I can duplicate what might be called QSK thumps with high volume settings and using earphones or speakers. I have the choke change but have not modified low frequency response with larger caps. I think the thumps come on key up not key down. Everything is fine when I have the volume set at a normal level. I begin hearing thumps at a volume setting of 11 O'Clock.
What I believe I am hearing though is not an artifact but just high band noise between dits that give an impression of thumps. The high band noise is being gated by TR switching. I suspect if I didn't live in a high noise environment I wouldn't here this. Mike Scott - AE6WA Tarzana, CA (DM04 / near LA) NAQCC 3535 K3-100 #508 / KX1 #1311 I sat down in TEST mode and tried all the combinations you mentioned again and can't produce thumps. I even tried every possible combination of AF/RF and MON levels with no thump. So I'm sri to say obviously something is different between our rigs and setups, but I can't imagine what. The only audio mod involving a change on the main board is to change a choke, not a cap. It reduces the resistance of the choke to improve the voltage regulation at the AF Amp. I've made that too. When I said my K3 was "stock" Elecraft, it does have the Elecraft-approved and documented mods made while writing the app notes. I asked wondering if the capacitor changes some have made to improve the low-frequency response were making the low frequency 'thumps' stronger and audible. If you've not done them, we should have similar rigs. Ron AC7AC ______________________________________________________________ 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
