For us old timers, it sounds like a crackly vacuum tube (not microphonic) but a crackling mixing tube in the eye of chain
I don't recall the exact mixer in the old Drake r4c series, but it was a common occurrence happening about 1 out of 3 times which caused one to have a box of tubes using them to substitute until you could find one that was quiet Rob Sherwood designed a solid state mixer circuit that many Drake users purchased to eliminate this problem Jim W6AIM -------- Original message -------- From: Jim Bolit <jbol...@outlook.com> Date: 11/30/2015 7:32 AM (GMT-08:00) To: elecraft@mailman.qth.net Subject: [Elecraft] Fwd: Crackling in Headphones Nope, not on mine. It also occurs when the antenna is completely disconnected. I have spent hours troubleshooting this to determine the source of the problem and in my case it is clearly inside the radio. Jim W 6 A I M . -------- Original message -------- From: "zabarnick ." <zabarn...@gmail.com> Date: 11/30/2015 7:08 AM (GMT-08:00) To: elecraft@mailman.qth.net Subject: Re: [Elecraft] Crackling in Headphones Could this be the AF limiter kicking in on loud signals? Check the "AF LIM" menu setting. Steve N9SZ On 30 Nov 2015 14:02, j...@kk9a.com wrote: > There are times that I have noticed a crackling sound in my headphones > with my K3S. This is not the normal band noise static that has depth, this > crackle sound seems very close to my ears. I first noticed it with my > Heil headset and I tried wiggling the connection, changing the RX EQ > settings and turning on noise reduction but nothing had any effect. It > randomly comes and goes and I think I have also heard it on TX. I thought > perhaps it was related to the Heil brand headphones. Last night I plugged > in a new Sony professional headphone and the crackling sound was very > strong for a few minutes and then eventually went away. I have never > experience this with any other radio and I have no idea what is causing it > or how to make it go away. > > John KK9A ______________________________________________________________ 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 jbol...@outlook.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 jbol...@outlook.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
