changeset
[hp5334a] new blog post about the HP5334A universal counter
Sat, 12 Mar 2016 01:36:48 +0100
- author
- David Douard <david.douard@logilab.fr>
- date
- Sat, 12 Mar 2016 01:36:48 +0100
- changeset 32
- 6ede33beeeed
- parent 31
- db7bbef8e263
- child 34
- 871fcc94f63e
[hp5334a] new blog post about the HP5334A universal counter
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/content/hp5334a.rst Sat Mar 12 01:36:48 2016 +0100 @@ -0,0 +1,96 @@ +================================================= + Quick overview of the HP5334A Universal Counter +================================================= + +:author: David Douard +:date: 2016-03-12 +:Category: Electronics +:Tags: test equipment, 10MHz, Rubidium, hp5334a, counter + + +The HP5334A is a decent universal counter. It has a two 100MHz +channels. Some models come with an optional third channel (1.3GHz), an +optinal DVM, and an optional oven controlled +oscillator. Unfortunately, my meter has no option at all. + +.. image:: {filename}images/hp5334a/front.jpg + :alt: My HP5334A Universal Counter + +There is a nice quick instruction set printed on the top cover: + +.. image:: {filename}images/hp5334a/top.jpg + :alt: HP5334A Quick Instruction Set + + +On the rear panel are 2 BNC (ref in/out and gate), the power socket +and the GPIB connector. One thing is a bit annoying on this device, +it's the fact that there is only one BNC for both the external 10MHz +reference input and the internal 10MHz reference output, with a small +Ext/Int switch to select the mode. So I have to reach the rear of the +device to switch this later when I want to use my `Efratom 10MHz +reference standard`_ (since I don't intent to keep it running every +time I want to user the 5334). + +When removing the covers, one can see: + +.. image:: {filename}/images/hp5334a/pcb.jpg + :alt: The top view of the PCB. + +with a very nice star-shaped ground lattice. Among other interesting +things are these funny little variable caps: + +.. image:: {filename}/images/hp5334a/c89.jpg + :alt: C89, a nice little variable cap. + +And as one may expect in such a device, no fan. + +The bottom side of the PCB looks like: + +.. image:: {filename}/images/hp5334a/pcb_bottom.jpg + :alt: The bottom view of the PCB. + +Adjustment +========== + +My 5334 does not have the high stability timebase option (Option 010), +so my counter's stability specs are: + +- aging rate < 0.3 ppm per month +- tempco < 5 ppm (0°c to 50°C) +- line voltage < 0.1 ppm for 10% change + +And it was not so out of specs: + +.. image:: {filename}/images/hp5334a/uncal.jpg + :alt: Measuring a 1kHz reference + +In this picture, the signal is a 1kHz sine wave generated by a +HP8904A_ using my `Efratom 10MHz reference standard`_ as 10MHz +reference, so it should be pretty close to a solid 1.000000kHz. The +gate time delay is the default 0.3s. + +On this device, the crital oscillator adjustement variable capacitor +is accessible directly from the rear panel. I guess that without the +high stability option, the 10MHz time base was not part of the +calibration process and had to be adjusted quite often. + +So I've used the rubidium reference standard to adjust the internal +10MHz oscillator and I have, for now, a mush better 10MHz internal +clock (here we measure directly the 10MHz signal, and the gate time +delay has been set to 1s, as described in the service manual when +adjusting the oscillator): + +.. image:: {filename}/images/hp5334a/cal.jpg + :alt: After adjustement against the rubidium reference standard. + +The adjustment capacitor is not fine enough to reach a spot 10MHz +value, the best I could achieve is a 0.2Hz away from the expected +value, which is quite excellent, actually. + +But let's see within the next few days if it drifts a lot or not (as I +am writing this, it has moved a tiny bit to 10.0000005 MHz... 0.5Hz +off, something like 0.05 ppm). + + +.. _`Efratom 10MHz reference standard`: {filename}/10MHz_ref.rst +.. _HP8904A: {filename}/hp8904a.rst
