I bought a FE-5650A rubidium standard reference from eBay in the hope I can readily use it:


Unfortunately this is far from "reasily useable".

First and foremost, there is no RF connector (SMA, BNC, ...). Where is the 10 MHz output? (I hope it doesn't come out via the pin header, as it would result in significant interference

Second, the attached picture says there is a 9 pin connector:

enter image description here

However, there is only a 2x10=20 pin connector on my device. How to connect a simple 15V benchtop supply to this?

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    $\begingroup$ hm, the depicted "option 58" outputs a pulse-per-second signal, not 10 MHz as the ebay seller claims. $\endgroup$ – Marcus Müller Jan 14 at 19:05
  • $\begingroup$ @MarcusMüller I think this is the solution (if you write an answer with this I can accept it). I wrote the seller and will be trying to return. $\endgroup$ – divB Jan 14 at 22:43

See http://www.leapsecond.com/museum/fei5650a/FE5650A-pin-out.gif for the pin out of option 58.

FE5650A pinout

http://www.leapsecond.com/museum/fei5650a/ supplies more detail.

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  • $\begingroup$ Thanks a lot, this is very useful! See the remark from Marcus Mueller: If you add that this device is actually NOT the frequency standard but only the 1pps option, I can also mark your answer as accept :) $\endgroup$ – divB Jan 15 at 2:35

The datasheet that I found online has a picture of what looks like an F-connector on the same side as the multi-pin connector. That's where your output should be.

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  • 1
    $\begingroup$ There isn't – look at the ebay photos! $\endgroup$ – Marcus Müller Jan 14 at 18:53
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    $\begingroup$ The datasheet shows a connector. If the one that the OP bought doesn't have one, then it's probably been modified. In his or her shoes, I'd try to return it to the stock configuration by adding a connector. That does leave the question of where it should connect internally, which may be difficult to determine, but the buyer accepted the challenge when the purchase was made. Caveat emptor. $\endgroup$ – rclocher3 Jan 14 at 19:35
  • $\begingroup$ The OP says that there is no RF connector of any type. $\endgroup$ – Mike Waters Jan 15 at 3:21

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