Recording phone calls using a handset tap device on 8851.

[dbetz]

I have a group of people who need to be able to record their phone calls using a device, that attaches inline with the handset cord, on the 8851 phones.  We recently have upgraded them from 7945 or 7965 phones, where this device was working just fine.  When the phone was changed to an 8851, either the recorder picks up the phone side of the call fine or the other end just fine, but not both.  I have tried it personally with a different tap device with the same results.  I was not able to hear me, but I did hear the other side.

These phones are getting their power from the network switches and the controlling system is under the control of a third party.  I'm looking for any assistance that I can get to resolve this issue.  On a couple of the recordings I have personally heard, it is like there is a bad wire somewhere between the connection on the phone and the connection on the handset itself.  Different handset cords have been tried and different devices have been tried with no luck.  I'm wondering if there is a setting in the 8851 that needs to be changed or if there is not enough power to help power the tap.  Any ideas would be welcomed.

[SteveK066]

I wonder if the sidetone of the 79XX series phones is more audible than the 8851. If yes, that would be why you were heard and recorded with the 79XX phones, if the 'tap device' used the receive pair of the handset. There is no sidetone that I can hear on my 8851 or 7841 phones. Back in the TDM days, I'd just take audio from the receive pair of wires of the handset, were at least a low level of sidetone was present, so the user of the phone was heard. I don't think power has anything to do with it as the goal is to just connect to analog audio in the phone. If in fact sidetone can't be used, a more elaborate interface would be needed that would combine the microphone audio of the handset with the receiver into the recording input.