Terryphone help please

Hello all,

I am a bit stumped with the age of the equipment and the serious lack of any docs. Like it zero docs.

All I have is the following:

ITT Terryphone C23047 0100 Amplifier.

Connected to multiple speakers that are labeled D31201-0500 VRC8 with a multi-tap Txfmr L50411-0010.

What I have determined is that the Amp is a 100 Watt unit.

What I can't find is this at 25v 70v or 100volt.

The only reason I think it is a 100 Watt unit is the 0100 in the part number. However it could mean 100 volt system.

Can anyone shed some light on this. It is not for repair of the system that is rapidly going away, rather it is to determine the size and voltages of a new Amplifier that is to be installed.

I hate shooting in the dark. With the amount of dark I have right now any glimmer of light would be a blessing.

Please respond.



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If you don't find help here you might also try the comp.dcom.telecom newsgroup. Quite a few retired or non-retired techs there that might just have some documentation on it squirreled away.

Just remember to append [telecom] with the brackets to your subject or it will get blocked by the filters.

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Thanks for the input. Will post and thanks for the tip.


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Wire_les had written this in response to

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: That Terryphone amp is 70.7 volts. It probably has a 600 ohm input to be used by analog telephone circuitry.

Tap all your speakers at 1 watt and theoretically the amp will drive 100 speakers.

You can increase the volume at a given speaker by setting the tap at a higher wattage. If I remember correctly the tap settings are 1/2.5/10/Line

BTW, If one speaker is wayyyyyy louder than the others it's usually because the louder speaker is set at line (70v)voltage...it will draw everything the amp has to offer leaving nothing for the remaining speakers.

Terryphone was headquartered in Harrisburg PA. It was founded by Kent Terry.

The basic Terryphone system was a simple party line PA/Intercom and was used in car dealerships, factories, truck docks, etc. It was all diodes and relays to create multizone paging systems.

To use: Pick up the Terryphone handset, click the handset "locator" (SPST) button to page the overhead speakers and wait for your party to pick up on another Terryphone handset. "Joe, Pickup Terryphone Line 1".

Terryphone was purchased by ITT at some point. ITT incorporated the Terryphone system into their 1A2 multiline office telephone systems. That way the office user could page the plant/dock/warehouse from their desk phone and the basic TerryPhones could be installed/used in places where you didn't want a multiline phone.

Good luck!


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