> For maximum power transfer load must match generator. 

Don't confuse the audio power transfer, with the DC issues.
The DC resistance of the telco set can be quite low, and yet keep 600
ohm impedance. Terminating with 600 ohms resistive will get you a set
that won't show off-hook on a long CO line.

> It is not
> practical to invest too much in this, however, so real life ballpark
> values can be used. Phone lines loaded about as much as one dares in
> this sense of the phrase go to about 12V at 20-30mA drain. If you are
> directly connected to the pbx (2 meters of cable) you can draw 50+mA.

Closer to 100mA  In France, they want you to draw 100mA.



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