[time-nuts] Racal-Dana tactile switches

[Ulrich Bangert]

Gentlemen,

I know I am not the only one in this group to have difficulties with "weak"
tactile switches on Racal-Dana's 1991/2/6 range of counters. The other day I
talked to the chief technician at Rosenkranz-Elektronik which is one of the
biggest surplus suppliers in Germany. 

He knew the problem very well and his claim was that an exact replacement
for the original Toko switches is no more produced anywhere in the world.
Which may be an explanation why none of us managed to find an exact
repelacement. 

His second claim was that the switches can be repared: After removing the
cap gently grip the moving part with  a pair of pliers and twist it a little
bit while pulling it out a bit at the same time. In this way the moving part
can be removed without destruction of the switch. Then you find the source
of the problem inside: The weak and mostly destroyed rubber part inside.
Replace it with the rubber part of a switch which has NEARLY the same
dimensions. He told me that he had done such a repair for a number of times.
Unfortunately he had no reference for the switches that he had used as the
source for the replacement rubber. 

I am aware that this is only half of the solution of the problem but I
checked his suggestion with a original switch that I had laying around as a
replacement and found that his description worked for me. I made a photgraph
of the switch to be found here: 

http://www.ulrich-bangert.de/Racal.JPG

and perhaps anyone of you has an idea where to get a similar one from. The
problem to find a similar switch is perhaps easier to solve than to locate a
direct replacement. Note that the scale in the photo is in cm with
subdivisions in mm.

Best regards

Ulrich Bangert
www.ulrich-bangert.de
Ortholzer Weg 1
27243 Gross Ippener