[Boatanchors] [Fwd: HP8601A Sweep Generator]

[Arthur Shulman]

On reflection, I think this should go to the BA list, as I have been
told that this equipment is a favorite generator for maintaining Collins
receivers.

-------- Original Message --------
Subject: HP8601A Sweep Generator
Date: Mon, 21 Oct 2002 22:26:07 -0400
From: Arthur Shulman <dentist@nornet.on.ca>
To: "test-equipment@mailman.qth.net" <test-equipment@mailman.qth.net>

I have just taken delivery of a (like) new 8601A sweep generator that is
apparently in perfect condition except for one minor problem: low level
residual FM.

I am not at all sure that this is a defect or the normal operation of
this instrument, and I wonder of anyone familiar with the peculiarities
of the 8601A can advise.

When in the CW mode, 11mhz range at 2mhz, fm is evident on the carrier;
I would guess, from crude measurements, that the deviation is about
300hz at the frequency. Of course I expect this increases (?) on the
110mhz range.

Frequency of this modulation is 120 hz, showing a distorted sine wave.

+20, -6.3 vdc power supply lines are free of ripple, but the -75vdc line
shows 5 mv ripple at 120 hz.

My schematic shows this line bypassed to ground with a 10 ufd cap; an
additional 25ufd cap from line to ground made no difference in
modulation level.

My question is should I be concerned about this, or am I seeing normal
operation for this instrument? I haven't used it for a 'real' alignment,
and don't know if this is a real problem or not.

Arthur Shulman VE3ZV