Bill, Be careful with silicone. Back in the 70's, give or take, it was discovered in a lab that silicone widely creeps and gets into electrical contacts and can cause circuit failures. The source was good. I won't let it in my house.
I have read that WD-40 does NOT contain silicone, but I don't know if that source was reliable. Some petroleum jelly w/o additives ought to be safe. A micro-switch works well, but it 'clicks'. If the PTT contacts are like other mics, you need a lever to actuate the contacts. Plastic PTT lever/buttons are rigid. Something flexible like rubber, or vinyl tubing could be devised perhaps. Maybe something like a soft ear-plug moving through a lubricated tube as a crude example. As I have said, I haven't seen the MH2. If you saved the original parts, you could experiment w/o ruining the mic. I just wanted to caution you about the silicone warnings. It could lead to big problems. Rich, n0ce ----- Original Message ----- From: "Bill" <[email protected]> To: "Richard Fjeld" <[email protected]> Sent: Monday, November 12, 2012 6:12 PM Subject: Re: [Elecraft] K3 - MH2 mic switch mechanical noise > Thanks Rich for the kind reply. I am looking at ways to re-engineer the > MH2. Basically, it involves a very cheap switch and plastic sliding on > plastic. Two distinct problems. > > I am working on using bubble switches as replacements and have tried a > silicone lubricant. > > I expect the combo of both tactics will relieve the problem. > > Thanks again, > > Bill W2BLC > > > > On 11/12/2012 6:18 PM, Richard Fjeld wrote: >> Bill, you said in part: >> >>> It is a mechanical problem within the mic, as other mics do not do this. >> >> You are partially right. The word is *SOME* mics do not do this. I >> have had both hand-mics and desk-mics do it. AND, it was not only a >> spike; it was during transmit if I changed the pressure on the PTT. The >> buttons should be soft material. Yes, it is annoying. It is one of the >> reasons I went to a boom-mic (CM500). No way for a mechanical noise >> pickup from a detached PTT. >> >> Now, it is so quiet I get complaints that my rag-chew group can't tell >> when I release the PTT. (Longevity affects the hearing.) I wrote in >> awhile back at their request to see if the K3 could do a short 'dit' when >> I released the PTT. (That opened up a can of worms) >> >> I don't know what the innards of the MH2 looks like, but you may try to >> improve what the element is cushioned in to reduce the microphonics. If >> it is audible noise, the electret element will 'hear' it. >> >> Rich, n0ce >> >> >> ----- Original Message ----- From: "Bill" <[email protected]> >> To: <[email protected]> >> Sent: Saturday, November 10, 2012 9:55 AM >> Subject: [Elecraft] K3 - MH2 mic switch mechanical noise >> >> > ______________________________________________________________ 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
