UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > General Vintage Technology > General Vintage Technology Discussions

Notices

General Vintage Technology Discussions For general discussions about vintage radio and other vintage electronics etc.

Closed Thread
 
Thread Tools
Old 18th Sep 2021, 2:02 am   #1
Sparks
Heptode
 
Join Date: Oct 2006
Location: Leeds, West Yorkshire, UK.
Posts: 593
Default What type of microphone is this ?

It came today with a very old Airmed (before Clement Clarke) Airlite 70 headset. I'm familiar with the newer half-oval shaped microphones that clip on to the boom but I've not seen a round one before. There are no obvious part numbers or type descriptions on the unit. Thankyou.
Attached Thumbnails
Click image for larger version

Name:	20210917_162252.jpg
Views:	189
Size:	34.4 KB
ID:	241553   Click image for larger version

Name:	20210917_162316.jpg
Views:	147
Size:	29.8 KB
ID:	241554   Click image for larger version

Name:	20210917_162302.jpg
Views:	158
Size:	33.3 KB
ID:	241555  
Sparks is offline  
Old 18th Sep 2021, 9:15 am   #2
Radio Wrangler
Moderator
 
Radio Wrangler's Avatar
 
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,798
Default Re: What type of microphone is this ?

Some aircraft radios/intercoms used carbon microphones, some used moving coil. So headsets have long been modular with interchangeable microphone capsules. So you could have either Dynamic ones usually have their magnets screened, so waving one around near the panel doesn't upset the compass so you can't tell that way. Try it on a dynamic mike input on something and if you don't get a response, it's probably carbon.

David
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done
Radio Wrangler is online now  
Old 18th Sep 2021, 11:20 am   #3
Sparks
Heptode
 
Join Date: Oct 2006
Location: Leeds, West Yorkshire, UK.
Posts: 593
Default Re: What type of microphone is this ?

Thanks David. The size of it suggests it's either carbon or moving coil with a built-in matching amplifier to boost its output. I will test it eventually but I thought someone might have an idea in the meantime.

Interestingly, it came fitted with a PO610 connector, i.e. two x BPO phone patch plugs mounted side by side in a single casing. These used to be used in American ATC comms panels but I don't know of any particular use in the UK.
Sparks is offline  
Old 18th Sep 2021, 9:42 pm   #4
Sparks
Heptode
 
Join Date: Oct 2006
Location: Leeds, West Yorkshire, UK.
Posts: 593
Default Re: What type of microphone is this ?

I've tried it on a plain audio amplifier (no dc voltage bias) and got nothing. Tried it with 7.2v going through - it works. So either carbon or amplified dynamic or amplified electret.
Sparks is offline  
Old 18th Sep 2021, 11:36 pm   #5
Radio Wrangler
Moderator
 
Radio Wrangler's Avatar
 
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,798
Default Re: What type of microphone is this ?

If it's noisy, then it's carbon

Otherwise, anybody's guess.

DAvid
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done
Radio Wrangler is online now  
Old 19th Sep 2021, 9:30 am   #6
Sparks
Heptode
 
Join Date: Oct 2006
Location: Leeds, West Yorkshire, UK.
Posts: 593
Default Re: What type of microphone is this ?

Not overly noisy. I've just noticed it only has holes on one side so it's not likely to be a cardioid type either.
Sparks is offline  
Old 19th Sep 2021, 10:59 am   #7
Radio Wrangler
Moderator
 
Radio Wrangler's Avatar
 
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,798
Default Re: What type of microphone is this ?

Most aviation headset microphones have holes both sides and may even contain two elements for ambient noise cancellation. It might be for ground use (tower or radar op) or be for something with a quiet cockpit (jet, glider)

Glider pilots like using no headset, a speaker and then have the mike on a gooseneck boom. The makers of these use dynamic capsules. We did our radio transceiver for electrets as used in most David Clark headsets, so gliders were a problem and needed an inline amplifier.

David
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done
Radio Wrangler is online now  
Old 19th Sep 2021, 11:22 am   #8
Sparks
Heptode
 
Join Date: Oct 2006
Location: Leeds, West Yorkshire, UK.
Posts: 593
Default Re: What type of microphone is this ?

I might email Clement Clarke on the offchance someone there can identify it. It's about fifty years old so I'm not hopeful.
Sparks is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 11:25 am.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.