Do you have any strange/antique device to show-and-tell?

[opablo]

I saw really nice photos of strange or antique multimeters in the post Show 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...

[EEVblog]

I'm afraid I don't, sorry.
Dave.

[opablo]

I'm afraid I don't, sorry.
Dave.

[EEVblog]

Brain fart.
I though the OP was asking me directly, and that this was in the suggestions category. 

Dave.

[G7PSK]

!927 Megger insulation tester and 1937 frequency meter all my other meters are at least ten years younger than this.

[peter.mitchell]

Those frequency meters are awesome btw.

[opablo]

Can anybody briefly tell me how that frequency meter works ?

[peter.mitchell]

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.

[free_electron]

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.

[DenzilPenberthy]

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.

[SeanB]

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.

[SeanB]

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.

[G7PSK]

Can anybody briefly tell me how that frequency meter works ?

The 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. 

[MartinX]

PHILLIPS PM3230 - Dual trace - 10MHz - Circa 1971... those guys were more patient than I with the valves heating up...

That 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.

[jeroen74]

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 days 

I bought it from a then co-worker together two other Elektor pieces somewhere in the late '90s.

[jancumps]

I have read that article (over and over again). Had a subscription to Elektuur at the time.

[opablo]

That 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.

I 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; from Bull(The french company) when they closed their Argentina branch.

[Psi]

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 needle



And, speaking of meters, here is probably the smallest meter you've seen.

[david77]

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 days 

I bought it from a then co-worker together two other Elektor pieces somewhere in the late '90s.

I 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.

[jh15]

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

[SLJ]

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.htm

And here's a 1937 Supreme 2" Cathod-Ray oscilloscope.


More of my early Supreme Instruments collection here: http://www.supremeinstruments.org/

[ftransform]

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.

[Hypernova]

400A!? What was that thing used in?

[c4757p]

400A!? What was that thing used in?

Old-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...

[notsob]

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.