🚀 go-pugleaf

hi hi hi,

I have a few telephone electronics questions maybe you can help me with.
I want to sit on the phone line and look for DTMF (dual tone multi-frequency)
signals.  My current circuit works by using a low impedance (8 ohm)
audio 8:1000 transformer in series with the tip line.  The ring line
remains untouched.  My circuit looks at the high impedance side of the
transformer to read the signal.

Question 1:  Is my transformer component choice a good one?

Question 2:  Is there is solid state component that would perform
the tapping and isolation function that the transformer now performs?

Question 3:  What precautions should I take on my circuit side regarding
the high voltage ringing signal passing through the transformer?  Are
diode shunts enough protection?

Thanks for your help.

Rich
drewes@cory.berkeley.edu