Hickok 3410 Microvolt Multimeter - Page 1
Forum section: electronics / testgear

author: radhaz
author_rank: Regular Contributor
timestamp: August 28, 2016, 07:38:42 pm
content: This is an early '70s 5 digit DMM. Observations about it's design and construction are welcome.P8270398byryuuoh, on FlickrP8270397byryuuoh, on FlickrP8270396byryuuoh, on FlickrP8270395byryuuoh, on FlickrP8270394byryuuoh, on FlickrP8270393byryuuoh, on FlickrP8270392byryuuoh, on FlickrP8270391byryuuoh, on FlickrP8270389byryuuoh, on FlickrP8270388byryuuoh, on FlickrP8270387byryuuoh, on FlickrP8270386byryuuoh, on FlickrP8270384byryuuoh, on FlickrP8270383byryuuoh, on FlickrP8270382byryuuoh, on FlickrP8270380byryuuoh, on FlickrP8270378byryuuoh, on Flickr

author: Rbastler
author_rank: Frequent Contributor
timestamp: August 28, 2016, 07:44:04 pm
content: This is really awesomeAnd it has NixiesDoes it work and what is the reference ?

author: radhaz
author_rank: Regular Contributor
timestamp: August 28, 2016, 08:14:14 pm
content: It works. It appears to be out on AC volts and AC/DC current. On DC voltage, it matches my in-cal Iwatsu 7602. I think that aluminum block with what looks like metal can diodes might be the reference.

author: radhaz
author_rank: Regular Contributor
timestamp: August 29, 2016, 04:24:59 am
content: For camera nuts, these pics were taken with an Olympus EM-1 with 60mm Macro and 12-40 Pro zoom, all hand held.

author: Muxr
author_rank: Super Contributor
timestamp: August 29, 2016, 04:28:47 am
content: Quote from: radhaz on August 29, 2016, 04:24:59 amThat's a great system. I am still using my e-m5, love the 60mm macro. Beats the pants of my full frame 105mm Nikkor Macro lens.

author: Vgkid
author_rank: Super Contributor
timestamp: August 29, 2016, 06:29:01 am
content: Thanks for the teardown. That AL block is very interesting, the datecodes are all over the place. From 74-78

author: Cubdriver
author_rank: Unknown
timestamp: August 29, 2016, 08:14:58 am
content: Cool old meter and nice photos, especially impressive as you're hand holding. What are you using as a light source?-Pat

author: Gyro
author_rank: Super Contributor
timestamp: August 29, 2016, 10:28:01 am
content: Quote from: radhaz on August 28, 2016, 08:14:14 pmThat aluminium block looks a bit more like an optical chopper to me. Two LEDs and 2 phototransistors as part of a chopper stabilised amplifier.

author: SeanB
author_rank: Super Contributor
timestamp: August 29, 2016, 05:16:26 pm
content: Look at all those vanished companies that made the parts in there, almost all of those companies either no longer exist, or are part of another through mergers and such.

author: radhaz
author_rank: Regular Contributor
timestamp: August 29, 2016, 11:38:15 pm
content: Lamps are a combo halogen desk lamp with a Chinese LED ring light attached and an Ikea goose neck table lamp.Quote from: Cubdriver on August 29, 2016, 08:14:58 am

author: Cubdriver
author_rank: Unknown
timestamp: August 29, 2016, 11:44:50 pm
content: Nicely done. I normally use ambient lighting, a tripod, cable release and long exposures with the lens stopped down to about f/11 for decent DOF.-Pat

author: radhaz
author_rank: Regular Contributor
timestamp: August 30, 2016, 12:11:06 am
content: Hopefully the manual I ordered for the 3400 series meters will reveal the secrets.Quote from: Gyro on August 29, 2016, 10:28:01 am

author: radhaz
author_rank: Regular Contributor
timestamp: September 03, 2016, 11:44:17 pm
content: Got the manual yesterday. The aluminum block is indeed a chopper amplifier using CL9D6CS photo cells and OSL6-3 solid state lamps. The voltage reference is a 1N827A temperature compensated zener diode and LM201A opamp.

author: Gyro
author_rank: Super Contributor
timestamp: September 04, 2016, 03:01:10 pm
content: Ah, that's good - they used solid state rather than the flickery neons that HP used in their early opto choppers. I went over those photos with a fine tooth comb looking for a 1N82x, I still can't see it!

author: radhaz
author_rank: Regular Contributor
timestamp: September 04, 2016, 04:31:35 pm
content: The 1N827 is near the three grey trim pots. Picture P8270386 has the best view if it.

author: Gyro
author_rank: Super Contributor
timestamp: September 04, 2016, 07:17:41 pm
content: Aha, yes, got it. The white body threw me.

author: radhaz
author_rank: Regular Contributor
timestamp: September 29, 2017, 02:39:23 am
content: Correction on the display technology, this is a VFD display multimeter. Sorry nixie fans.

author: Whiteygabe
author_rank: Newbie
timestamp: June 14, 2018, 06:27:22 am
content: Hi everyone,i need the squematic or the service manualThanks to allGabe