Do you have any strange/antique device to show-and-tell? - Page 1
Forum section: electronics / general

author: opablo
author_rank: Regular Contributor
timestamp: December 13, 2012, 05:17:55 am
content: I saw really nice photos of strange or antique multimeters in the postShow your Multimeter!Maybe we can extend that idea to any kind of strange/antique/exotic tool or device that you have around and want to share ?I present you... my only scope:I'm not old... I'm 29yo... It's just that I don't have money for a better one.I actually use this for my amateur projects and it works like a charm.PHILLIPS PM3230 - Dual trace - 10MHz - Circa 1971... those guys were more patient than I with the valves heating up...

author: EEVblog
author_rank: Unknown
timestamp: December 13, 2012, 05:24:53 am
content: I'm afraid I don't, sorry.Dave.

author: opablo
author_rank: Regular Contributor
timestamp: December 13, 2012, 05:28:23 am
content: Quote from: EEVblog on December 13, 2012, 05:24:53 am

author: EEVblog
author_rank: Unknown
timestamp: December 13, 2012, 09:41:42 am
content: Brain fart.I though the OP was asking me directly, and that this was in the suggestions category.Dave.

author: G7PSK
author_rank: Super Contributor
timestamp: December 13, 2012, 11:43:08 am
content: !927 Megger insulation tester and 1937 frequency meter all my other meters are at least ten years younger than this.

author: peter.mitchell
author_rank: Super Contributor
timestamp: December 13, 2012, 02:25:43 pm
content: Those frequency meters are awesome btw.

author: opablo
author_rank: Regular Contributor
timestamp: December 13, 2012, 03:10:24 pm
content: Can anybody briefly tell me how that frequency meter works ?

author: peter.mitchell
author_rank: Super Contributor
timestamp: December 13, 2012, 03:24:53 pm
content: I think they use 2 electromagnets placed side by side, with a row of metal tabs below them, then they use constructive and destructive interference in the field to vibrate certain tabs along the bar, the tabs along the bar represent the frequencies.

author: free_electron
author_rank: Super Contributor
timestamp: December 13, 2012, 03:33:22 pm
content: They send the current through an electromagnet. Each of these tabs has a different lentgh. They behave like a tuning fork. The one that is 'tuned' to 50hz will vibrate the most if 50hz is applied. So it will wiggle the most. You just look for the tab that is shaking up and down the hardest . Since the tip of the tab is painted white you perceive this as a white line. The tallest line is the tab vibrating the most. Simple mechanism.As far as oldest equipment.. My oldest stuff is about 15 years old... Sorry.

author: DenzilPenberthy
author_rank: Frequent Contributor
timestamp: December 13, 2012, 05:48:12 pm
content: Someone brought this into my workshop a little while ago asking if I knew what it was and did I want it. Haven't powered it up yet but it is a mercury relay. Looks like you energise the coil, the plunger moves down and displaces the pool of mercury which moves up to the contact on the right.Does anyone know anything about these? What is the advantage of using mercury rather than normal contacts? No contact bounce presumably?I work in a university physics department so there is tonnes of old stuff like this everywhere, I'll see what else I can find.

author: SeanB
author_rank: Super Contributor
timestamp: December 13, 2012, 05:53:00 pm
content: You have a coil wound so that the pole pieces are bottom and top of the display. The display is a spring steel strip that has slots cut to various depths through the sheet, so that at the right they are short and at the left they are long. Thus they act like a series of springs with changing resonance frequencies as you go along the strip. When you apply powewr all want to vibrate, but only those whose resonant frequency matches the incoming frequency show a build up of oscillation and show as a vertical bar on the front, the others barely moving.

author: SeanB
author_rank: Super Contributor
timestamp: December 13, 2012, 05:56:14 pm
content: The mercury relay is used as it has low contact bounce and more importantly a fixed contact resistance, while it is capable of operating in explosive environments and has a very long life. Only drawback is that it is direction sensitive ( use up only) and quite expensive, along with it containing a moderately toxic heavy metal.

author: G7PSK
author_rank: Super Contributor
timestamp: December 13, 2012, 06:26:22 pm
content: Quote from: opablo on December 13, 2012, 03:10:24 pmThe tuned reeds have a weighted end and are made to vibrate by an electromagnet, The one that is in resonance with the field vibrates the greatest amount. The meter is set for 25HZ with that reed painted red.

author: MartinX
author_rank: Regular Contributor
timestamp: December 13, 2012, 07:43:30 pm
content: Quote from: opablo on December 13, 2012, 05:17:55 amThat oscilloscope is a bit unusual because it is a true dual beam oscilloscope hence the separate intensity and focus knobs for each channel. Unfortunately it does not have dual time base, but dual beam was a necessity back then if you had the need to compare two signals in real time.I have an old Philips GM5601 bought as surplus from the Swedish air force, in perfect condition probably never used before I bought it in 1986, it has a sticker on the back saying the warranty expires in February 1964. Sadly I had to throw away the rubber viewing funnel that came with it, you could put it on the CRT bezel to block out ambient light, sorry I don´t know the English word for it. The rubber had totally disintegrated in the late nineties.

author: jeroen74
author_rank: Frequent Contributor
timestamp: December 13, 2012, 08:29:13 pm
content: I have this Elektor microprocessor controlled frequency counter:I always wanted one since I read the magazine article back in 1985 and I think it was quite some advanced piece of equipment for those daysI bought it from a then co-worker together two other Elektor pieces somewhere in the late '90s.

author: jancumps
author_rank: Unknown
timestamp: December 13, 2012, 09:24:46 pm
content: I have read that article (over and over again). Had a subscription to Elektuur at the time.

author: opablo
author_rank: Regular Contributor
timestamp: December 13, 2012, 10:33:20 pm
content: Quote from: MartinX on December 13, 2012, 07:43:30 pmI will try to post another photo of my oscilloscope showing how big it is, compared to my notebook which is on the side. And how the "visor hood" looks like (I just invented that name)And another photo showing the drawer that is beneath the device that you can slide and remove one specific board. It's components are super old and the pcb traces appear to be handwritten and curvy... really nice.I would like for you to tell me what makes that board so important to make it accessible for servicing (maybe a calibration board?)Anyway... I promise that you will like the pcb traces on that one.As yours, this one was obtained by my rip father in a similar way; fromBull(The french company) when they closed their Argentina branch.

author: Psi
author_rank: Super Contributor
timestamp: December 13, 2012, 10:48:35 pm
content: Here's a really old magnetic DC current sensor.You put the wire into the guide at the back and the magnetic field from the current in the wire moves the needleAnd, speaking of meters, here is probably the smallest meter you've seen.

author: david77
author_rank: Frequent Contributor
timestamp: December 13, 2012, 11:37:35 pm
content: Quote from: jeroen74 on December 13, 2012, 08:29:13 pmI have one too. Mine's not in the Elektor design case, though. I got it out of the estate of an electronics engineer together with some other things including all Elektor mags from 1978 to 89.That magazine was really quite good back then and that counter was rather advanced for a diy project.

author: jh15
author_rank: Frequent Contributor
timestamp: December 14, 2012, 04:21:02 am
content: I have a Hickok clone of a Tektronix 545 I am about to part out. I'll post a pix in a bit...And you think patent trolling is recent?http://federal-circuits.vlex.com/vid/tektronix-hickok-instrument-jetronic-lavoie-38402330

author: SLJ
author_rank: Frequent Contributor
timestamp: December 14, 2012, 05:14:59 am
content: I have hundreds of examples from the 1920s, 30s, and 40s so I'll just post a couple of interesting ones with links to some of the rest.I think the oldest pieces of test equipment I have are these DC polarity Indicators from around 1903-1910.They show polarity in a DC circuit using a liquid in a glass tube that when DC current is passed through it, the liquid in the negative end turns red. It has a patent date stamped on it of Oct. 25, 1905. The earliest ad I have found for it was published in 1903. It was available in two models, a model 3220 for testing the polarity of low voltage DC and battery charging circuits and a model 3221 for testing 50-600 volt DC circuits. They use a liquid filled glass tube that is enclosed in a hard rubber type case with a connector on each end. Electrodes inside the glass tube attach to the connectors. The metal sleeve can be rotated to cover the glass windows when carried in your pocket. More vintage test equipment:http://www.stevenjohnson.com/testers-misc.htmAnd here's a 1937 Supreme 2" Cathod-Ray oscilloscope.More of my early Supreme Instruments collection here:http://www.supremeinstruments.org/

author: ftransform
author_rank: Frequent Contributor
timestamp: December 14, 2012, 11:09:11 am
content: Wow that polarity indicator seems like a really interesting piece of equipment. I wonder how difficult it is to make your own using a piece of clear tubing.I wonder how large a current it needs.Awesome find.

author: Hypernova
author_rank: Unknown
timestamp: December 14, 2012, 01:04:29 pm
content: Quote from: Psi on December 13, 2012, 10:48:35 pm400A!? What was that thing used in?

author: c4757p
author_rank: Super Contributor
timestamp: December 14, 2012, 01:48:10 pm
content: Quote from: Hypernova on December 14, 2012, 01:04:29 pmOld-timey stuff? Seems like just about everything used ridiculous currents and voltages back then... I see lots of old ammeters that read into triple digit amperes and wonder where the hell the µA measurements are...

author: notsob
author_rank: Frequent Contributor
timestamp: December 14, 2012, 02:01:55 pm
content: They were used for measuring start current on tractors, the size of the U shaped shoe on the back fits over the cable from the 12V battery to the back of the starter motor, they easily draw over 200 amp on start.

author: G7PSK
author_rank: Super Contributor
timestamp: December 14, 2012, 03:07:29 pm
content: Quote from: Hypernova on December 14, 2012, 01:04:29 pmI have a Lucas one of those Has two guides on the back one right on the meter and the other stood off about 25mm for higher currents, It was given to me by a plant fitter that worked for Wimpy's plant.

author: BravoV
author_rank: Super Contributor
timestamp: December 14, 2012, 03:27:15 pm
content: Vintage 15 turns 10K potentiometer, source ->A Fat Ass Vintage PotentiometerSize comparison to a soda can.

author: SeanB
author_rank: Super Contributor
timestamp: December 14, 2012, 04:00:19 pm
content: I worked a little on ground support equipment for aircraft. DC generator was rated to deliver 8kA for 1 minute as a starter. When I used it to jump start an ambulance there to collect a casevac the needles did not even move off the zero stop, though the lights on the ambulance went from dim to very bright when the contactor was engaged.

author: TerraHertz
author_rank: Super Contributor
timestamp: December 15, 2012, 06:28:38 am
content: A few of my bits of 'precious old junk':http://everist.org/tales/20121215_relics.htm

author: SeanB
author_rank: Super Contributor
timestamp: December 15, 2012, 07:21:34 am
content: You need to fix the picture links, they are broken...........

author: TerraHertz
author_rank: Super Contributor
timestamp: December 15, 2012, 07:28:44 am
content: Force a reload, the first copy I uploaded was a draft, and the links had an upper/lower case error. Fixed it moments later, I guess your timing was unlucky.

author: SeanB
author_rank: Super Contributor
timestamp: December 15, 2012, 07:43:47 am
content: Your links have \ instead of / in them. IE probably converts, but other browsers do not

author: TerraHertz
author_rank: Super Contributor
timestamp: December 15, 2012, 08:14:03 am
content: Oh gosh, that's embarrassing. Actually ALL the html in that folder had the same problem, due to me just copy-n-pasting a source template. Despite that I do know better. Just wasn't paying attention. All fixed now.Also, Opera converts, which is why it worked for me.

author: peter.mitchell
author_rank: Super Contributor
timestamp: December 15, 2012, 08:19:53 am
content: Quote from: SeanB on December 15, 2012, 07:21:34 amworks for me :S

author: T4P
author_rank: Super Contributor
timestamp: December 15, 2012, 08:38:23 am
content: Chrome and chromium based browsers auto converts