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Hints, Tips and Solutions (Do NOT post requests for help here) If you have any useful general hints and tips for vintage technology repair and restoration, please share them here. PLEASE DO NOT POST REQUESTS FOR HELP HERE! |
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3rd Dec 2016, 12:57 am | #1 |
Nonode
Join Date: Oct 2014
Location: West Midlands, UK.
Posts: 2,181
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Pulse Dial Speed Checking.
NOT a very accurate method, but possibly helpful to newbies is the old tried and tested in the field method. I found it reasonably accurate on the older types of Strowger exchange. But that was after I'd calibrated my self against a dial speed tester.
1) Insert finger in "0" hole. 2) Release dial and start counting at a resonably pace -100 1000 and1. Dial should stop when you reach the last ( i.e 1 digit, approximately 1 sec after dial release( but this was done in the field) in the days when watches were not exactly reliable on second timing). Most possibly familair to ye ancient GPO/PO(T) blokes). |
3rd Dec 2016, 7:30 am | #2 |
Dekatron
Join Date: Jun 2015
Location: Biggin Hill, London, UK.
Posts: 5,188
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Re: pULSE DIAL SPEED CHECKING
Yes, I do that when looking at second-hand telephones in junk shops, etc. It gives a good idea if the dial is running at about the right speed, or if it is gummed up and running far too slowly.
I am told that these days you can sample the dial pulses with a computer+soundcard and look at the speed. Personally I either use a Tester 422/1 if I need it approximately, or a logic analyser to get it accurately. Mainly because I have both on the bench anyway. As an aside, a friend of mine bought a German telephone. Tucked inside the dial mechanism was a strip of paper which turned out to be a pen recorder trace of the dial pulses (presumably from the time the thing was made). |