Hi Pete, I had a similar set of symptoms with my K3 several years back. Turns out it was not the K3 at all, but a failing filter capacitor in my linear regulated power supply. I had sporadic audio dropouts after transmitting in much the same way as you described, always at QRP TX levels.
Try a different power supply of newer vintage. I tested the ESR of the filter capacitors in my supply and found it to be much too high. 73, Mike, K8CN ________________________________ From: RFI <[email protected]> on behalf of Pete Smith N4ZR <[email protected]> Sent: Tuesday, November 7, 2023 10:31 AM To: Elecraft List <[email protected]>; RFI List <[email protected]> Subject: [RFI] HI CUR warning on K3 CAUTION: This email originated from outside of the University System. Do not click links or open attachments unless you recognize the sender and know the content is safe. I send a few characters of CW into my Carolina Windom on 40M and after a delay (1-5 seconds after I stop sending) the K3 flashes a HI CUR warning, and the audio gain is reduced significantly. Touch the AF gain control and it instantly returns the gain to normal, but frequently the HI CURR warning returns over and over, without any additional transmissions. This sequence does not happen, even with 1500 watts, into my dummy load, nor does it happen on the same antenna on 80M, or on 20 meters on my tribander. I've read the HI CUR warning discussion on page 65 of the manual, but it doesn't seem relevant, because I don't have external speakers. The fact that it only happens when feeding an actual antenna on one band suggests RFI, but the fact that the HI CUR warning and gain reduction recur again and again long after any RF has me puzzled. Any suggestions gratefully accepted! -- 73, Pete N4ZR _______________________________________________ RFI mailing list [email protected] https://nam12.safelinks.protection.outlook.com/?url=http%3A%2F%2Flists.contesting.com%2Fmailman%2Flistinfo%2Frfi&data=05%7C01%7Cmike.carter%40unh.edu%7Cfb5c2dea1c504cf20cfa08dbdfa6b4b0%7Cd6241893512d46dc8d2bbe47e25f5666%7C0%7C0%7C638349679330548847%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=bo1Yz5uyXwXNO21bur5fVt7fV1Y22Zsocg5KMjAI%2FwU%3D&reserved=0<http://lists.contesting.com/mailman/listinfo/rfi> ______________________________________________________________ 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 Message delivered to [email protected]
