Basically I want to make a "black box" with a single phone jack and an 1/8" stereo plug that can take the signal from a walkman and send it to a phone. Obviously the phone would only be connected to this box, not an outside line. Any ideas? I've done some google searches and haven't found anything promising.
Did it once.....real simple crcuit......can't remember details, but basically a NPN drawing 2 mA or so across the line, put audio on the base. Something like that.
Ask Harry, he has spent more time on 'phones. Just don't tell him I told you to. [joke]
Jocko
Ask Harry, he has spent more time on 'phones. Just don't tell him I told you to. [joke]
Jocko
Search the Web under POTS phone, for Plain Old Telephone Service. We used to use a feeding bridge to run audio to a phone, but we needed to supply DC voltage as well and maybe you won't have to.
BAsically you should use a transformer to feed the line, in series with a cap of 1-2 uF. Since you are using a 'phone as receiver, a small driver trafo from any old transistor radio will probably do, any decent line transformer will be excellent.. Feed from the walkman with a series cap.
Your 'phone will need to be powered though, usually from the line.
Try a 9-12 V from a battery pack connected to the 'phone side of the trafo /cap combo. Try 1kohm in series with the battery in order not to quench the audio....
Your 'phone will need to be powered though, usually from the line.
Try a 9-12 V from a battery pack connected to the 'phone side of the trafo /cap combo. Try 1kohm in series with the battery in order not to quench the audio....
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