[time-nuts] time-nuts Digest, Vol 77, Issue 4
ed_palmer at sasktel.net
Thu Dec 2 22:03:29 EST 2010
Have you checked the Z3801A info at this web site?
There are two versions of the schematic for the outer oven controller in
the Z3801 and Z3801A directories.
> Thanks to everyone for the pointers on getting my Z3801A/58503A
> working correctly. The pointer to the realhamradio.com really helped.
> I was looking for a schematic but the info on the realhamradio pages
> with pin outs and voltages was almost as good. I have finally decided
> that everything is working except the outer oven. There is no 14
> volts on the heater and no current is being drawn. An curious thing
> is that there are 2 DC to DC converters the main power converter is 24
> volts in and +12, -12, and 5 volts out and the input and output
> voltage is plainly marked on the side of the converter. The power
> supply supplied with the unit is 24 volts DC and the that converter is
> working fine. The second DC to DC converter is labeled UMR-5/4000-D48
> which according to the data sheets that I found is a 48 volt DC in and
> a 5 volt DC at 4 amps out unit. I dont understand why the 2 DC to DC
> converters would have a different input voltage with only the 1 power
> supply If anyone has any thoughts about this I would like to hear
> about them. Again my symptoms are that the unit seems to work but it
> is moving all over the place and moves in and out of spec which then
> takes it out of lock until it comes back into spec. I have sent the
> vendor a request but he is in Hong Kong and I havent heard back from
> him yet.
> Thanks, Jerry W5RCQ
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