9 Antennas. Any opinions on that particular antenna? > > Thanks in advance for any information offered. > > __ 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] K2 ATU and 43-ft Vertical
Paul, the K2 internal tuner is a wide-range device and should be able to match the 43 ft vertical from 10 thru 80 unless you happen to pick an unfortunate length of feedline. The impedance seen by the tuner will depend on the feedline length. All of the available 43 ft verticals should work equally well electrically. Their mechanical construction and subsequent ruggedness will vary as will their ease of assembly and erection. I just use a 43 ft piece of AWG 12 wire suspended from a lightweight fiberglas Spiderbeam pole, and it works fine. Total cost should be less than $150, mostly for the pole. It cannot be emphasized highly enough that the performance of any of these antennas will depend almost entirely on the radial system used. Try for at least 32 radials, each as long as your space permits up to 65 ft or so. Other than the radials, the next best thing you can do to improve performance is to use a remote tuner at the base. This will eliminate most of the feedline losses you will incur when using the K2 internal tuner. I use a CG-3000, and it is "okay". I would dearly love for Elecraft to offer a remote tuner, however!!Are you listening, Aptos ;>) ? 73 Craig AC0DS __ 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] K2 ATU and 43-ft Vertical
Does anyone have any experience with trying to match one of these 43-ft verticals, that are being offered by several manufacturers, using the K2s internal ATU? Is it able to find a match on 80-meter CW? Are there any particular brands of 43-ft verticals that you like or don't like? Most of these verticals that I have seen are in the mid to upper $300 range, except for the fiberglass one from S9 Antennas. Any opinions on that particular antenna? Thanks in advance for any information offered. 73, Paul - N8XMS __ 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] K2 ATU Finally Finished, THX ALL
To Don and everyone else who encouraged and helped me build my K2 I would like to say thank you, after sitting in a box for about 8 months due to a move at home, then a move at work, I officially moved into my new lab today and got my mitts on a power meter, and finished the ATU cal, now that I also have an antenna erected in my apartment, I hope to meet some of you on the air in the near future. Thanks again to everyone, I cant wait until I save enough money for my next one (another K2 or possible K1). Matt Palmer KD8DAO ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] [K2] ATU
Thanks to everyone who responded to my question about choosing an ATU. I'll be using it solely for my K2 so with your advise I've decided to go with the KAT2. Thanks again! 73, Kristina KE7LUC ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] [K2] ATU
Hello Kristina The KAT2 has one big advantage over the T1. (I have both of them). With the T1, you are looking at just one antenna. With the KAT2, you have two separate ANT ports, and can switch between them with a button press. On a band-by-band basis, the KAT2 remembers its setting for whatever antenna is connected to either port, so you don't have to retune when switching bands or antennas. Also, ;using a barefoot K2, you have a POWER measuring circuit that is just an rf voltmeter across the 50 ohm output, and it is only accurate when the load is a true 50 ohms, such as with a good dummy load. The KAT2 has a true wattmeter circuit, and measures the power, whether you have a tight match or not. Another advantage of the KAT2 is that it is internal, so when you go to the field, like for FD, that is one less piece of gear to drag along. Personally, I thought the KAT2 was the slickest piece of engineering in the whole K2 options line. Good luck and 73 Bob N6WG - Original Message - From: "Kristina Wright" <[EMAIL PROTECTED]> To: "Elecraft Reflector" Sent: Tuesday, November 13, 2007 11:06 AM Subject: [Elecraft] [K2] ATU > Hello group, > I'm needing a tuner for use with my K2, and wanted to know the pros > and cons of the KAT2 vs. the T1. Is the only difference that the T1 is > stand-alone and the KAT2 is internal? Thanks in advance for your advice. > > 73, > Kristina KE7LUC > ___ > Elecraft mailing list > Post to: Elecraft@mailman.qth.net > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] [K2] ATU
Kristina, The KAT2 has a much greater tuning range, handles 2 antennas and remembers the last tuned settings for each band on both antennas. Communication between the K2 and KAT2 is automatic and quite painless. Of course, if you need a remote tuner (mounted at the antenna for example), the T1 is the better choice - the KAT2 must live at the location of the K2. 73, Don W3FPR Kristina Wright wrote: Hello group, I'm needing a tuner for use with my K2, and wanted to know the pros and cons of the KAT2 vs. the T1. Is the only difference that the T1 is stand-alone and the KAT2 is internal? Thanks in advance for your advice. ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] [K2] ATU
Hello group, I'm needing a tuner for use with my K2, and wanted to know the pros and cons of the KAT2 vs. the T1. Is the only difference that the T1 is stand-alone and the KAT2 is internal? Thanks in advance for your advice. 73, Kristina KE7LUC ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] K2 ATU
Tim, Even when the KAT2 is attached, you can still hear signals through the base K2 antenna jack - that is NOT a problem. If you cannot receive through the ANT1 or ANT2 jacks on the KAT2, the problem must be with the KAT2. Since I presume it worked before, look for the easy things first, like a break in the input coax or improper seating of the crimp pins in the connector. If you set the menu to ATU CALP, you should be able to make a continuity check from the input coax center conductor to the center conductor of ANT1 or ANT2. 73, Don W3FPR Ellam, Timothy St. J. wrote: I have a problem which I am sure is my own error, but for the life of me I cannot seem to find the fix. I just switched the K2/100 module with regular K2 cover which has the K2ATU. The menu shows ATU as "auto", but neither Ant jacks 1 or 2 seem to function, The regular BNC that is not connected to the ATU works fine. I thought once the ATU was installed that jack was disabled? Am I missing a menu change or do I have a more substantive problem? ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
RE: [Elecraft] K2 ATU
There is a RF cable from the ATU to the mainboard. The auxbux is detecting the ATU so that's connected, but the RF most likely is not. The RF cable plugs into the main board at RF-P6. Do not connect it to RF-P3, the battery connector! Dan / WG4S / K2 #2456 neither Ant jacks 1 or 2 seem to function, The regular BNC that is not connected to the ATU works fine. ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] K2 ATU
I have a problem which I am sure is my own error, but for the life of me I cannot seem to find the fix. I just switched the K2/100 module with regular K2 cover which has the K2ATU. The menu shows ATU as "auto", but neither Ant jacks 1 or 2 seem to function, The regular BNC that is not connected to the ATU works fine. I thought once the ATU was installed that jack was disabled? Am I missing a menu change or do I have a more substantive problem? 73 Tim VE6SH [EMAIL PROTECTED] === This e-mail is intended only for the named recipient(s) and may contain information that is privileged, confidential and/or exempt from disclosure under applicable law. No waiver of privilege, confidence or otherwise is intended by virtue of communication via the internet. Any unauthorized use, dissemination or copying is strictly prohibited. If you have received this e-mail in error, or are not named as a recipient, please immediately notify the sender and destroy all copies of this e-mail. Please be aware that internet communications are subject to the risk of data corruption and other transmission errors. For information of extraordinary sensitivity, we recommend that our clients use encryption software when they communicate with us by e-mail. By submitting your or another individual's personal information to McCarthy Tétrault LLP or its affiliates, service providers and agents, you agree, and confirm your authority from such other individual, to our collection, use and disclosure of such personal information in accordance with our privacy policy available at www.mccarthy.ca . McCarthy Tétrault contact information may be found at www.mccarthy.ca/en/contactus . ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
RE: [Elecraft] K2 ATU Pout Question
Jerry, See page 18 of the KAT2 manual (and the chart on page 21) for the full details, but the 'CALS' setting will bypass the matching network and I believe that is what you want to accomplish. 73, Don W3FPR > -Original Message- > > I am disappointed that I received no reply to my query re the KAT2. > Perhaps I did not ask the question clearly. > > I would like to read the UNMATCHED Forward and Reflected power on > the antenna. This information would help me trim the antenna to > resonance. I think that I can see the UNMATCHED reading by > putting the ATU in the POUT mode. Is that correct? > > I don't find this question addressed in the KAT2 construction > manual but feel that at one time I have read it somewhere. > > Jerry/k6iii > San Jose, CA > > > > > Is it correct that with the KAT2 set to read Pout, that I am > reading the true > forward and reflected values from the match and not the ATU > Corrected match? > > I want to be able to read the Unmatched SWR. > > Jerry/k6iii > San Jose, CA > K2 s/n 500 > ___ ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] K2 ATU Pout Question
I am disappointed that I received no reply to my query re the KAT2. Perhaps I did not ask the question clearly. I would like to read the UNMATCHED Forward and Reflected power on the antenna. This information would help me trim the antenna to resonance. I think that I can see the UNMATCHED reading by putting the ATU in the POUT mode. Is that correct? I don't find this question addressed in the KAT2 construction manual but feel that at one time I have read it somewhere. Jerry/k6iii San Jose, CA Is it correct that with the KAT2 set to read Pout, that I am reading the true forward and reflected values from the match and not the ATU Corrected match? I want to be able to read the Unmatched SWR. Jerry/k6iii San Jose, CA K2 s/n 500 ___ ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] K2 ATU Pout Question
Is it correct that with the KAT2 set to read Pout, that I am reading the true forward and reflected values from the match and not the ATU Corrected match? I want to be able to read the Unmatched SWR. Jerry/k6iii San Jose, CA K2 s/n 500 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] K2 ATU question
In message <[EMAIL PROTECTED]>, Ullrich von Bassewitz <[EMAIL PROTECTED]> writes Surely this doesn't matter. Once the ATU in the K2 has been tuned once, then it won't attempt to correct for any mismatch (caused by tuning the mag loop) until you press the tune button again. Trev G3ZYY Unfortunately, it's not that easy. Matching a combined feeder/antenna system with a tuner so that the PA sees 50 ohms doesn't mean that the antenna is actually working. What you say is true, provided that the antenna is resonant, and has 50 ohms with no imaginary part. But if you don't know that for sure, for example if you're experimenting, or because the antenna has a very low bandwidth (see below), just matching it with the ATU won't help. A mag loop is special, because it has a very narrow bandwidth (often 10khz or less), so changing frequency means retuning the antenna. But to tune the antenna, one needs to know the real SWR. And this is the point where the ATU needs to be switched off, because it will just correct the SWR as far as the PA is concerned, but it will not make the antenna resonant. Regards Uz -- Trevor Day SIP: [EMAIL PROTECTED] ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] K2 ATU question
On Tue, Sep 14, 2004 at 07:24:58PM +0300, Ben Dalfen wrote: > No problem. Just use PF1 or PF2 for switching your ATU between active and > CALS modes. Takes 2 seconds. Is it possible to program PF1 or PF2 to switch the ATU between modes? All I have managed was to program these keys to select the ATU submenu. So after a band change, I still have to - hold down PF2 to select the ATU menu entry - tap Band +/- or turn the VFO knob to switch the mode - tap any other key to leave the menu which is still pretty inconvenient. Regards Uz -- Ullrich von Bassewitz [EMAIL PROTECTED] ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] K2 ATU question
On Tue, Sep 14, 2004 at 11:23:18AM -0300, Michael Harris wrote: > Can't see the problem. I have a log periodic for 18-30MHz on ant-1 and a > vertical for lower bands on ant-2. It does not matter if the atu stays in > circuit and "tunes" the matched resonant antenna. Just the same as > matching to the dummy load. My vertical is a good 50 ohm match on 10MHz > but I also very occasionally press it into service on 7MHz where the ATU > keeps the PA happy. Unfortunately, it's not that easy. Matching a combined feeder/antenna system with a tuner so that the PA sees 50 ohms doesn't mean that the antenna is actually working. What you say is true, provided that the antenna is resonant, and has 50 ohms with no imaginary part. But if you don't know that for sure, for example if you're experimenting, or because the antenna has a very low bandwidth (see below), just matching it with the ATU won't help. A mag loop is special, because it has a very narrow bandwidth (often 10khz or less), so changing frequency means retuning the antenna. But to tune the antenna, one needs to know the real SWR. And this is the point where the ATU needs to be switched off, because it will just correct the SWR as far as the PA is concerned, but it will not make the antenna resonant. Regards Uz -- Ullrich von Bassewitz [EMAIL PROTECTED] ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] K2 ATU question
No problem. Just use PF1 or PF2 for switching your ATU between active and CALS modes. Takes 2 seconds. Ben Dalfen 4X1BD ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
RE: [Elecraft] K2 ATU question
Hi Mike, > Can't see the problem. I have a log periodic for 18-30MHz on ant-1 and a > vertical for lower bands on ant-2. It does not matter if the atu stays in > circuit and "tunes" the matched resonant antenna. Just the same as > matching to the dummy load. My vertical is a good 50 ohm match on 10MHz > but I also very occasionally press it into service on 7MHz where the ATU > keeps the PA happy. What you described is correct. However, a magnetic loop or other narrow-band antenna that needs to be tuned to frequency should be run without an auto-tuner in the transmitter. When an auto-tuner is engaged it is nearly impossible to tune the loop correctly to resonance resulting in troublesome matches that can stress both the loop antenna and tuner components. I use magnetic loops with other transceivers that allow the tuner to be disabled, but not with a K2. My K2 is used with numerous wire dipoles, full-sized loops, an LPDA, and verticals, but not with magnetic loops. Gus Hansen Email: [EMAIL PROTECTED] . If you think no one cares that you are alive try missing a couple of loan payments. ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] K2 ATU question
G'day, > I'm using an indoor wire antenna for all bands except 30m, where I'm testing a > home built mag loop. The wire antenna is connected to ant #1, the mag loop to > ant #2. The mag loop is resonant and doesn't use the ATU, while the wire > antenna needs the ATU. > Now each time, I change to 30m, I do have to disable the ATU manually by > switching it into CALS mode, which is very inconvenient. Alternatively, I can > connect a dummy load, tune the ATU into the dummy load on 30m, and then > reconnect the mag loop. The problem with this second approach is that after > accidently tapping tune, I will have to repeat the whole process (disconnect > antenna, connect the dummy load, ...). > > Since the given setup (having a resonant antenna and another one that needs > the ATU) seems pretty common to me, I do assume that there is a simpler > solution. Is it possible to disable the ATU for one of both antenna > connectors, or for a specific band? Any other trick to make changing bands > simpler? Can't see the problem. I have a log periodic for 18-30MHz on ant-1 and a vertical for lower bands on ant-2. It does not matter if the atu stays in circuit and "tunes" the matched resonant antenna. Just the same as matching to the dummy load. My vertical is a good 50 ohm match on 10MHz but I also very occasionally press it into service on 7MHz where the ATU keeps the PA happy. Regards, Mike VP8NO ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] K2 ATU question
I've recently build my K2 (serial 4377) which works great, and I'm very happy with it. Unfortunately, I can only use indoor or very small outdoor antennas, so I'm currently experimenting with mag loops. While doing so, I noticed that ATU use becomes very inconvenient. This is my scenario: I'm using an indoor wire antenna for all bands except 30m, where I'm testing a home built mag loop. The wire antenna is connected to ant #1, the mag loop to ant #2. The mag loop is resonant and doesn't use the ATU, while the wire antenna needs the ATU. Now each time, I change to 30m, I do have to disable the ATU manually by switching it into CALS mode, which is very inconvenient. Alternatively, I can connect a dummy load, tune the ATU into the dummy load on 30m, and then reconnect the mag loop. The problem with this second approach is that after accidently tapping tune, I will have to repeat the whole process (disconnect antenna, connect the dummy load, ...). Since the given setup (having a resonant antenna and another one that needs the ATU) seems pretty common to me, I do assume that there is a simpler solution. Is it possible to disable the ATU for one of both antenna connectors, or for a specific band? Any other trick to make changing bands simpler? Regards Uz -- Ullrich von Bassewitz [EMAIL PROTECTED] ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
