Clarification - when I said the K1 ATU wouldn't make a difference, I mean "just as an installed option" and wasn't considering it actually inline at the time
--Andrew On Thu, Aug 30, 2012 at 9:37 AM, Geoffrey Mackenzie-Kennedy <lx...@pt.lu>wrote: > Hello Gil, > > The ATU in your K1 could be making the difference. It will or should > transform the impedance presented by the 33.5 ft wire and 13 ft > counterpoise > to 50 ohms resistive, which is the source impedance which the K1's receiver > likes to see. The K2's receiver would also like to see a 50 ohm resistive > source, but without an ATU it will see whatever source impedance is > presented by the wire and counterpoise. > > On 20m the wire and counterpoise would be seen by the K2's receiver as a > fairly high impedance source, 2000 ohms or more resistive with some > inductance in series. On 40m, and depending on how you have the wire and > counterpoise deployed and the effects of nearby objects, the receiver could > be seeing a source whose resistive part is 20 ohms or less with some > capacitance in series. These are rough values simply to illustrate one > possible reason why your K2 is deaf on 20m, and not quite as deaf on 40m. > > > If possible bypass the ATU in the KX1, and then make a comparison between > your K1 and K2. If your K1 becomes deaf as well, then buy an Elecraft ATU > for your K2. If buying an ATU is not an option, it is not difficult to > homebrew a L Network for use as an ATU. If you do decide to homebrew a L > network, I suggest that the coil be solenoid wound rather than wound on a > toroidal core. > > 73, > > Geoff > LX2AO > > > On August 30, 2012 at 8:03 AM, "Gil G." <g...@keskydee.com> wrote: > > > > > Hello, > > > I knew this title would grab some attention ;-) > > > Well, since my K1 worked so well, I decided to build a K2. > > It took me 30 hours over three days. Everything works, but… > > > First, the receiver is pretty deaf on 20m. Not much static at all, faint > > signals. > > I plugged in my K1 on the same wire, and what I could barely hear on 20m > > on the K2 came in full blast on the K1. > > The preamp helps a little, but not much. > > On 40m, the score is closer, but still advantage to the K1 over the K2 > > with preamp on. > > I can use FL1 and FL2, but with 3, the signal is very attenuated, with 4 > > (200Hz), usually gone. > > The other bands, I haven't listened enough yet to make a diagnosis… I can > > hear more static than on 20m. > > I have set the filters as indicated in the manual. > > > The K1 has the ATU, would that make such a difference? > > I use a 35.5ft wire with 13ft counterpoise, directly out the BNC via a > > binding post. > > > By the way, I do get full output power on the K2 on all bands. > > I precisely peaked all bands on receive, then on transmit with my QRP > > wattmeter. > > > Any advise? > > > Thanks! > > > Gil. > > ______________________________________________________________ > 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
