Hello everybody, Tonight I wanted to work station on 3504kHz but was not able to tune with K3 to transmit on that frequency. Here are the facts:
- The antenna is multi-band dipole, a.k.a Van Gorden or Doublet - 137ft dipole center fed with 450 Ohm ladder line. - I do not use KAT3, it is installed but bypassed in this configuration. I use MFJ-986 Differential-T tuner with built-in balun. - I able to tune down to 1.1:1 on all frequencies above about 3505 with K3 and any other transceiver I tried. The optimal tuner settings at any given frequency are the same for all transceivers (besides K3 I tried Kenwood TS-930S and TS-570D with autotuner bypassed on both). - My setting for tune power on K3 is 30W, on TS-570D - 30W, on TS-930S - 50W - On frequencies 3501 to 3505 with both Kenwood transceivers the tuning is normal. With K3 the SWR is through the roof and there is no way I can find resonance to see reasonable SWR. - There is significant "hysteresis" to the phenomenon. When I move down on frequency I am able to tune down to 3505 or so. When I see the problem I have to return to about 3520 to see normal SWR again. - The problem seem to be apparent only on this small part of the band. I took time to go down from 3900 and was able to tune everywhere. Also I didn't see any problem on low portion of 40m band. Unfortunately, I don't have other antenna on 80m to compare. However, the fact that I don't see any issues with the same setup with different transceivers tells me that antenna and tuner probably are OK. I tried to tune K3 with different power: from 10W to 50W - same behavior. I do not have dummy load available at this moment, I will try tomorrow with dummy load. Any thoughts? 73, Igor, N1YX ______________________________________________________________ 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
