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Old 30-Aug-2015, 8:32 PM   #19
rabbit73
Retired A/V Tech
 
Join Date: Aug 2012
Location: S.E. VA
Posts: 2,753
Keep in mind that an incoming call will send about 100 volts AC for the ringer. The DC voltage to operate the phone is about 50 volts DC on-hook. When you pick up the phone the off-hook voltage is much less because the phone is drawing current. It probably will not appear on the ground wire when you are making the connection, but in case it does, I want you to be aware of that possibility.
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