Re: [Elecraft] KAT2 with EFHW antenna
An EFHW is a very efficient antenna, but the usual tuner needs help. One way to use the EFHW is to put a toroidal winding at the base of the antenna, between the tuner and the antenna. Bifilar or trifilar or quadrifilar windings configured as a tapped winding will reduce the tough impedance to something that the tuner will handle easily. The 80 meter version of this, an end-fed half-wave L fed against ground is probably the best single wire antenna for 80 meters that there is. 73, Guy. On Tue, Aug 23, 2011 at 11:50 PM, Phillip Shepard wrote: > Thanks for all of the great advice. This reflector is a fountain of > knowledge! I checked the 33' antenna/16' counterpoise combination with an > MFJ259B, and it indicated over 25:1 SWR. Extending the antenna to 39' and > adding a second "radial" of 6' gave an SWR reading of about 11:1 with the > antenna analyzer. The KAT2 seems to handle that much better. This will > get > me through one or two SOTA peaks at Crater Lake later this week; and I can > look for better solutions after that. Thanks again. > > 73, > > Phil, NS7P > > -Original Message- > From: elecraft-boun...@mailman.qth.net > [mailto:elecraft-boun...@mailman.qth.net]On Behalf Of Phillip Shepard > Sent: Tuesday, August 23, 2011 4:00 PM > To: elecraft@mailman.qth.net > Subject: [Elecraft] KAT2 with EFHW antenna > > > I have been using my K2 with an MFJ tuner to feed an end fed halfwave wire > for portable use (like SOTA). The 20m antenna is 33' long and I use one or > two 16' counterpoise wires. It seems to work well for what it is and 10W. > I just built and installed the KAT2 ATU into the K2 to lighten my pack by > the loss of the MFJ. The KAT2 tuner checked out fine on the bench, but it > had a very hard time getting a good match to the antenna. In AUTO mode, it > only got the SWR down to about 5:1. I put it in ALT mode, and it spent a > long time searching before it got down to between 3:1 and 4:1, depending on > the 20m frequency. I added about 2" of wire to the antenna, and the tuer > got down to about 2:1 to 2.5:1. I added another foot of wire (now 36'), > and > it got down to about 1.5:1. Five or six feet added yielded a perfect match > (1:1). So I now have a 39' wire for 20m use. > > Is this normal? Should the KAT2 be able to more easily match the 33' > halfwave antenna? Thank you. > > 73, > Phl, NS7P > > __ > 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] KAT2 with EFHW antenna
Thanks for all of the great advice. This reflector is a fountain of knowledge! I checked the 33' antenna/16' counterpoise combination with an MFJ259B, and it indicated over 25:1 SWR. Extending the antenna to 39' and adding a second "radial" of 6' gave an SWR reading of about 11:1 with the antenna analyzer. The KAT2 seems to handle that much better. This will get me through one or two SOTA peaks at Crater Lake later this week; and I can look for better solutions after that. Thanks again. 73, Phil, NS7P -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net]On Behalf Of Phillip Shepard Sent: Tuesday, August 23, 2011 4:00 PM To: elecraft@mailman.qth.net Subject: [Elecraft] KAT2 with EFHW antenna I have been using my K2 with an MFJ tuner to feed an end fed halfwave wire for portable use (like SOTA). The 20m antenna is 33' long and I use one or two 16' counterpoise wires. It seems to work well for what it is and 10W. I just built and installed the KAT2 ATU into the K2 to lighten my pack by the loss of the MFJ. The KAT2 tuner checked out fine on the bench, but it had a very hard time getting a good match to the antenna. In AUTO mode, it only got the SWR down to about 5:1. I put it in ALT mode, and it spent a long time searching before it got down to between 3:1 and 4:1, depending on the 20m frequency. I added about 2" of wire to the antenna, and the tuer got down to about 2:1 to 2.5:1. I added another foot of wire (now 36'), and it got down to about 1.5:1. Five or six feet added yielded a perfect match (1:1). So I now have a 39' wire for 20m use. Is this normal? Should the KAT2 be able to more easily match the 33' halfwave antenna? Thank you. 73, Phl, NS7P __ 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] K3's 2-meter reference-lock module can now track an external reference
Hi all, If you're using the "RFLK" (ref lock) option with your K3's 2-meter module (K144XV), *and* an external 10-MHz reference, you may want to try the latest K3 field-test firmware. The offsets for the RFLK option, in CONFIG:XVn OFS, can now be set automatically, based on the CONFIG:REF CAL parameter. Since REF CAL itself can track an external reference (via the K3EXREF option), you can now get the full benefit of the external reference from 160 through 2 meters. If you'd like to try the field-test firmware, please contact me directly. 73, Wayne N6KR __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Installing K2 Internal Mic Adaptor
Roy, I would suggest removing the capacitor and adding the 82 mHy shielded choke that is included with the A to B mod kit. Yes, you will also have to add a 47k resistor in series with C24 (see the K2 A to B instructions). That will make the sidetone smoothing equal to the post 3000 SN K2s. The 82 mHy inductor will be positioned high enough on the Control Board that it is out of the way for the installation of the IMA. 73, Don W3FPR On 8/23/2011 11:14 AM, Roy Morris wrote: > My K2 is an early serial number (2###). I am getting ready to install a K2 > Internal Mic Adaptor that fits between the control board and the front panel > board. There is a rather large component I mounted years ago on RP5 to > smooth the sidetone. This component (I believe it is a 47uF cap but not > sure) needs to be removed or relocated in order to install the mic adaptor. > Any suggestions would be appreciated. Thanks Roy Morris W4WFB > > __ > 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] KAT2 with EFHW antenna
Phil, As others have responded, attempting to tune the end of a half-wave wire is beyond the range of most tuners, including the KAT2. Your added wire provided a compromise length, because the feedpoint impedance was reduced. Because the impedance of the EFHW is high, my favorite tuning section for a half wave antenna is a parallel tuned tank circuit - the radiator connects to one side of the parallel circuit and your counterpoise (or ground) connects to the "cold end". Tune the paralled tank circuit for resonance near the operating frequency (and make it a permanent part of the antenna). Then wrap a few turns around the ground end of the inductor and use that "link" to connect to the KAT2. The fixed tuned circuit will handle the high impedance, and the impedance of the "link" will be much lower (depends on the square of the turns ratio). The KAT2 will do the job of matching into that link as you move about the band. In other words, you make a fixed "tuner" that becomes part of your EFHW dipole (no variable capacitor to tune the antenna - use a fixed capacitor that resonates with the inductor approximately mid-band. The KAT2 will tune quite nicely into the link winding and produce a low SWR. The alternative is to use a non-resonant wire length that provides a sufficiently low impedance as to be within the matching range of the tuner. The W3EDP antenna is one of those examples. Use that approach if you want to use the same antenna wire for multiple bands. As I recall, the W3EDP radiator is 85 feet long and the "counterpoise" is 17 feet for use on 80 meters and up. Half those lengths would work on 40 and up. I look at the W3EDP as "sort-of" an off-center-fed" dipole - the counterpoise does not have to be on the ground to work well. 73, Don W3FPR On 8/23/2011 7:00 PM, Phillip Shepard wrote: > I have been using my K2 with an MFJ tuner to feed an end fed halfwave wire > for portable use (like SOTA). The 20m antenna is 33' long and I use one or > two 16' counterpoise wires. It seems to work well for what it is and 10W. > I just built and installed the KAT2 ATU into the K2 to lighten my pack by > the loss of the MFJ. The KAT2 tuner checked out fine on the bench, but it > had a very hard time getting a good match to the antenna. In AUTO mode, it > only got the SWR down to about 5:1. I put it in ALT mode, and it spent a > long time searching before it got down to between 3:1 and 4:1, depending on > the 20m frequency. I added about 2" of wire to the antenna, and the tuer > got down to about 2:1 to 2.5:1. I added another foot of wire (now 36'), and > it got down to about 1.5:1. Five or six feet added yielded a perfect match > (1:1). So I now have a 39' wire for 20m use. > > Is this normal? Should the KAT2 be able to more easily match the 33' > halfwave antenna? Thank you. > > 73, > Phl, NS7P > > __ > 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] KAT2 with EFHW antenna
But, on the positive side, that very high impedance means an unusually efficient antenna since there is almost no ground current flowing at all. I use a setup like that at my home station - 1/2 wavelength long wire on 80 meters - with a homebrew manual L-network. Does a great job. One reason why small auto-tuners cannot handle that huge impedance is because of the voltages involved. Thousands of volts commonly exist even with fairly low power. The capacitors and inductors in most automatic tuners simply aren't rated for that. Ron AC7AC -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of David Gilbert Sent: Tuesday, August 23, 2011 4:20 PM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] KAT2 with EFHW antenna The simple answer to your question is "no". An end fed halfwave would theoretically present a few thousand ohms to your feedline, giving you an SWR of several tens to one. Consider this it is likely that the tuner with the greater loss will more easily give you a "match" to a difficult load. 73, Dave AB7E __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KAT2 with EFHW antenna
The simple answer to your question is "no". An end fed halfwave would theoretically present a few thousand ohms to your feedline, giving you an SWR of several tens to one. Consider this it is likely that the tuner with the greater loss will more easily give you a "match" to a difficult load. 73, Dave AB7E On 8/23/2011 4:00 PM, Phillip Shepard wrote: > I have been using my K2 with an MFJ tuner to feed an end fed halfwave wire > for portable use (like SOTA). The 20m antenna is 33' long and I use one or > two 16' counterpoise wires. It seems to work well for what it is and 10W. > I just built and installed the KAT2 ATU into the K2 to lighten my pack by > the loss of the MFJ. The KAT2 tuner checked out fine on the bench, but it > had a very hard time getting a good match to the antenna. In AUTO mode, it > only got the SWR down to about 5:1. I put it in ALT mode, and it spent a > long time searching before it got down to between 3:1 and 4:1, depending on > the 20m frequency. I added about 2" of wire to the antenna, and the tuer > got down to about 2:1 to 2.5:1. I added another foot of wire (now 36'), and > it got down to about 1.5:1. Five or six feet added yielded a perfect match > (1:1). So I now have a 39' wire for 20m use. > > Is this normal? Should the KAT2 be able to more easily match the 33' > halfwave antenna? Thank you. > > 73, > Phl, NS7P > __ 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] KAT2 with EFHW antenna
Phillip Shepard wrote: > I put it in ALT mode, and it spent a > long time searching before it got down to between 3:1 and 4:1, depending > on > the 20m frequency. I added about 2" of wire to the antenna, and the tuer > got down to about 2:1 to 2.5:1. I added another foot of wire (now 36'), > and > it got down to about 1.5:1. Five or six feet added yielded a perfect > match > (1:1). So I now have a 39' wire for 20m use. > > Is this normal? Should the KAT2 be able to more easily match the 33' > halfwave antenna? Thank you. > Probably normal. End-fed half-wave antennas are 4-5000 ohms impedance, so you're asking the tuner to match an 80-100:1 SWR which is beyond the range of most tuners. 73, Bill -- View this message in context: http://elecraft.365791.n2.nabble.com/K3-S-meter-oddities-tp6676870p6718255.html Sent from the Elecraft 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] KAT2 with EFHW antenna
I have been using my K2 with an MFJ tuner to feed an end fed halfwave wire for portable use (like SOTA). The 20m antenna is 33' long and I use one or two 16' counterpoise wires. It seems to work well for what it is and 10W. I just built and installed the KAT2 ATU into the K2 to lighten my pack by the loss of the MFJ. The KAT2 tuner checked out fine on the bench, but it had a very hard time getting a good match to the antenna. In AUTO mode, it only got the SWR down to about 5:1. I put it in ALT mode, and it spent a long time searching before it got down to between 3:1 and 4:1, depending on the 20m frequency. I added about 2" of wire to the antenna, and the tuer got down to about 2:1 to 2.5:1. I added another foot of wire (now 36'), and it got down to about 1.5:1. Five or six feet added yielded a perfect match (1:1). So I now have a 39' wire for 20m use. Is this normal? Should the KAT2 be able to more easily match the 33' halfwave antenna? Thank you. 73, Phl, NS7P __ 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: Poor sound on FM
Anything of this would be nice, 100-3200Hz is my prefered "armchair bandwidth" for FM. 73 Michael -- View this message in context: http://elecraft.365791.n2.nabble.com/K3-Poor-sound-on-FM-tp6713097p6717762.html Sent from the Elecraft 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] Installing K2 Internal Mic Adaptor
My K2 is an early serial number (2###). I am getting ready to install a K2 Internal Mic Adaptor that fits between the control board and the front panel board. There is a rather large component I mounted years ago on RP5 to smooth the sidetone. This component (I believe it is a 47uF cap but not sure) needs to be removed or relocated in order to install the mic adaptor. Any suggestions would be appreciated. Thanks Roy Morris W4WFB __ 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] KX3 AF/RF gain control
"Tap" and "Hold". After 11 years with Elecraft radios, I might have figured that one out! 73, Rick K7MW On Aug 23, 2011, at 7:18 AM, Lyle Johnson wrote: > Rick, > > You tap to toggle the control between RF Gain and AF Gain. > > 73, > > Lyle KK7P > >> In the photo of the KX3, the gain control is labeled AF/RF. Since >> this is not a concentric control, it must adjust the gain at both >> stages with one knob... __ 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] KX3 AF/RF gain control
Rick, You tap to toggle the control between RF Gain and AF Gain. 73, Lyle KK7P > In the photo of the KX3, the gain control is labeled AF/RF. Since > this is not a concentric control, it must adjust the gain at both > stages with one knob... __ 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] KX3 AF/RF gain control
In the photo of the KX3, the gain control is labeled AF/RF. Since this is not a concentric control, it must adjust the gain at both stages with one knob. I am wondering if we will be able to change the balance of the effect that this control has on the two stages. With superhet designs, my thinking has always been to set the AF control to match the requirements of the speaker or headphones and use the RF control to adjust for changes in signal strength, but I have no experience with DC radios. The KX3 seems to be a very big step up in the design of DC radios, so I would like to see what others think on this subject. 73, Rick Dettinger K7MW __ 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] The "Best" Settings
Al Lorona wrote: > > I believe it comes down to this: use whichever settings your ears tell you > sound > best. This is going to require that you spend time tweaking controls to > see how > you perceive their effect. > I agree with Al but you need to turn down the RF Gain or your K3 will sound noisy no matter what you tweak. 73, Barry N1EU -- View this message in context: http://elecraft.365791.n2.nabble.com/K3-The-Best-Settings-tp6714606p6715702.html Sent from the Elecraft 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