After noticing some noise problems with the MH-36b, a failed cleaning attempt leads to complete destruction, horrible problems finding replacement parts and finally a crafty (and desperate) fix using an old computer case switch.
Oh, and then Yaesu offered me a free switch 
When I first started using the Mic I was accused by some stations of cutting off half way through sentences. As they were mobile at the time -and kept cutting out on their input, I wasn't too worried at first.
Further investigation (trying to listen to my output on a mobile rig without feeding back too badly) showed that there was a lot of static coming from the PTT switch, so every time I moved my hand on the mic there was a possibility of it cutting out (the mic that is, not my hand).
I took the mic apart with the intention of spraying some IPA Solvent through the switch -though advice from #hamradio told me to just replace the microswitch. Easier said than done.
After 2 hours of searching the Farnell catalogue for microswitches and getting nowhere. I tried to pull what I thought was the mounting bracket off the switch. Turns out it was the other side of the switch casing and, long story shot, its never worked again. Saturday night and I've just destroyed my radio.
At this point I completely freaked out and did some more desperate searching. Not good news. I can't find a microswitch the same size, and certainly not with the same mounting (screw and peg). I went slightly spare after searching through pictures of switches and moved onto microphones.
The MH-36b is discontinued and doesn't exist on ebay. The only mic that I could find even close to it was a MH-48a. Same casing and buttons, but apparently different wiring on the inside. It also had a price tag of £70 or £25 from china. I don't have a spare £25 and I don't want to wait 6 weeks without a rig either.
I got a little bit desperate and started emailing any people with technical info on the mh36b microphone and also sent an email to Modern Radio (in Bolton) as I bought a dual-band antenna from their ebay shop and ended up going to pick it up in person. I have to say, it seems to be stocked by friendly and knowlagable people and they only charged me £12.50 for the ariel; they have my recommendation. The last email I sent was to Yaesu via their website telling them that I had the mic with the broken switch; could they please offer me a part to buy or tell me who can fix it; though as the website never seems to work properly, I didn't expect a response.
Sunday rolls round, and I'm installing Ubuntu on a friends computer, still looking at microswitches and lamenting how silly I'd been in making it all worse. Bob innocently asked why I couldn't just scavange a switch out of something else and in the middle of explaining I didn't have anything with a suitable switch, nevermind something that would be the right size, I finally realised he was a genious.
The mic actually has a lot of dead space in the back of it (opposite the PTT microswitch) and being a computer engineer, I have plenty of old case switches.
The PTT plastic is hollow, so after cutting apart and gluing a pen cap into the recess I made sure that the switch would fit in the cavety (bluetac is a wonderful thing). The only annoyance is that the switch is now going to be stuck onto the back cover of the mic, and the wires soldered to the board screwed to the front, but its a small price to pay.
It took three attempts with chemical metal to get the switch mounted properly. First I built up a flat platform (on the curved back plastic of the mic) for the switch to sit on but the switch came off. After a second failed attempt to make it stick in place I atleast had a nicely sculpted seat that it sat in snugly. I cheated at this point and superglued it in. After it set (and I checked it was working) I liverally applied more chemical metal to hold it all in place. I am slightly woried about the lateral sheer force, but hopefully the chemical metal housing will hold.
Everything seems to be working happily and (most of) my mic problems are gone. Hows that for a quick bodge! I'm just wondering how long its going to last now 
On Monday morning, I got emailed back from both Modern Radio and Yaesu.
Modern Radio said that they had been in touch with Yaesu and that due to minimum order price and postage it was going to cost £11. I thanked them but I'm a little upset that a 99p microswitch is going to cost 11 quid.
Yaesu also emailed me back (9:30am Monday morning) with an extremely short message:
Hi Daniel Please send SAE to address below and we will send a new PTT switch FOC asap.
This left me lost for words. On a 15 year old mic they have offered to send me a component for nothing. Yaesu, thank you very, very much. -I will be asking about my FT-60r rotary dial as well :)
In conclusion; not all big companies are evil, infact some actually seem to care about their customers. Saying that, it was £200 of radio in the first place, so I suppose in some ways they should care.
I hope this helps someone, or atleast gives you some ideas of things to do with broken microphones. I might have to try and fix the CB next... or maybe not.
73s
One of the Microphone images was grabbed from an ebay listing and the other from EurekaBoy.com all others were taken by me on my K800i.
