[time-nuts] Racal-Dana tactile switches

Jim bix at jimbixby.com
Sat Apr 5 16:53:24 EDT 2014


Ulrich Bangert <df6jb at ...> 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
> replacement.
> <snip> 


I finally had to dive into my Racal Dana 1992 counter, after it had 
developed several bad switches. I found that through-hole 6x6mm tactile 
switches with four leads will fit in the counter pcb holes diagonally. That 
is, if you trim off the leads from two opposite corners, the other two leads 
are very close to the required distance to go into the existing pcb holes. I 
just ordered some of these switches from ebay with a long plunger that looks 
to be perhaps 2mm round. I'm going to drill holes into the back of the 
existing keycaps to be a press-fit to the plunger on the new switches. I 
think it will all hold together. If this works, it is a cosmetically and 
functionally perfect solution. I'll report back after I've tried it.

The switches I picked are 6x6x10.5mm Tactile Pushbutton Switches, 
ebay item 161008571229, 

Jim






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