HP 5386A frequency counter teardown - Page 1
Forum section: electronics / testgear

author: remageFrs
author_rank: Unknown
timestamp: March 14, 2016, 12:44:13 am
content: Hi!First post here, so I thought it'd be a good idea to take some inside photos of an HP 5386A frequency counter I scored recently on eBay.Also, I'm curious if anyone here has a similar counter with the "Option 004" OCXO timebase?Higher resolution images are here:HP 5386AMost of the ICs/caps have a late-'87 datecode, the TCXO has '8802' stamped on its side (but I'm not 100% sure that's a datecode), so I think it's an early '88 unit. Despite the age, the whole instrument looks really nice and clean.I didn't have the confidence to open up the RF shield on the 3 GHz frontend, sorry... :)Edit: Found theservice manualon Keysight's homepage.It mentions on page 2-4 that the standard oscillator can be replaced by the "Option 004" OCXO. The HP number is 0960-0636, I couldn't find any further info about it. Does anyone have an idea if a modern ovenized oscillator can be installed there?

author: deepskyridge
author_rank: Regular Contributor
timestamp: March 17, 2016, 11:26:18 pm
content: I have one just like it except mine has the OPT-004 installed. Nice counter, mine works fine.Gary

author: picburner
author_rank: Frequent Contributor
timestamp: March 18, 2016, 04:58:54 am
content: Nice instruments.A guy in Poland has made an option 004 clone and sell it on ebay.

author: remageFrs
author_rank: Unknown
timestamp: March 28, 2016, 07:32:35 pm
content: Found a NOS oven oscillator for the counter!

author: corn11
author_rank: Regular Contributor
timestamp: January 16, 2017, 05:57:11 pm
content: Quote from: remageFrs on March 28, 2016, 07:32:35 pmI have a 5385a on which I also want to install the option.May I ask where you've managed to get the original OCXO ?I've wrote some obsolete part suppliers but none of them has responded so far

author: corn11
author_rank: Regular Contributor
timestamp: January 24, 2017, 07:10:19 pm
content: I think I've found the OEM of the OCXO: Isotemp Research Inc. .They (presumably) sell the matching OCXO on eBay:eBay auction: #171831243622The given datasheet values correspond to the ones in the datasheet of the 5384A/85A/86A also the pinout and the shape, which aren't really common match.It would be a really strange coincidence if this isn't the OEM partI've recently ordered one and it should arrive this week.

author: calin
author_rank: Regular Contributor
timestamp: January 24, 2017, 08:20:06 pm
content: I have one too, no OCXO .. got it for 20$.. With the spare money I got an UBLOX and a Morion OCXO and a couple of chips and I am almost done getting a half a$$, good enough for my needs GPSDO.One thing that wold be a nice hack will be to add a backlight to the lcd.

author: mmagin
author_rank: Frequent Contributor
timestamp: January 24, 2017, 08:31:14 pm
content: I have the 1 GHz version of this (without OCXO) and I previously had the 225 MHz version (with OCXO). Nice little counters, though in both situations I used the 10MHz reference from my GPSDO instead. Interesting that HP put a third party OCXO in these instead of the 10811 -- presumably it was a lot cheaper.

author: corn11
author_rank: Regular Contributor
timestamp: January 24, 2017, 09:09:24 pm
content: Building a GPSDO is also on my list. I've already bought a Navman-GPS-module and a Trimble OCXO but had no time to get the thing together.So for now hopefully the OCXO option will do the businessyeah, a backlight hack would be really nice indeedI belief someone on the forum has already done this with a 3478A DMM.

author: Miti
author_rank: Super Contributor
timestamp: December 14, 2018, 03:05:40 pm
content: Quote from: corn11 on January 24, 2017, 09:09:24 pmhttps://www.eevblog.com/forum/testgear/hp3478a-backlight-my-version/msg1507039/#msg1507039

author: 0culus
author_rank: Super Contributor
timestamp: December 15, 2018, 06:30:03 am
content: Really nice and clean too! Good catch!I have a 5335A with the OXCO option (and I think pretty much every other option as well; even the DC voltmeter option) that sits on top of my 5350B microwave counter, and provides the timebase for it. I recently also replaced my shitty Chinese DDS with a 3325B from the same seller I got the counters from, which also has an OCXO, but it doesn't have an internal connection to it, so I have a jumper.

author: Jwalling
author_rank: Unknown
timestamp: December 15, 2018, 12:29:18 pm
content: Seeing as how this is a teardown thread, here's some pictures of the 3GHz prescaler.

author: rhb
author_rank: Super Contributor
timestamp: December 16, 2018, 12:08:06 am
content: Curiously, all my HP gear has the OXCO option except my Keysight 33622A. But I plan to connect everything to a GPSDO, so I don't think it matters much. Even without the OXCO the 33622A is very stable. But I haven't put together a test and verification plan for my bench yet.

author: Radiorandy
author_rank: Newbie
timestamp: February 28, 2019, 08:07:21 am
content: I've been trying to find the guy in Poland that has the Option 4 clone OXCO. Doesn't show up on Ebay. Anyone have a link or contact info?ThanksRandy

author: wkb
author_rank: Super Contributor
timestamp: April 26, 2023, 07:36:53 am
content: Quote from: Jwalling on December 15, 2018, 12:29:18 pmPage 63 shows a picture of one of the GaAs chips used on the hybrid.http://roryvantuyl.com/PDFs/The%20Early%20Days%20of%20GaAs%20ICs.pdfWilko