To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] OCXO Adjustment Question
Well, I also had some bad magic happen.
Last night, I decided that I would shutdown my HP 8935 so that I could
move it back to its usual place. When I turned it on this a.m. it
wouldn't power
Of Frederick Bray
Sent: Sunday, May 19, 2013 12:11 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] OCXO Adjustment Question
Well, I also had some bad magic happen.
Last night, I decided that I would shutdown my HP 8935 so that I could
move it back to its usual
Thanks for the info. I had a general idea that it might be something
like this, but it's helpful to know what to look for. I won't have time
to dig into it until next weekend. Unfortunately, HP's documentation is
not generally available so it may take some exploring.
On 5/19/2013 4:02 PM,
Hi Fred,
It sounds like you are turning it too far and too fast and expecting too much
from it. In old items, like what you have, those adjustments are fairly coarse
and required a very slight touch, then a wait and see, then another very slight
touch, etc.,. It sounds like you are turning a
Fred wrote:
I tried making small incremental adjustments but after I am done,
the frequency drifts several Hz and then re-stabilizes at a new value.
That is to be expected. Adjusting an oscillator is an iterative
process. After a while, you should get a feel for how far it drifts
after
One further thought: You say it drifts several Hz -- that seems like
quite a lot, if you are making small adjustments. I'd expect perhaps
several tens of mHz at most, although if it was way off when you
started, Hz might be possible at the first iteration. I suspect you
have a mechanical
[mailto:time-nuts-boun...@febo.com] On
Behalf Of J. L. Trantham
Sent: Tuesday, May 07, 2013 11:52 PM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] OCXO Adjustment Question
Fred,
What I do is to apply the GPSDO to the trigger input of a scope and the
output of the OCXO
Hi
Full blown, troublesome OCXO set procedure:
1) Touch the adjustment gizmo with your tuning tool. Don't adjust it. Watch the
frequency, does it bounce? (change over several minutes). If so, your tuning
tool is cooling off the oven. Find a lower thermal conductivity tool.
2) Take a
-
From: Bill Riches bill.ric...@verizon.net
To: 'Discussion of precise time and frequency measurement'
time-nuts@febo.com
Sent: Wednesday, May 08, 2013 11:52 AM
Subject: Re: [time-nuts] OCXO Adjustment Question
This is the method I use for my 5110. There are two 10 mhz outputs on the
osc - you
A couple if items that may have already been mentioned:
1. You've probably already seen the effects of the capacity of your adjustment
tool on the oscillator frequency if you are adjusting a variable capacitor. It
sometimes becomes a tweak, remove tool, watch and tweak again issue. If you
Thanks for all the helpful suggestions and comments so far. I will
answer a few of the questions that have been raised.
The device definitely is an OCXO as it is in an oven and gets warm. It
is an Ovenaire 73-25.
As one person commented, there are two 10 MHz outputs on the device.
One point of clarification. In my last post I said:
So far, the range seems to be from around 9.75 to 10.25 and it
has been on for over 18 hours.
That is not how much it drifts, but rather the range over which the
frequency on the counter has varied as I have tried to touch up the
, just spend your time 'tweaking'.
Joe
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Frederick Bray
Sent: Wednesday, May 08, 2013 11:21 AM
To: time-nuts@febo.com
Subject: Re: [time-nuts] OCXO Adjustment Question
Thanks for all the helpful
...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Frederick Bray
Sent: Wednesday, May 08, 2013 11:44 AM
To: time-nuts@febo.com
Subject: Re: [time-nuts] OCXO Adjustment Question
One point of clarification. In my last post I said:
So far, the range seems to be from around 9.75 to 10.25
One of the things I hadn't adequately considered was how quickly / much
the oven cycling affects things. I wasn't really thinking about this
when tweaking the adjustment so I wasn't doing them at a consistent
point in the cycle.
Now, it looks like it may be cycling from a low of 10.01 to
Of Frederick Bray
Sent: Wednesday, May 08, 2013 2:00 PM
To: time-nuts@febo.com
Subject: Re: [time-nuts] OCXO Adjustment Question -- Oven Cycling
One of the things I hadn't adequately considered was how quickly / much
the oven cycling affects things. I wasn't really thinking about this
when tweaking
On 05/08/2013 10:50 PM, Bob Camp wrote:
Hi
If it's moving up and down from +1 to +17 Hz from 10 MHz relative to 10 MHz,
it's broke. Either the OCXO it's self is in trouble or the supply going into
it has an issue.
... or as a remotely an issue a weak connection creating too much serial
This might be slightly off-topic, but probably there is a time-nut who
knows the answer.
I am trying to adjust the 10 MHz OCXO in a Cushman 5110 service
monitor. I am using a frequency counter driven by a GPSDO. Perhaps
someone can educate me about a couple problems I am encountering.
I
: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Frederick Bray
Sent: Tuesday, May 07, 2013 9:25 PM
To: Discussion of precise time and frequency measurement
Subject: [time-nuts] OCXO Adjustment Question
This might be slightly off-topic, but probably there is a time-nut
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