10Mhz frequency reference for R2001A

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greg_kulosa
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Joined: Mon Jun 18, 2012 2:17 pm

10Mhz frequency reference for R2001A

Post by greg_kulosa »

I got an R2001A/HS on eBay, and the only thing wrong with it is the 10Mhz frequency reference. If I connect an external reference to the BNC on the back, then everything works fine.

I wanted to "upgrade" it to a Rubidium reference, since there are a number of surplus ones available for pretty cheap, but I can't find one that fits into the small space available under the CRT tube.

So, now I am thinking about replacing the internal reference and using my Rubidium reference externally when I want the extra accuracy.

Is there a source for the High Stability reference? Would one for a 2001D model work in a 2001A machine, or were they very different?

Thanks for the help.
jry
Posts: 481
Joined: Fri Feb 06, 2004 3:14 pm

Re: 10Mhz frequency reference for R2001A

Post by jry »

I would attempt to repair what you have first. Even if the 10Mhz OCXO/TCXO is bad you can often unsolder and repair those.
If it is the OXCO/TCXO is the issue than the last time I looked it seemed there are a number available on Ebay.
You may be able to use a OXCO off of a D series but the supporting board is different since it uses a mechanical switch to enable the external reference
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fineshot1
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Re: 10Mhz frequency reference for R2001A

Post by fineshot1 »

I have seen sometimes small vectron 10mhz ocxo modules on ebay for not a lot of $.
I picked one up and they are incredibly stable and accurate. Stabilization time was
only about a minute.

You may possibly be able to fit one of them inside and adapt it to the 2001A if you remove the original.
fineshot1
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DJP126
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Re: 10Mhz frequency reference for R2001A

Post by DJP126 »

The ocillator used in the R2001 series is the same one for all generations.
Dave
greg_kulosa
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Re: 10Mhz frequency reference for R2001A

Post by greg_kulosa »

Folks, thanks for all the information. It turns out that the oscillator is fine, the issue is that the control board is not supplying 9volts to the oscillator. I clipped the lead from the board, and ran 9volts to it from an external variable power supply, and the monitor started working.

So, it looks like the voltage regulator transistor is bad on the board. Digikey stocks an MJE-700G that will hopefully work. Again, thanks for all the help.
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