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Telephone Headset mod

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Rich

New Member
Hi

I got this idea to build a little switchbox so that I could listen to the radio
when I was not on the phone.
My first prototype worked fine on my phone at home but not the one at work.
I just built a box with a manual DPDT switch that switched between phone audio and an external input.
It has two jacks for headset in and out to phone.
My phone at work is a Meridian model that i geuss has some smarts in the input jacks and it diverts to the speaker phone as soon as I plug in my box. Impedance issue?
I can hear audio (radio) through headset if I just have that plugged in and not the phone end. So I think my wiring is right.
Can anyone suggest a way around this?
I know next to nothing about phones so any help is appreciatted.
Thanks
:?:
 

Gene

New Member
Perhaps you could be a little clearer. You mentioned a telephone headset (implying a mic and a speaker), a phone (another mic and speaker), a speaker on your phone, and a radio (another speaker?). Maybe you could reply and attach a little jpg file of your circuit box.
 

Rich

New Member
More info

Hi
I have attached a humble schematic.
It is a PDF file.
I hope this makes what I want to accomplish clearer.
To summarize: I want to switch the headset earpiece to another
source (radio)so I can listen to music when not on the phone.
I find with this circuit will not work with my office phone,
so I think I need an alternative circuit that will not "load" the
input jack of the phone.
 

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Gene

New Member
I suspect there is a mis-match between your radio and the phone system - the schematic is OK. First off, you might want to replace the switch with a DPDT type and switch both the hot and ground rather than just the hot lead - you have two different grounds (phone and radio - not necessarily the same potential. Secondly, if you still have a mis-match, you could try to isolate the radio output by putting a capacitor (0.01/0.05 - whatever you have handy) in the hot line to isolate DC.
 
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