[GreenKeys] Teletype near Toronto

[Bill Horne]

On 04/27/2011 12:15 PM, Jim Haynes wrote:
> On Wed, 27 Apr 2011, densmore at kaponline.com wrote:
>
>> Price is right.
>>
>> http://ontario.kijiji.ca/c-buy-and-sell-electronics-Old-Style-Teletype-Machine-W0QQAdIdZ270451876
>>
>> Keith VE3TS
>>
> And it's the private-line model preferred by old computer restorers.

I'm curious: did the private line model use electronic line current 
sensors, or where there polar relays in them? I trained on Model 32/33 
in 1976, but the class just barely covered the electronics: I remember 
there was a transistorized driver for the selector magnet, which took 
several hundred milliamps, but that's all they taught us.

I know they could be strapped for 20 ma current loop, and probably for 
60 ma (they say the memory is the second thing to go), but I never 
worked on a machine that was actually in use for private line: ours had 
20 ma <> RS-232 converters on them, and they were attached to DEC computers.

Bill, W1AC

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