[time-nuts] HP 5061A problem

Morris Odell vilgotch at bigpond.net.au
Mon Aug 18 07:16:29 EDT 2008

Hi all,

My 5061A has failed and I've isolated the problem to a faulty A18, the +3500 
volt ion pump power supply.

The existing one has almost certainly has had the internal 200M resistor go 
open as the output voltage is about 5 kV and it does not decay quickly when 
the power is off.  The output voltage to the current sensing circuit is 0.

I have a replacement which I suspect is faulty - when energised from a +18 
volt source it only produces 2 kV which decays quickly and the sensor output 
is +20 when the thing is unloaded. That 200M resistor may have gone low! Is 
this one worth installing ie: will +2 kV pump enough ions?

So I'm looking for a replacement or advice from anyone who may have 
attempted to repair one.

If anyone has a parts donor of course I'd be happy to pay appropriately 
including shipping down here to Australia.


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