FS: [US] HP Agilent 5071A Cesium Primary Frequency Standard, with good CBT

[testpoint1]

HP Agilent 5071A Cesium Primary Frequency Standard, with a very health CBT tube, 39999 USD:
https://www.ebay.com/itm/186451617025

[colorburst]

Copied the eBay description here for posterity, seems like useful information:

hp 5071A cesium beam Primary Frequency Standard 5071A is the most famous Cesium standard, in excellent working condition (using standard CBT tube), E-mult voltage only 1510V, still in very young period, I beleive the unit stay in warehouse more than 20 years since A2 board broken (I fixed it now). please be aware the E-mult voltage is most important parameter to verify the Cesium Beam Tube's life. the maximum value is 2553V, if you found that is 2553V, that mean it is died or very soon be died. so, if you want to buy a used and good 5071A (LED green), please check the E-mult voltage, the value from 1100V to 2553V (actually is -1100 to -2553V), that is its life evaluation way;

and CBT value may reach 90% of the 5071A, if CBT is near to end of life, the price of 5071A should be quite cheap, you can check all the listing in Ebay for the 5071A as parts, can you find a health CBT? BTW, I can fix any problem of the 5071A easily except CBT tube.

contine working more than 1 week, no any alarm, the video is using the 5071A as reference, to test phase noise and frequency stability of symmetricom X72;

the internal battery is two lead battery (12V, 2.5AH), already took out since it was no voltage;

the log following from the 5071A:

Code: [Select]

scpi >

scpi > DIAG:LOG:PRINT?

Log status: 14  entries



Log 000 of MJD        0 00:02:33:  Lock completed

Log 001 of MJD        0 00:02:45:  Power source is BATT

Log 002 of MJD        0 00:04:51:  Power source is AC

Log 003 of MJD        0 01:23:48:  Power source is BATT

Log 004 of MJD        0 01:27:30:  Power source is AC

Log 005 of MJD        0 08:01:58:  Power source is BATT

Log 006 of MJD        0 00:03:18:  Lock completed

Log 007 of MJD        0 00:02:33:  Lock completed

Log 008 of MJD        2 12:28:23:  Power source is BATT

Log 009 of MJD        0 00:02:07:  Lock completed

Log 010 of MJD        0 01:47:31:  Power source is BATT

Log 011 of MJD        0 01:52:35:  Power source is AC

Log 012 of MJD        0 01:54:20:  Power source is BATT

Log 013 of MJD        0 01:56:30:  Power source is AC





scpi > SYST:PRINT?



MJD        0 06:38:04

CBT ID: 3124A00247(S)

Status summary: Operating normally

Power source: AC

Log status: 14  entries



Freq Offset:          0e-15  Osc. control:    -44.96 %

RF amplitude 1:    33.0 %    RF amplitude 2:    31.5 %

Zeeman Freq:      39949 Hz   C-field curr:    12.158 mA

E-multiplier:      1510 V    Signal Gain:       14.4 %



CBT Oven:           5.6 V    CBT Oven Err:      0.00 C

Osc. Oven:         -8.6 V    Ion Pump:           0.4 uA

HW Ionizer:         1.1 V    Mass spec:         10.9 V

SAW Tuning:         1.5 V    DRO Tuning:         5.7 V

87MHz PLL:          1.0 V    uP Clock PLL:       3.4 V

+12V supply:       12.4 V    -12V supply:      -12.4 V

+5V  supply:        5.4 V    Thermometer:       35.2 C






ship from MA to US 48 states in free.

[testpoint1]

I changed the price to 19999 since I need to move home soon.

[testpoint1]

I made two new battery for its standby mode:
https://www.ebay.com/itm/186536924596

you can swap the AC power within 1.5 hour.

for the HP 5071A, price drop to 12999 USD.