EDIT: Don't be confused when I say "L/C" but express the values as "C/L." You know what I mean ...
-----Original Message----- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Lyn Norstad Sent: Tuesday, July 06, 2021 3:48 PM To: Elecraft@mailman.qth.net Subject: [Elecraft] KAT500 80 meter anomaly On 80 meters, the KAT500 stores frequencies in memory every 10 kHz. Because of bandwidth issues, normally that's a good thing. Except when it isn't. Many digital modes that use prescribed frequencies are clustered in a fairly narrow region. For example ("dial frequency" in kHz): FT8 = 3573.000 FT4 = 3575.000 Winlink 80m Gateway 1 = 3586.000 Winlink 80m Gateway 2 = 3595.000 If you only operate FT8 and FT4, there is no issue. Likewise, if you only operate Winlink in that region, no problem. But if you operate both, the KAT500 can't seem to recall the exact settings for any of those frequencies consistently. Here's an experiment for you to try, if you're interested: 1) Clear the frequency memory for 80 meters on whatever antenna you use (KAT500 configuration>Erase Antenna Tuner Memories). 2) Using the same utility, "Memorize" a setting for each of the four above frequencies. 3) Conduct a Winlink VARA HF session at both 3586 and 3595 kHz (if you can't connect to any stations, that's OK too). 4) Then using WSJT-X software, do a brief session using FT8 and then FT4. So far, so good. Everything works great. But now go back to the Winlink software are try to check for mail using the same frequencies, 3586 and 3595 (it would be nice to connect this time). If your system works like mine, on every other transmission it will hunt for a new match (even if it's already 1:1). In my case, the "normal" L/C values are: @ 3573 = 0 / 6500 @ 3575 = 0 / 6500 @ 3586 = 180 / 6500 @ 3595 = 180 / 6500 When the KAT500 goes a little bit crazy with its "every other time hunt" on the Winlink frequencies (3586 and 3595) it will jump to some extremely high SWR value (in the 80s or 90s) and then eventually settle back with an L/C of . say . 0 / 5400 (creating settings for 3592 kHz). Meanwhile, the Gateway station has very likely lost at least half of your transmission. This behavior is independent of Automatic or Manual settings, exciter power settings, KPA500 On or Off (but OFF is better for testing, for obvious reasons). Is there a Command that would help to alleviate this behavior? Or a way to tell the KAT500 to ignore one or more of its preset frequencies that are causing issues? 73 Lyn, W0LEN ______________________________________________________________ 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 l...@lnainc.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 Message delivered to arch...@mail-archive.com