-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Daun Yeagley
Sent: Sunday, January 21, 2007 6:42 PM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] 10811 warmup (Jason Rabel)
Hi Jason
I might have something for you
To: [EMAIL PROTECTED]; 'Discussion of precise time and frequency
measurement'
Subject: Re: [time-nuts] 10811 warmup (Jason Rabel)
Made'm red just for ya in the updated 10811 manual
DO NOT OPERATE THE OVEN CIRCUITS WHEN THE OVEN MASS IS OUTSIDE OF THE
OSCILLATOR
INSULATED HOUSING. DOING SO
: Sunday, January 21, 2007 1:04 AM
To: [EMAIL PROTECTED]; 'Discussion of precise time and frequency
measurement'
Subject: Re: [time-nuts] 10811 warmup (Jason Rabel)
Made'm red just for ya in the updated 10811 manual
DO NOT OPERATE THE OVEN CIRCUITS WHEN THE OVEN MASS IS OUTSIDE OF THE
OSCILLATOR
PROTECTED] On Behalf
Of Jason Rabel
Sent: Sunday, January 21, 2007 4:36 PM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] 10811 warmup (Jason Rabel)
Thanks Bruce,
I think we have gotten a little off-subject here... My issue is not with the
oven, but the oscillator
It's bizarre..
The oscillator is some kind of Colpitts but with coils
instead of capacitors in the feedback path.
(i don't call it a Hartley, bcause Hartley's use a
SINGLE tapped inductor.)
73 de Normand VE2UM
--- Dr Bruce Griffiths [EMAIL PROTECTED]
wrote:
Hal Murray wrote:
Is it okay to
Normand Martel wrote:
It's bizarre..
The oscillator is some kind of Colpitts but with coils
instead of capacitors in the feedback path.
(i don't call it a Hartley, bcause Hartley's use a
SINGLE tapped inductor.)
73 de Normand VE2UM
--- Dr Bruce Griffiths [EMAIL PROTECTED]
wrote:
Dr Bruce Griffiths wrote:
Some form of mode suppression is required in most precision overtone
oscillators.
Bruce
I forgot to mention that the 10811 operates on the 5th overtone,
and it is also necessary to prevent oscillation at other overtones.
The mode suppression design takes care of
and frequency measurement
Subject: Re: [time-nuts] 10811 warmup
The oscillator is derived from a conventional Colpitts
circuit, with a capacitor from base to emitter, a
capacitor from collector to emitter, and the crystal
(in parallel resonance mode acting as an inductor) from
the collector
DUH! You wrote it Rick! LOL!
http://www.hpl.hp.com/techreports/1999/HPL-1999-6.pdf
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Subject: Re: [time-nuts] 10811 warmup
On this unit, I suspect the oven was not at the correct operating
temperature. Thus, although it warmed up to some extent, it may
not have reached 80 degrees C. The real diagnostic would be to
slide it out of the case and look at the voltages on the thermistor
Jack Hudler wrote:
Could physical damage to the crystal account for this deviation?
Pretty unlikely. If you drop a crystal, it will just break and
not work. The only way it could go down 100 Hz is by mass loading.
I don't know how this could happen in a sealed unit.
Rick Karlquist N6RK
Okay, I finally got around to building a little interface for my HP 10811's
this afternoon. I'm using a 24V supply for the oven. I built the oven
monitor LED circuit like in the manual so I know when it is warmed up so I
don't have to always probe the pin. Finally I'm using a linear regulator to
Is it okay to power up the main assembly once it is removed from the
outer shell / insulation?
Lots of info here:
http://www.hparchive.com/Manuals/HP-10811AB-Manual.pdf
I think I saw a warning about that, but maybe it was something else.
--
These are my opinions, not necessarily my
Hal Murray wrote:
Is it okay to power up the main assembly once it is removed from the
outer shell / insulation?
Lots of info here:
http://www.hparchive.com/Manuals/HP-10811AB-Manual.pdf
I think I saw a warning about that, but maybe it was something else.
It is OK to power up
Is it okay to power up the main assembly once it is removed
from the outer shell / insulation?
The oscillator circuit, yes. The oven circuit, no.
Is there any way to test just the crystal can easily
(assuming it doesn't rattle)?
Yes, follow the instructions in manual section 8-95. You
Yep yep... Thanks to all who have replied... I just finished reading the
whole service section of the manual, so I think I'll just take it one step
at a time and see how it goes. I'm still hoping for a loose connection or
broken wire, who knows.
I must of read at least 15 times 'do not power up
Jason Rabel wrote:
I must of read at least 15 times 'do not power up the oven circuit' in the
documentation... lol.
I am trying to think of why they say this. I don't see why
you can't power the oven when it is disassembled. I can see
that it might not reach 80 degrees or might oscillate and
AM
To: Discussion of precise time and frequency measurement
Cc: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] 10811 warmup (Jason Rabel)
Jason Rabel wrote:
I must of read at least 15 times 'do not power up the oven circuit' in the
documentation... lol.
I am
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