Adding 1/4" output to telephone handset

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Adding 1/4" output to telephone handset

Hello,

I just added a 1/4" output jack to a telephone handset to be used as a microphone but am experiencing some problems. What I did was take out the rj-45 connector and connect the positive and negative connections on the microphone element right to the jack. The microphone only works correctly when the element is exposed and I touch the positive contact with my hand. This is quite strange and I don't know what could be causing it. Does anyone have any suggestions? thanks.
 
I am trying to plug it into a guitar amp. I actually tested it with a 9volt battery wired to it and it worked fine. However, what I cannot understand is how it works without the battery when my hand is touching it, but will not work when I put it back in the chassis. I think it is an electret mike. Are these usually powered by internal circuitry that gets juice from the phone connector? thanks.

RJ
 
RJSkypala said:
I am trying to plug it into a guitar amp. I actually tested it with a 9volt battery wired to it and it worked fine. However, what I cannot understand is how it works without the battery when my hand is touching it, but will not work when I put it back in the chassis. I think it is an electret mike. Are these usually powered by internal circuitry that gets juice from the phone connector? thanks.

RJ

Yes, it gets it's power down the connector lead, have a look


here for examples!.
 
telephone

I don't fully understand telephone circuitry but was commissioned to do a telephone talk show to be recorded and later broadcast (radio caroline).
I tried everything with the phone and eventually bought a telephone interface and used it with mixing console. The only other solution that worked pretty good was using an Aopen FM56 fax/modem and routing it to soundcard.
 
I'm curious - why are you doing this?
If the 'phone's still on the network, it's almost certainly against regulations to connect peripherals this way, and there are easier ways of going about it. OTOH, if it's as a prop of some sort, why not just fit the handset with a suitable mic capsule (cheap computer mic, maybe?) which you know works OK.
BTW, if you're trying to get 'telephone' type bandwidth restriction as a special effect, this won't work - phone mics are relatively good these days - the filtering is done in the network. It can easily be reproduced in software or hardware though.
 
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