[time-nuts] 5370A/B Problems

xaos xaos at darksmile.net
Mon Sep 12 21:58:41 EDT 2005

Hello everyone,

This is my first posting to Time-Nuts so please bear
with me if I don't have the proper etiquette.

I guessed that many members here have the
HP5370A(B) counters.

I have 1 5370A and 2 5370B.

For some weird set of circumstances,
all three units failed withing 1 week.

The problem in the 5370A turned out to be
contact problems in the Power up relay.
After much cleaning I was able to get the
unit back up and running.

The 5370B's were much worse off.
It seems that they both suffer from failures
in the U24,25,26 chips on the Arming board.

Unfortunately, the two units are not identical
and I cannot cannibalize one to fix the other.

What I can do is use some chips from the 5370A
to fix the older model 5370B.

So(at last) my question is:

Should I do this?

I am very hesitant about breaking a perfectly
good 5370A which has seen much good service.

BTW, I can't find replacement chips anywhere
on the net.

Many thanks,

George Hrysanthopoulos, N2FGX

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