2 Freq. Counters measuring - GPSdo's

[bingo600]

This is a "fun" graph

I have just got a HP 53132A w. opt10 (Thnx Steve) , and decided to do some tests.

Red  : PM6680B (Tbolt 10Mhz ext clk) - Measuring the 10Mhz out (10811 int. OCXO) from the HP 53132A
Blue : HP 53132A (10811 OCXO int clk) - Measuring the 10Mhz out from my HP Z3801A

Both counters run frequency mode w. 1 Sec gate time.

No doubt the 10811 OCXO in the HP 53132A is a bit high , and needs a bit of adjusting.





No doubt the 10811 OCXO in the HP 53132A is a bit high , and needs a bit of adjusting.

Well i just got a 3GHz prescaler card for the 53132A , and have a "Quiet" 12dB 9m3 fan waiting also.
I'll adjust the OCXO when i do the 2 other mods.


Now i regret not having routed the 1PPS from the Tbolt to the outside.
I will have to do that , and start reading up on TI measuring on the 2 counters.

But couldn't i do TI measures , by feeding the Tbolt 10MHz to "Counter Ext Ref In" , and also to "Chan 1/Start" , and then Z3801A 10MHz to "Chan2/Stop"

I will prob try on all 3 counters : PM6680B , HP 53132A and HP 5370B.

/Bingo

[bingo600]

Ohh

My LED Magnifier lamp , creates spikes in the HP53132A readings when turned on/off.
Prob. a "Lousy psu inside".

Any "easy" hints to dampen the impact, preferably on the Led Lamp.

/Bingo

[bingo600]

Just had a quick glance @Service manual , and it seems that the "Real" Opt10 board has an onboard DAC.
And can be calibrated via the menus.

Is it possible to calibrate the TimeBase only ... wo. calibrating the interpolators  ? - "Read anything but the interpolators"
I don't have the equipment to do the "advanced" TI interpolator calibration.


/Bingo

[TheSteve]

Yes, you can calibrate the timebase only and nothing else - it is very easy to do and even gives the instructions on the VFD.