Mic Hand No.13
 

Anyone have a lead on where I could find an operational voicemitter for the Mic Hand No.13, or know how I can take mine apart and repair it? I have good continuity with everything otherwise.

ZA 17605 by any chance, James? Round, black, Bakelite, hockey puck thing with a thumb Pressel on top centre?

Should be three screws on the back. Two large lowers and a smaller top dead centre one that “I think” secures the Pressel assembly in place. Try removing the lower two and see if the rear cover just lifts off. If not, then loosen the top screw a couple of turns only and see if the cover loosens at all. If it does, then carefully remove the top screw and slowly lift the cover, paying close attention to the Pressel Switch area. You want to be certain of what you are dealing with: ideally a complete, self-contained switch assembly and not a bunch of separate parts all held in place by the cover and screw.

Typically, the mic element should just lift out, once you have the case open. Post a photo(s) of the element so we know what you are dealing with. I think this mic is a very late war production item, but not at all sure of the by whom and for what stuff.

David

Here’s the mic I’m using. I think the voicemitter is the same, although mine isn’t marked. I get noise in my ear pieces, but no side tone. When I push the pressel switch, I can hear the radio key up, so my best guess from my RTO days is the voicemitter has gone bad. I’m using a No1 MkII switch box in my set up. I read where certain mics won’t work with certain switch boxes, but I can’t find that info.

OK James. What you have there is a HEADGEAR, Assemblies, Cdn Type 10. They were standard issue in 1944 with the Wireless Set Cdn No. 52 but would interchange with most available 19-Sets Mk III. I am not certain if they will behave well with a 19-Set Mk II.

I pulled the element out of a working mic I have on my 19-Set Mk III. The resistance reading I get between the centre contact on the bottom of the element and the case is 41 Ohms once it settles down. If yours reads a similar, or close, value, try wiping down the lower section of the case and base terminal with alcohol and reinstall it. Connect the headgear to your 19-Set and turn it on and warm it up. Make sure you are in intercom mode and try speaking into the mic. You should be able to hear yourself in the Headgear.

David

I’d already done everything but without knowing the resistance value I didn’t check that. I show it to be open. My “extra” voicemitter shows open as well.

Hi again, James.

Thanks for dragging me away from my 52-Set Sender work for a while. It is at a point where I need a break.

You will need to find some replacement bits if both of yours are showing open circuit. What you are looking for is:

INSERTS, Microphone, Moving Coil, No. C1. ZA/CAN 0605

Geoff Turcott is a member of this site. Send him a Personal Message and he may be able to help you out.

David

As always, David. Thank you for all of your help!

One other thought on these inserts, James. You will find most of them lack the tape strip around the upper body. I have found this strip, and remnants of it, on Philco made Inserts and all of those came out of the Type 10 Headgear.

If you look at the Pressel Switch terminals inside the Mic Assembly, they sit rather close the the Inserts upper section. My thought is the tape is added to prevent the Insert from shorting the Pressel Switch, if the Insert should move for any reason.

I would suggest, to be on the safe side, add the tape strip to a new Insert, if you need to, before using it.

David

Will do. Thanks again.