Kellogg 925 feedback problem

[unbeldi]

Perhaps we should first understand more clearly what Tina, or her callers, mean when they report "echo".
Echo usually means that someone receives their own audio back after some delay from the remote end, i.e. across a telecommunications network.
How long is the delay ?
This would mean that Tina's telephone feeds some of the received audio back into the network.

A single primary induction coil winding and transmitter in the local loop would not do this.  So, it has to do with audio "amplified" in the tertiary winding and this indeed could feed back into the network as it is across the transmitter.
We now have two ways to damped this extra current.  Indeed, dsk's method would introduce extra resistance and reduce the extra current. More dramatic would be to simply disconnect that wire from the induction coil.  This eliminates anti-sidetone correction as well, as previously stated.

The other way is to reduce the resistance of the transmitter.  Old transmitter carbon granules often suffer from cohering.  This is why I suggested trying to change the transmitter.

[cloyd]

The other night, a teachers union rep called to make sure that I had voted and she said that she was getting a lot of echo.  If my memory serves, and it frequently doesn't, when I have called home I didn't get that problem so it may indeed be that particular caller.

I will try to sub out the transmitter with another.  That sounds like the easiest first thing to try.  This is hard for me to test because I am home sick today with no one to call me on their cell phone from another room.  Perhaps this afternoon once hubby gets home.  I'll let you know my results later today.

Tina

[Phonesrfun]

It may not even be at your end!  The person calling you may have been using a voIP line or a cell phone.  Just because someone else hears an echo is not a reason to just assume that because you are trying out a new phone that it would be your problem.  I would say that it is a network problem (not associated with your phone and your Panasonic).  Also, people making telemarketing calls tend to use the cheapest and worst commercially available circuits.  Your teacher's union might have hired a telemarketing firm to make the calls on their behalf because an average teacher's union is probably not equipped to make massive calls on a daily basis.


The phone system out there these days has so, so many ways of causing noise and issues.  I think we have gone backwards in terms of quality.

[cloyd]

It may not even be at your end!  The person calling you may have been using a voIP line or a cell phone.  Just because someone else hears an echo is not a reason to just assume that because you are trying out a new phone that it would be your problem.  I would say that it is a network problem (not associated with your phone and your Panasonic).  Also, people making telemarketing calls tend to use the cheapest and worst commercially available circuits.  Your teacher's union might have hired a telemarketing firm to make the calls on their behalf because an average teacher's union is probably not equipped to make massive calls on a daily basis.


The phone system out there these days has so, so many ways of causing noise and issues.  I think we have gone backwards in terms of quality.

Very interesting!
Thank you!  I hadn't thought of that.
Tina

[poplar1]

If you have a cell phone, call it from the Kellogg and leave a voice mail. Then listen to the message.

[unbeldi]

If you have a cell phone, call it from the Kellogg and leave a voice mail. Then listen to the message.

Well, that only tests a small part of the potential problem, and most likely not the time when echo would occur.  Echo happens, if we understand the report properly, when the remote end is speaking, not when Tina is speaking.

[dsk]

I would like to ask you to read this commercial article from the text : Interfacing analog lines (or telephones) with VoIP phone systems
You may read it here: http://www.sandman.com/EchoBull.html
I do not believe you should buy some expensive gear to try if you could solve it, but it gives some ideas of what may be the the issue.

dsk