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and very rarely ever needs repairs, once you fix them." - Dan/Panther

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Reihenapparat S 11 - 121 / 1 H

Started by dsk, May 15, 2022, 05:06:02 AM

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Mine is made in 1937, but I beleieve thos were made from 1933.
I got it for free for use as parts, but it is an interesting circuit.
I found more info about it here:

I have tuned the dial as good as I could, but the metering shows wrong from the phone. It actually work on my 1940ies exchange, but....
So what could be wrong. The breakes became shorter, but they are there....
I disconnected the only thing that I see that could ruin pulse, the capacitor+resistor actoss the NSI pulse contacts, and it worked. Seems slike the capacitor is bad.

Haw accurate is the readings? I will say that it may be within one desimal digit.
How stable is a mechanical dial from 1937 that has got a minimum of maintainence?
I guess the readings om the pictuere may be accurate enough.


I suppose the dial testing software is quite precise measuring the pulses. It clearly can be seen that the pulses aren't equally long. Cleaning the mechanism and especially the contacts might help.
I have good experiences with the use of auto brake cleaner for cleaning old style metal dial mechanisms. It will take away old sticky grease. Then I normally apply WD40 very sparingly with a toothpick or a tiny paintbrush. I know the product is a no-go for many experts but from my experience has a good cleaning effect and leaves behind a non-gumming lubricant.
For the contacts I use Kontakt 60 contact cleaner.
The shop (a good supplier for W48 and other classic German parts) carries small suede covered sticks which work very good for contact cleaning. A cardboard slip will also work.