comparison: content/hp5334a.rst
content/hp5334a.rst
- changeset 32
- 6ede33beeeed
- child 44
- 96b26fb52f0b
equal
deleted
inserted
replaced
| 31:db7bbef8e263 | 32:6ede33beeeed |
|---|---|
| 1 ================================================= | |
| 2 Quick overview of the HP5334A Universal Counter | |
| 3 ================================================= | |
| 4 | |
| 5 :author: David Douard | |
| 6 :date: 2016-03-12 | |
| 7 :Category: Electronics | |
| 8 :Tags: test equipment, 10MHz, Rubidium, hp5334a, counter | |
| 9 | |
| 10 | |
| 11 The HP5334A is a decent universal counter. It has a two 100MHz | |
| 12 channels. Some models come with an optional third channel (1.3GHz), an | |
| 13 optinal DVM, and an optional oven controlled | |
| 14 oscillator. Unfortunately, my meter has no option at all. | |
| 15 | |
| 16 .. image:: {filename}images/hp5334a/front.jpg | |
| 17 :alt: My HP5334A Universal Counter | |
| 18 | |
| 19 There is a nice quick instruction set printed on the top cover: | |
| 20 | |
| 21 .. image:: {filename}images/hp5334a/top.jpg | |
| 22 :alt: HP5334A Quick Instruction Set | |
| 23 | |
| 24 | |
| 25 On the rear panel are 2 BNC (ref in/out and gate), the power socket | |
| 26 and the GPIB connector. One thing is a bit annoying on this device, | |
| 27 it's the fact that there is only one BNC for both the external 10MHz | |
| 28 reference input and the internal 10MHz reference output, with a small | |
| 29 Ext/Int switch to select the mode. So I have to reach the rear of the | |
| 30 device to switch this later when I want to use my `Efratom 10MHz | |
| 31 reference standard`_ (since I don't intent to keep it running every | |
| 32 time I want to user the 5334). | |
| 33 | |
| 34 When removing the covers, one can see: | |
| 35 | |
| 36 .. image:: {filename}/images/hp5334a/pcb.jpg | |
| 37 :alt: The top view of the PCB. | |
| 38 | |
| 39 with a very nice star-shaped ground lattice. Among other interesting | |
| 40 things are these funny little variable caps: | |
| 41 | |
| 42 .. image:: {filename}/images/hp5334a/c89.jpg | |
| 43 :alt: C89, a nice little variable cap. | |
| 44 | |
| 45 And as one may expect in such a device, no fan. | |
| 46 | |
| 47 The bottom side of the PCB looks like: | |
| 48 | |
| 49 .. image:: {filename}/images/hp5334a/pcb_bottom.jpg | |
| 50 :alt: The bottom view of the PCB. | |
| 51 | |
| 52 Adjustment | |
| 53 ========== | |
| 54 | |
| 55 My 5334 does not have the high stability timebase option (Option 010), | |
| 56 so my counter's stability specs are: | |
| 57 | |
| 58 - aging rate < 0.3 ppm per month | |
| 59 - tempco < 5 ppm (0°c to 50°C) | |
| 60 - line voltage < 0.1 ppm for 10% change | |
| 61 | |
| 62 And it was not so out of specs: | |
| 63 | |
| 64 .. image:: {filename}/images/hp5334a/uncal.jpg | |
| 65 :alt: Measuring a 1kHz reference | |
| 66 | |
| 67 In this picture, the signal is a 1kHz sine wave generated by a | |
| 68 HP8904A_ using my `Efratom 10MHz reference standard`_ as 10MHz | |
| 69 reference, so it should be pretty close to a solid 1.000000kHz. The | |
| 70 gate time delay is the default 0.3s. | |
| 71 | |
| 72 On this device, the crital oscillator adjustement variable capacitor | |
| 73 is accessible directly from the rear panel. I guess that without the | |
| 74 high stability option, the 10MHz time base was not part of the | |
| 75 calibration process and had to be adjusted quite often. | |
| 76 | |
| 77 So I've used the rubidium reference standard to adjust the internal | |
| 78 10MHz oscillator and I have, for now, a mush better 10MHz internal | |
| 79 clock (here we measure directly the 10MHz signal, and the gate time | |
| 80 delay has been set to 1s, as described in the service manual when | |
| 81 adjusting the oscillator): | |
| 82 | |
| 83 .. image:: {filename}/images/hp5334a/cal.jpg | |
| 84 :alt: After adjustement against the rubidium reference standard. | |
| 85 | |
| 86 The adjustment capacitor is not fine enough to reach a spot 10MHz | |
| 87 value, the best I could achieve is a 0.2Hz away from the expected | |
| 88 value, which is quite excellent, actually. | |
| 89 | |
| 90 But let's see within the next few days if it drifts a lot or not (as I | |
| 91 am writing this, it has moved a tiny bit to 10.0000005 MHz... 0.5Hz | |
| 92 off, something like 0.05 ppm). | |
| 93 | |
| 94 | |
| 95 .. _`Efratom 10MHz reference standard`: {filename}/10MHz_ref.rst | |
| 96 .. _HP8904A: {filename}/hp8904a.rst |
