[time-nuts] Z3805A cooling requirements?
lists at rtty.us
Thu Dec 20 21:09:09 UTC 2012
You can telnet into the 5125 to get longer data plots. It's a royal pain to
do. You then need to run the data through something like TimeLab or Stable32
to turn it into ADEV.
I think you will find that *if* the temperature in the draft is stable, the
ADEV hit will settle out. It'll take longer than the simple return to
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Said Jackson
Sent: Thursday, December 20, 2012 11:47 AM
To: Discussion of precise time and frequency measurement
Cc: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Z3805A cooling requirements?
The ADEV plot was done after the unit had fully settled to it's new location
in front of the 53132A fan.
The Tsc5125A instrument has a limit of 9 minutes to plot the frequency drift
for some reason, so I can only show you the last 9 minutes.
The transient due to the new temperature was long gone when I started this
~20 min ADEV plot.
Sent from my iPad
On Dec 20, 2012, at 4:36, Bob Camp <lists at rtty.us> wrote:
> Did I miss part of the data?
> The plot I got shows about 9 minutes. Temperature step stress takes a
*long* time to settle out.
> On Dec 19, 2012, at 9:56 PM, SAIDJACK at aol.com wrote:
>> Not sure about that, if you look at the frequency plot after ~20 minutes
>> moving air the frequency was still extremely close to 10.000000MHz.. to
>> within <1E-011 of 10MHz. This is a free-running 10811.
>> Compare that to the plot of the OCXO I had sent out some hours ago when
>> was running stable inside the foil - there was almost no average
>> change between the two tests.
>> If the heaters had an issue keeping average crystal temperature stable,
>> then the frequency would have changed from the first plot to the last
>> would think. In my opinion the airflow is just adding a huge bunch of
>> control loop noise to the output stability, or there are components on
>> PCB which are very sensitive to the airlfow. Consider that this unit and
>> it's PCB was designed to live inside the 53132A (very close to the fan)
>> I am now using as an air source. One thing this tells me: the fan in the
>> counter could be disabled and it would improve the units stability, if
>> keeps an eye on internal counter temperature.
>> In a message dated 12/19/2012 18:42:08 Pacific Standard Time,
>> actast at hotmail.com writes:
>> I think the data shows that the heaters were losing ground, which would
>> explain the steadily falling temp of the SC cut quartz.
>> Thomas Knox
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