Recommend me an OCXO.

[Vgkid]

Ironically that Racal 9500 was the first Frequency counter I was looking at getting. Ordered one on Ebay, and got a message from the seller the next day, saying that his shop was broken into. So no 9500 for me, ended up getting a 5335A.  Now I'm contemplating getting a prologix gpib(used), already downloaded ezgpib/timeLab.
It has begun...

[Vgkid]

my stp2145A 's came today, along with a neat little gps board.

[Vgkid]

The board works, now to wait until summer to start the project.
currently running a non scientific test using the 3456A monitoring the stability of the EFC output voltage.
will update later:
temp span 22.5+/- 1.5C
low = 8.01727   Hi = 8.01734  mean = 8.01730  var = =.170525E-9
count = 6411 measurements, 100nplc, 6 digits

[bingo600]

It has begun...

Poor sod   
Being bitten by the time bug is EXPENSIVE

My infection started with "just wanting to cal" my old PM6674 counter.
Ended up with 3 x Tbolts , 5 x Rubidiums

You have been warned 

/Bingo

And now i've been bitten by the volt bug 

[feedback.loop]

You may want to check out this video: https://youtu.be/0UT6smae8M0
Two OCXOs are tested there:
1. Morion MV85a 5V sine wave
2. C-MAC 12V square wave

[Vgkid]

Thanks for the video. If you dont mind me asking, where are you from?
I think i might have most beat on number of ocxo's. 54

[Vgkid]

Measured the current draw at 21C for the stp2145A
init = 546mA, min = 147mA, avg = 178mA

[xrunner]

100 MHz OCXO - Valpey Fisher. Form Ebay for $40. Now I have a 10MHz and a 100 MHz. Must obtain more ...

[Vgkid]

I almost thought about picking up a 100MHZ ocxo. Currently logging the evc out on one of the 2145A's. Which is being fed by a rather precise(and stable) 10v source(as opposed to 12v). will update later.

[Hole]

I know its old, but just to add some details.

I got a racal 9500 series counter and here is what I found inside. Name seems to be M95OSEO or M950SE0.

Previouse owner marked "option 22a installed" in the manual, which says "Aging rate: < 3x10^-9/day, Temperatur stability: < 3x10^-97°C 0° C to +50° C, Voltage Stability: <2x10^-8 with 10% line V variation".

It looks like C5 had to suffer some abuse. Not sure what all the stuff does... Currently the counter is very very spot on.

[Vgkid]

C5 might be a decoupling capacitor.

[Hole]

Yes, all the lighter colored ones seem to be decoupling. And it totally looks like a later made hack.

Another mystery is channel C. It is available as option 41 (50 to 512 Mhz) and option 42 (50 to 1.25 GHz). I can't find out what is build in, I don't see any markers etc.

Perhaps I should draw a schematic...

[times passes...]

ocxo is a Frequency Std. 9442/5, 5 MHz fast warm up. And I assume that the pcb is some frequency doubler (OR + RC).