HP 5316A Teardown and Frequency Standard

[Kjo]

I have assembled three different kits for this OCXO design which is compatible
with both the HP5315A and HP5316A.
Everything is through-hole and assembly can be completed in 15-20 minutes.
At this time I have the kits on my website @:

https://www.hollywoodcontrols.com/phpHP/HP004OK.php

Where you can get the kit with or without the MV85 oven oscillator
or just the single PCB.

If you prefer eBay you can get the same thing at:

https://www.ebay.com/itm/155741314023

But eBay takes about 25-30% of sellers price which includes listing price, shipping and sales tax.
So the prices are higher.

[AMR Labs]

Anybody know if the HP5316A/B uses reciprocal counting for the lower frequencies? so measurements are fast and accurate even in the low Hz range. If not, is there a similar HP model that does use reciprocal counting? Thank you.

[bdunham7]

Anybody know if the HP5316A/B uses reciprocal counting for the lower frequencies? so measurements are fast and accurate even in the low Hz range. If not, is there a similar HP model that does use reciprocal counting? Thank you.

Yes, it is a reciprocal counter and will give you an accurate reading in one gate cycle. 

[pqass]

Anybody know if the HP5316A/B uses reciprocal counting for the lower frequencies? so measurements are fast and accurate even in the low Hz range. If not, is there a similar HP model that does use reciprocal counting? Thank you.

According to 3-4 of the 5316A operating manual:  "To maximize resolution, the 5316A uses a reciprocal counting technique for frequencies below 10 MHz, automatically switching to conventional frequency counting for frequencies above 10 MHz."

[AMR Labs]

According to 3-4 of the 5316A operating manual:  "To maximize resolution, the 5316A uses a reciprocal counting technique for frequencies below 10 MHz, automatically switching to conventional frequency counting for frequencies above 10 MHz."

Thanks guys, then indeed I was looking at the correct model. Its a pain having to wait 10 seconds before getting a low Hz reading with my current counter, specially when trying to make fine adjustments to a 60Hz oscillator.

[hvontres]

A few things to keep in mind:
1) If you don't need GPIB, a 5315B will have the same features. In fact, the main microcontroller used is the same mask from part. The oscilator mod works on both.
2) The OXCO mod is well worth it if you can't find one with the factory option
3) If possible, I would look for a unit that has the third channel installed. That will allow you to go up to about 1.2 Ghz or so.

[AMR Labs]

A few things to keep in mind:
1) If you don't need GPIB, a 5315B will have the same features. In fact, the main microcontroller used is the same mask from part. The oscilator mod works on both.
2) The OXCO mod is well worth it if you can't find one with the factory option
3) If possible, I would look for a unit that has the third channel installed. That will allow you to go up to about 1.2 Ghz or so.

Yes, ideally looking for installed options 003 and 004, although I have other counter for higher frequencies so C-Channel would be nice to get but not indispensable. My main goal is having something that will count low Hz frequencies without the typical 10 second gate time. And that OCXO board shown earlier in this thread seems easy enough to build if missing.

5315 and 5316 model form factor is very similar to 3468 and 3478 DMMs. BTW still looking for a handle for my 3468A.

[bdunham7]

Thanks guys, then indeed I was looking at the correct model. Its a pain having to wait 10 seconds before getting a low Hz reading with my current counter, specially when trying to make fine adjustments to a 60Hz oscillator.

What is your current counter?  If it is not reciprocal, then even with a 10-second gate you will only have 1 decimal point, 60.0Hz?

[AMR Labs]

What is your current counter?  If it is not reciprocal, then even with a 10-second gate you will only have 1 decimal point, 60.0Hz?

Exactly, I just get one decimal. That is why I would like a reciprocal counter.
I still can get 5 decimal places like 60.00000Hz with the build-in CTT option of my 2465B, but for this application I would rather need a dedicated separate counter like the HP5315/16.
As a GP counter I use the Optoelectronics 8010a up to 1.1Ghz that came with the OCXO option. Also have an Audio Frequency Meter build into the COM-120B with the lowest range being 0-200Hz but it also defaults to only 60.0 with just one decimal as at the lower end is rather meant to mostly count low frequency signaling tones like CTCSS, so one decimal resolution is more than enough for its intended application.