EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: tkamiya on July 11, 2020, 05:39:15 pm
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I have an HP53132A with option 01 board, 53132-60004. The OCXO is Isotemp OCX033-46. On the PCB sub assembly, there is a jumper W1 right below J1. Is it supposed to be shorted or not shorted? Please note, this is not the same board that was used in more recent 53132A which can take any OCXO.
Symptom is, it can not be auto calibrated. Before I started tweaking OCXO, I'd like to make sure it is optioned correctly.
Thank you.
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Issue is resolved. OCXO has drifted out of range. Put it back around 10MHz and autocal works.
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Maybe the OCXO is bad with too much drift, noise and jitter, look at both.
You need to watch the OCXO for a while to determine its quality.
I had a similar issue and replaced the OCXO.
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That's very possible. Thanks for your reply.
I bought this counter used about 2 years ago, and this is the first time I calibrate the internal oscillator. I've always used it with lab standard 10MHz so it's hard to tell if it drifted or it was misaligned at some point.
I'll keep my eyes on it.
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THIS is this dis-concerting!
I actually have two HP53132A
Unit #1 had a "good" OCXO option 01
Unit #2 I just repaired.
I also have an OCXO standard that's just an ordinary OCXO 8663-01.
Using house standard (GPSDO) as reference and extending gate time to 1 second so I see all 12 digits, Unit #1 is showing last 3 digit off and 2 digit fluctuating, and Unit #2 is showing 4 digits off and 3 digit fluctuating. This is right after successful calibration.
It would be interesting to replace the internal ocxo with 8663, do something like Mr. Sweeney did....
Another option is do away with high spec option entirely and make a new box with Rubidium standard. They just don't drift!
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I just recently bought a 53131A and upgraded it with a MV89A OCXO. PCB designed by this kind fellow: www.circuitvalley.com (http://www.circuitvalley.com). Gerber files here: https://github.com/circuitvalley/agilent_53131A_53132A_options/tree/master/Time_Base_Oven (https://github.com/circuitvalley/agilent_53131A_53132A_options/tree/master/Time_Base_Oven).
The parts are pretty recent, just the 5V reference was a bit hard to obtain. Found it at RS eventually.
Pretty happy with the result, though the 53131A is of course not in need of such a beast of an OCXO. But it's nice that it doesn't drift a lot.
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Thank you!