Don, Setting each VFO to a frequency within the 15M band cured the "VFO B-A" pop. I checked the other bands, and found 20M "popping" when changing VFOs. One was set to 14.223, the other to 14.342. I found a pop as I tuned through ~14.348, so setting that VFO to a frequency lower that that, cured it. Does the rig effectively tune through the frequencies between the VFOs as it is switched, so if there are pops, it might see them?
I still hear pops that are louder than I like as I tune from 15M to 12M, and 17M. When going from each of those bands into 15, it is more of a click - like between 20M and 10M. I guess I can live with that. Thanks again for your patience. and for sharing your experience. 73, Jim KO5V -----Original Message----- >From: Don Wilhelm <donw...@embarqmail.com> >Sent: Jul 3, 2019 4:49 PM >To: Jim KO5V <k...@earthlink.net>, Elecraft List <elecraft@mailman.qth.net> >Subject: Re: Fw: Re: K2: "Pop" when switching certain bands > >Jim, > >There is no relay action when changing from VFO A to B or the other way >around - the MCU just sends different data to the PLL and PLL Reference >Oscillator. > >However, 20 MHz may be on the lower limit of the available VFO tuning >range for 15 meters. >Try tuning the VFO for both A and B back into the 15 meter band limits. > >73, >Don W3FPR > > > >On 7/3/2019 3:57 PM, Jim KO5V wrote: >> Hi again, >> >> I did as Don suggested, and checked the values of all of the capacitors >> around U1, and all of the band-switching relays. I also re-flowed all of >> their solder joints. With the bottom panels, top panel and the left-side >> panel off, the click in the audio was a lot better, and switching VFOs on >> 15M was quiet. However, after I put it all back together, it's all returned. >> I looked the the S-meter, and with the RF gain set fully cw, I see the >> following brief readings that accompany the clicks and pops in the speaker: >> >> 15M, VFO A to VFO B: S1; >> *15M, VFO B to VFO A: S9; >> >> 15M-17M: S1; >> 17M-15M: click, no reading; >> >> *15M-12M: S5; >> 12M-15M: click, no reading; >> >> 20M-30M: click, no reading; >> 30M-20M: click, no reading. >> >> The other bands/VFOs switch quietly. >> >> Otherwise, the radio seems to work just fine, and has been performing well. >> I recently set 15M VFO B to 20MHz WWV, and that's when I noticed this. I >> wonder if I should just forget about it, except the S5 and S9 pops just >> don't give me a good feeling. >> >> How does the radio switch between VFO A and VFO B? I assume it's done in the >> firmware, but is some relay (or a band-specific relay) involved? >> >> > ______________________________________________________________ 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
