A while ago I made an eBay buy of an FE 5680A rubidium source made by FEI. This is supposed to be programmable for output in the range 1Hz to
20 MHz. I am wondering if anyone knows how to program this particular unit?
These were part of a Motorola SGLA4000B High Stability Ocillator used in cell sites. At first, I thought my unit was dead because I got no output when I fed it +15 V using the limited information and pinout on the FEI web pages. Eventually I figured out that this one needs both +15 V and
+5 V.
I have worked out that 2 of the pins connect to RS232 Tx and Rx on a MAX3232 inside the unit. I assumed it was going to program the same as a FE 5650A, as described here:
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So far, I get no reply to anything I have sent to the RS232 pins. Anyone happen to know more?