I have been puzzled by a mistake which has been published recently on this
list and elsewhere as well. It concerns the operation of the HP 10811
double oven TCXO used in the HP Z3801 GPSDO.
It is claimed that the outer oven is only in use during start up or during
extremely low ambient temperature
Hi
Well, based on conversations with the people who designed the part,
the outer oven’s only function was to take care of a potential cold end
problem. At the time, the telecom guys were thinking of putting GPSDO’s
in systems with no heating on the enclosures. That idea died when they
ran into a
Then what was the purpose of the inner oven?
Tom Holmes, N8ZM
-Original Message-
From: time-nuts On Behalf Of Jarl Risum
Sent: Wednesday, April 08, 2020 3:53 PM
To: time-nuts@lists.febo.com
Subject: [time-nuts] The 10811 double oven mystery
I have been puzzled by a mistake which has
On 4/8/2020 12:53 PM, Jarl Risum wrote:
I have been puzzled by a mistake which has been published recently on this
list and elsewhere as well. It concerns the operation of the HP 10811
double oven TCXO used in the HP Z3801 GPSDO.
It is claimed that the outer oven is only in use during start u
On 4/8/2020 2:02 PM, Tom Holmes wrote:
Then what was the purpose of the inner oven?
Tom Holmes, N8ZM
-Original Message-
The inner oven has a thermal gain around
1,000. When my colleagues at HP proposed
to wrap a 2nd oven around it, I predicted
that the additional thermal gain due
kb...@n1k.org said:
> Well, based on conversations with the people who designed the part, the
> outer ovenâs only function was to take care of a potential cold end
> problem.
> At the time, the telecom guys were thinking of putting GPSDOâs in systems
> with no heating on the enclosures. Tha
Hi
Running a hard disk at -40 C is pretty much a no-go sort of thing. Even finding
CPU
or FPGA chips rated for operation down there is difficult / expensive. DRAM
chips with
the “right” timing … not so much. Bottom line - the heater / HVAC costs *way*
less than
designing all that stuff to wo
But cooling / heating systems designed to work over a Wide temperature range
(ie. Parts of Northern Canada where outside temperatures of perhaps -40C in
the winter and +35C in the summer are within the relm of possibility) can be
somewhat more expensive / complicated than systems designed for
Hi
It was one of those things that sounded like a great idea when they first
sketched
it up. Once they dug into the grubby details, it didn’t make as much sense.
This was
back in the early 90’s. The guts of a cell tower were quite a stretch to come
up with
back then, even at normal temperatures
On Donnerstag, 9. April 2020 03:58:11 CEST Hal Murray wrote:
> What's the problem with digital gear at cold temperatures? The only one I
> can think of is that electrolytic capacitors stop working when the
> electrolyte freezes.
The two most common problems are that gates switch too fast so timin
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