Racal Dana 1991 (and similar) frequency counter repair

[TheDefpom]

Hi All, I recently did a video on this, I found some momentary switches which fit pretty well, so if you have a 1991, 1992, 1998 etc then you might be interested in the video, I also have a link in the description of where to get the switches.

[David Hess]

I just pulled the switch tops out and cleaned the contacts on mine to restore proper operation.  The gold contacts had a white residue on them.

[edpalmer42]

It seems that all the switches in the 19xx Racal counters will eventually fail.  The 'rubber' membrane inside the switch fails and you lose the restore force that gives the switch its tactile feedback and keeps the switch open.  The only thing you can do is replace the switch.

I also have an old NEC digital stereo receiver that has the same switches.  They also failed in the same manner.

Ed

[Johncanfield]

I have two of them, one of them I tried to repair with new switches and things went horribly wrong  . I'll take a look at your video. They are really good counters, one of mine has an oven.

[TheDefpom]

This unit has a basic reference, not a very stable one (at least it takes a very long time to settle), I have purchased a couple of OCXO modules, I will need to make a pcb to put it on, but that's not a big deal.

Once I upgrade it so that its frequency is more accurate I will sell it, I purchased it to repair for a video for my channel.

[MarkL]

My 1992 front panel had two fractured PCB traces which rendered about half the keypad inoperable.  Seems there's all kinds of different fun lurking in these.

Mine's been running great for at least 10 years now.  They're nice units.

[bitseeker]

Nice job, Scott. IIRC that empty socket is where the ribbon cable from the GPIB board plugs into.

[on4top]

Just got a Racal Dana 2101 with OCXO and  A - B - C ports  ( c port up to 20 Ghz )

A & B port working fine .. C port doesn't trigger ..

Service manual for  1991-92 etc seem to be easy to find .. for 2101 still looking ..

http://www.sglabs.it/en/product.php?s=racal-dana-2101&id=1613

The C port has 3 seperate extra can's  ( 1 is sampler where N-connector goes to ) ( when removed/disconnected  . port A & B still work fine )