[SML] Tele-Q & Practical Phones

[Mt. Angel Performing Arts Center]

On 11/19/2014 5:11 PM, Nigel Worsley via Stagecraft wrote:
> Frank Wood wrote:
>> Telephones still meet very old-fashioned standards, and sometimes
>> expect to see big relays across the line. I would think that 100mA
>> would be typical.
>
> Electronic exchanges typically feed the line with a constant current
> of 25mA, and because it is considered a reasonable scenario that two
> handsets will be lifted at the same time ( eg. for transferring a call
> by shouting at someone else in the house to pick up the other phone )
> it is a requirement for phones to function correctly on 12.5mA in the
> UK, and similar specifications exist in most other countries.
>
> Much older telephones have similar characteristics, as the 50V feed
> voltage and much of the sometimes very long wiring hasn't changed over
> the years.
>
> Nigel Worsley
>

I think what y'all need for getting a live phone line from point A to 
point B is what's called a 'telephone line simulator'. We used one long 
ago in developing a modem product and the reasonably good ones simulate 
a telephone central office and generate all the voltages and tones 
really well.

As I recall, we had a TLS-2 from Teltone, but they are now ridiculously 
expensive.

I have not tried these but have purchased other stuff from this seller 
and had no problems. see <http://www.sandman.com/simulator.html>

Carla

Feds have looked into our phone records, computers and e-mails. When did 
the government suddenly become our psycho ex-lover?