[time-nuts] Re: HP 5065A, no 2nd harmonic.

[Jared Cabot]

Hi,

Ok, I managed to get a moment to do a few tests. I'll try to answer the questions so far, sorry if I miss something out.

For test equipment, I have the following gear of possible use:
- HP 5335A 200MHz Universal Counter with 1.3GHz option
- Leo Bodnar GPS Reference
- HP 34461A Multimeter, just calibrated.
- Tek TDS748C 1GHz Scope
- Multiple HP E361xA Power supplies
- 3325A Function Gen (All options)
- Many other bits of gear too, including a billion TM500 modules and mainframes etc.

On the 5065A front, I have replaced the resistors in the RVFR with Mil-spec Vishay RN55, RN60 and RN65 series parts, cleaned the glass elements and added a 100 deg.C thermostat to prevent over temperature events.
I have replaced all the wet tantalum capacitors in the entire unit with United Chemicon KYB 220uF, 63V capacitors (10,000 hour rated), bypassed with C0G/NP0 0.1uF MLCC ceramic caps, there was no PCB damage, but two tant caps had just started leaking, luckily not reaching the PCB's.
I added heat sinks to the two diodes on the A2 board and replaced the RIFA mains filter cap too. The 3 big mains filter capacitors tested well within spec, with leakage down around 10uA.

- On A8 Pin9, I get 137KHz, 174mV P-P

- A7 TP2 shows me random low amplitude noise

- A3 TP2 I see 5.38VDC

My serial number is 2432A01344 and I have the 10811-60109 OCXO (and no options fitted, so the chassis is clean of battery corrosion).


Thanks all for the help!
Jared
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