Thee are some differences in plugs, at least
And in how they ring
What is ring signal ?
The telephone company sends a ringing signal which is an AC waveform.
Although the common frequency used in the United States is 20 HZ and in
Europe is typically 25 Hz, it can be any frequency between 15 and 68 Hz.
Most of the world uses frequencies between 20 and 40 Hz. The voltage at the
subscribers end depends upon loop length and number of ringers attached to
the line; it could be between 40 and 150 Volts. The ringing cadence - the
timing of ringing to pause - varies from telephone company to company.
What telephone regulations say about telephone ringers
European NET4 telephone line terminal equipment specs define the following
specs for the telephoen ringing detector circuit.
a.. The impedance in voice frequency (200-3400 Hz) must be greater than 10
kohm when measured with 0.5V RMS audio signal
b.. The current taken by the ringer must be equal or less than 5 mA at 35
V ring voltage and equal or ledd than 10.7 mA at 75V ring voltage. The
measurments are made using 25 Hz ring current frequnecy.
c.. Ring detector must work on ring signal which is 44-58V DC summed with
25+-3Hz AC ring signal in voltage range 35-75 V. The feeding resistance for
ring generator is 800-1710 Hz.
d.. Ring detector must not detect ring signal which is 44-58V DC summed
with 20-3400 Hz AC ring signal which is less than 10 V. The feeding
resistance for ring generator is 800-1710 Hz.
If the equipment is automatically responding the equipment must wait at
least 1s from the ring detection until it goes off-hook.
Telephone ringer classification
In USA FCC regulations need the ringer type to be specified on the device.
The possible types are Class A and Class B. Class B ringers will respond to
ringing frequencies of between 17 and 68 Hertz while Class A ringers will
respond to betwwen 16 and 33 Hertz. Class A devices are those typical old
telephone bells and practically all electronic ringers are B type. Nearly
all of the devices made to connect to the phone lines today are of the Class
B type. The telephone ringer type on your device (if you live in USA) is
printed on the FCC sticker on the bottom with a REN number on it. You'll see
something like .9B (= REN 0.9 Class B) or 1.0A (= REN 1.0 Class A).
Forget Europe for now, Pop had said "pay phones" have different electrical
characteristics than "regular phones".
His claim, so its up to him to explain the difference between the two, if
Oh, that's different. Instead of a hard wired terminal, they use the metal
coins to make the contact. The coin drops down the slot bridging the two
wires. They are spring loaded to support the coin for three minutes, then
it drops and disconnects you.
Pretty sure most, ( if not all ) call supervision is being handled at the
exchange these days.....
Nonetheless, ring is gonna be at 20 or 25 hz, and then voice is on ~ 600
My point here being that doubtful any changes are needed whatsoever as to
outplant cabling and beyond depending upon whether it's gonna connect to a
pay phone or a regular phone (so far as I know)........
If push comes to shove, just so happens I live in a VERY small town....where
the local exchange is STILL privately owned....last I checked there are
maybe a dozen or so left in the US.....and all I gotta do if I got any
questions whatsoever is make one call and I get Gretchen on the line....her
great-grandfather had put the very first phones into this area many, many
years ago.......and if she dont know the answer, then she immediately
connects me to someone who does......
Any rate, (and as I said before)....its still up to Pop to explain the
difference here ( if any ).
Me thinks he was perhaps hittin the bottle just a bit heavier than usual,
and took to behaving like an ignorant lout is all.
More bullshit, I guess you never "pinned" a phone call.
All you had to do before the current crop of electronic pay phones was
short the tip to ground to open the originating register on a pay
phone line. It was done be sticking a pin in the cord and shorting it
to the frame of the phone. That was why they started using armored
cords. Then people stuck the pin in the mike or earpiece holes. Ma
Bell started using an armored element there too.
The caps are typically glued on.
I had a regular phone connected to a pay phone line at a pool I worked
at. (the fools had the Dmark in the lifeguard office) We shorted the
line with our whistle and got out fine.
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