[time-nuts] HP 10811

[Richard (Rick) Karlquist]

On 2/11/2016 2:56 PM, ws at Yahoo via time-nuts wrote:
> Joe
>
> The inner oven voltage needs to be stable! To better than 0.1V.
> Unlike the single oven unit, the inner oven on the dual oven unit runs fine
> at 15 Volts. It draws a couple hundred ma after warm-up.
>

It's been a long time, but IIRC, it was common knowledge
within HP that the standard 10811 oven will run on 15 Volts,
but it just takes longer to warm up.  The most extreme
example was the 5334A, which had such a bogus power supply
design that the voltage sagged to +12V during warmup.
Now the oven won't work correctly on only 12V, but it
will work to the extent that it warms itself up.  Once
the current cuts back, the voltage goes back up to over
15V and it works fine.  When I started the 5334B project,
the power supply was the first thing to get redesigned.

Rick N6RK