Just wired up a SSK for my Stryker and noticed it has noise when keyed. A hissing, rushing noise. I would appreciate ideas. Recap?? Here is a video of the problem.
Yes, it is, but the SSK is not electret. It's dynamic.Stryker isn't set up for an electret mike, is it?
Just a shot in the dark.
73
It's set for dynamic cuz I'm using a Plus Three on there now. I've used a mixer and headset, a D104, a Yaesu M1 reference mic and Turner plus threes all along. This particular mic makes the noise and if I talk into it it sounds kinda distorted and hissy. When I use the plus three I never fail to get Rave audio reports. People can't believe when I tell them what I'm running. But this one mic makes noise.A radio that's configured to use an electret mike is sending a DC voltage out the audio wire. If you can choose dynamic from the radio's setup menu, this might fix it. The SSK's cartridge is dynamic, but its output is amplified. The DC voltage feeding out of the radio upstream into the mike preamp's output circuit might be the culprit.
Maybe.
73
Yup, even shot cleaner in it and worked it. Getting loud background white noise when keyed. Now it only keys for about 10 seconds then quits.just curious,,,did you adjust the bottom adjustment. the little hole on bottom of mike?
Keying 10sec and quiting has nothing to do with board or components. 2 wires short through the switch contacts and key. So if the contacts are bad that would do it or something is wired wrong. The white noise could also be bad contacts. Or that little chip on the board if the caps didnt help.Yup, even shot cleaner in it and worked it. Getting loud background white noise when keyed. Now it only keys for about 10 seconds then quits.
Well, you know that and I know that. But it will key for about 10 seconds and then while the bar is still down, it unkeys. And it will refuse to key again until I let it sit for a minute. Then it keys. At first I thought the radio was screwed and the time-out was turned on or something, so I went back to my Pluss Three. All is well. Went to the SSK and again, keys for 10 seconds and then unkeys until it sits for a minute. Contacts are like new, in fact, the entire mic is like new. Just keys funny and sounds terrible.Keying 10sec and quiting has nothing to do with board or components. 2 wires short through the switch contacts and key. So if the contacts are bad that would do it or something is wired wrong. The white noise could also be bad contacts. Or that little chip on the board if the caps didnt help.
Well, maybe I can. But it's going to take two hands to run my meter and then somehow got a hold the key down quickly because it'll unkey itself in 10 seconds. I'll take it back apart again next week, didn't want to leave it laying in Parts on the bench because those parts always seem to have legs. I'll check on the voltage drop when it's keyed and see what's going on there.Maybe a noisy/faulty transistor in the amp circuit causing the rushing sound or drifting resistor causing it to be biased incorrectly? I have one here, I will find the schematic and take a look.I'm curious if it employs a keying transistor.
Edit, no, no keying transistor, but that mfc4000b IC is a possible noise source. Can you monitor battery voltage/current while keyed?