WECo 2500MM Side Tone

[Stan S]

Ralph

When you add series resistance on either side of a phone line and use any model phone with a REAL NETWORK (a 500 or a 2500) plugged into the line AFTER the series resistance, the side tone in that phone will increase and the incoming audio will decrease.

A phone with a 101 coil such as a 302 or a 5302 behaves differently. If series resistance is added between either side of the phone line and the phone BOTH the side tone and the incoming audio will decrease.

When you add series resistance between a phone line and a phone, as the series resistance goes up the loop current goes down and the off hook voltage across the phone line increases.

I doubt that anyone will refer to the number of a BSP that discusses this issue because to my knowledge adding series resistance between a phone line and a phone isn't done in the telephone industry for any reason. However, it is done in other 'industries' for various reasons. A story for another time.

If you own a volt meter you can perform an experiment. Put the meter across your phone line anywhere EXCEPT at the jack where the phones that had the high side tone were plugged in. Note the off hook voltage when you lift a test phone plugged into any jack in the house except the 'suspect' jack. Then take the test phone, plug it into the 'suspect' jack and take it off hook and note that off hook voltage. I'll bet you the second reading will be much higher than the first.

Bottom line is you have some series resistance between the 'suspect' jack and the rest of the house. Don't know if it was done purposely (for whatever reason) or by accident. Probably depends on who owned the house before you. Anyway, if you find and get rid of whatever that series resistance happens to be, you won't have to 'choose' the model phone you use at that jack.

Stan S.

[rp2813]

Stan, thanks for the explanation.

Even if I did the voltage test, I'd not know how to zero in on the problem to fix it. 

I do have inside wiring coverage from my local exchange provider.  Maybe I can pursue this through them.  I'm fairly certain that this situation was intentionally created by the tech who was out to resolve the DSL issue several years ago.  It's worth a shot.