I made a successful repair of a Racal 1991 counter that I originally bought as a spares unit, the original switches and switch caps had already been removed and discarded, but decided after all that it was too good to just use for parts, especially as all that ever seems to fail anyway are the switches:-) As I believe others have also suggested I found that 6mm square tactile PCB switches could be modified to fit in place of the original Racal switches. Refitting the original switch caps wasn't an option for me, but whilst trying to devise some convenient method of operating the normally very squat PCB switches through the front panel I came across some switches on Ebay with extended actuators. Using a switch with an overall height of 13mm allowed the actuator to protrude approximately 3mm through the panel and this works remarkably well. It's obviously not totally ideal, one downside for many would be that the keypad numbering is normally only on the switch caps, although I was lucky with this unit and the numbers were part of the panel markings, but it did restore the 1991 to being a perfectly usable counter. However, given that most users contemplating something similar would probably still have the original switch caps, and that it shouldn't be too difficult to refit these to the longer actuators, I think such switches might provide at least one answer to the problem. Anyway, I've written up a few notes to go with some photos I took whilst fitting the switches to my unit and have uploaded these to Rapidshare just in case anyone might be interested...... _https://rapidshare.com/files/1424161401/Racal1991Switches.zip_ (https://rapidshare.com/files/1424161401/Racal1991Switches.zip) Please feel free to share or bin this as you think fit:-) Regards Nigel GM8PZR -------------------------- In a message dated 21/04/2012 11:22:03 GMT Daylight Time, df...@ulrich-bangert.de writes:
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 _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.