Author Topic: carbon microphone replacement  (Read 3118 times)

Offline dsk

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carbon microphone replacement
« on: March 23, 2016, 07:16:46 AM »
I have never tried for real before, but todays experiment seems to work.

I used a diode to short out the unit if the polarity gets wrong. it works from approx 4volts, and it has only 5 components.

enclosed pictures:

dsk

Offline Jack Aman

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Re: carbon microphone replacement
« Reply #1 on: March 23, 2016, 10:52:03 AM »
I have five "daily drivers" deployed and use them constantly.  Three D1/202's and two 302's.  The carbon transmitters in all of them (three F-1's and two E-1's) have been replaced with amplified electronic mic/transmitters.  Not good I guess from a purist/collector point of view, but a vast improvement in functionality while keeping the "stock" look.  My callers say incoming voice is astonishingly clear.

Offline dsk

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Re: carbon microphone replacement
« Reply #2 on: March 23, 2016, 11:03:25 AM »
I had a hope of getting this working on a LB phone with 3V battery, but, no! I need 3 elements. Well it works! :-)
dsk

Offline dsk

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Re: carbon microphone replacement
« Reply #3 on: March 23, 2016, 01:18:27 PM »
Sharper photos, I hope.
dsk

Offline Phonesrfun

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Re: carbon microphone replacement
« Reply #4 on: April 06, 2016, 01:08:20 AM »
DSK:


Pretty small unit.  Do you have a picture of the finished product in actual use?
-Bill G

Offline dsk

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Re: carbon microphone replacement
« Reply #5 on: April 06, 2016, 02:48:32 PM »
I have to try it out, and see if it really keeps on working.
dsk

Offline ThePillenwerfer

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Re: carbon microphone replacement
« Reply #6 on: May 11, 2017, 09:45:50 AM »
I tried this but found that it didn't work very well.  I'm not saying there's anything wrong with it, just that it's not suitable for my equipment.

I have however come up with a slightly more complicated version that works very well.  It's still simple enough to make 'dead-bug' style.

A zip is attached which contains PCB details.
« Last Edit: August 31, 2017, 07:02:27 AM by ThePillenwerfer »

Offline dsk

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Re: carbon microphone replacement
« Reply #7 on: May 11, 2017, 10:33:41 AM »
I had forgotten this thread, no it did not turn out as suitable for me. I might have used diodes with too high voltage drop, or done bad soldering, but no. No good! 

dsk

Offline markosjal

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Re: carbon microphone replacement
« Reply #8 on: May 16, 2017, 01:52:54 AM »
INTERESTING INDEED!

I was recently very curious about the "carbon Mic replacement" mics at payphone.com which would seem to fit in a 500 handset. This means I can test this with the F1 as well.


Mark
Phat Phantom's phreaking phone phettish

Offline dsk

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Re: carbon microphone replacement
« Reply #9 on: January 04, 2020, 02:32:38 AM »
I have found some replacement capsules: http://www.classicrotaryphones.com/forum/index.php?topic=23321.msg233918#msg233918
But for phones that operates on low voltages, they are not suitable. 
Most field telephones and local battery telephones may have room for different batteries, so when changing transmitter it may be needed to change batteries.
Some older German phones has a current consumption in the sidetone balancing network making it difficult. Soldering in extra resistor+capacitor may solve it.  Then the question is. Is that change of the phone worse than only putting in an transistorized capsule?  It is reversible, but you need to solder.

dsk
« Last Edit: January 04, 2020, 02:39:24 AM by dsk »

Offline 19and41

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Re: carbon microphone replacement
« Reply #10 on: January 08, 2020, 05:12:35 PM »
One of my jobs at the transit authority was to build handsets for the train communications systems.  I had to sometimes find sources for the components used in them.  I remembered one of them carried electret microphone cartridges to replace carbon cartridges.  Would any of these be of any value?

http://telephonecomponents.com/transmitters.html
"Any sufficiently advanced technology is indistinguishable from magic."
Arthur C. Clarke

Offline rdelius

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Re: carbon microphone replacement
« Reply #11 on: January 08, 2020, 06:55:23 PM »
At COT we would get a unit from Audiosears that was  similar to the EMS 94 on the link WE would replace the carbon microphone and cup in a G type handset. I would dissassemble the unit and use the printed circuit in tight spaces in some handsets

Offline dsk

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Re: carbon microphone replacement
« Reply #12 on: January 09, 2020, 12:25:14 AM »
Thank you for sharing more info.
dsk