Audacity Forum

I am using an RCA 4 line office phone, model #25423RE1-A; and a Radio Shack single line recorder model # 43-1237. Except for some minor weird dirt on the line my voice is recording perfectly, however the audio in my handset is not picking up at all. How is it possible that the line is separating the in & out and dropping the in when they are both traveling through the same line?

Recording from a copper phone line is magic -- particularly since most people don't just want their own voice, they want both sides and at the same volume.

Yes, both voices are on the line pair at the same time, but they're going in different directions. Equipment called Telephone Hybrids, Phone Patches, or Phone Couplers can split them apart and amplify each side differently. Any radio talk show features a bank of these things. A down side to the non-expensive ones is the need to manually adjust the cancellation -- the hybrid balance. You need to do that in order to insure separation of the two voices. Each phone call/line is different.

http://audacityteam.org/forum/viewtopic ... brid#p6891

This comes up regularly.

Most digital phone calls do treat the two sides differently and there have been people break into their cellphone and get both sides of the talk out.

Koz

Thanks Koz! Makes sense.