James, I, too, have noticed what I believe you are noticing. It seems to me that the jumps in the tracking of VFO A and VFO B occur at the transitions of the bandpass filters. It is as if when the bandpass relays switch, the VFOs lose their synchronization. (Of course, I could be wrong, but it seems that way to me) I tried to discover the repeatable conditions for its occurrence, but other than quickly tuning the main VFO knob over large excursions of frequency with linked VFOs, I could not discover any real reason for the occurrence.
Concerning the motorboat zipper noise, I have 8 pole filters in both the main and sub receivers, but they are evidently not exactly matched. When I tune quickly, the phase difference between the two receivers, due to the tuning delays in the VCOs kicks in and causes the motorboating. As soon as I stop tuning, the phase differences come back into sync (or nearly so) and I do not have the motorboating. Now if there is a tutorial which describes how to find the actual offset of the 8 pole filters out there, we could find the offsets and adjust them accordingly, and be rid of that problem. That is my diagnosis, and I'm sticking to it (at least until the true reasons are discovered.) Bill W4ISH -- With my call, you only have to know half the Morse Code -- Just the Dits. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
