Identification of Old Electrical Stuff - ONE MORE NEW PIC easy one - Page 1
Forum section: electronics / repair

author: vidarr
author_rank: Frequent Contributor
timestamp: February 16, 2020, 05:38:33 pm
content: Hi Guys,Cleaning out my Father-in-Law's shop with my wife (he died a couple years ago). He was an engineer and played around with a lot of electrical/electronic stuff. I found a bunch of stuff that I don't know what it is and thought you guys might have fun figuring it out.I have no idea what the first and second things are.The third thing looks like some kind of homemade probe? But I don't know for what.The fourth thing is the world's first computer. Museum piece, or garbage?The last things I think I posted another one like it here a long time ago. Some kind of tuner? There a a lot of these. Not sure if I should put in the recycle bin.There is a lot more stuff I haven't taken pictures of yet. Many things in metal boxes/cases with no markings. I need to open them all to see the circuits. And piles of driver circuits to who knows what.Most of the stuff I know. Lots of radio equipment: CB, ham radio, antennas, (they build homemade antennas in Brazil to use USA military satellites, so all of that stuff). Also, tons of stereo and mono audio equipment. Most everything is pre-1980s, so it is kind of cool to look thru.Thanks

author: reeks
author_rank: Newbie
timestamp: February 16, 2020, 05:44:20 pm
content: Hello, The second one seems to be an old relay, the last one is a trimable capacitor likely used in old radio equipment.

author: grumpydoc
author_rank: Super Contributor
timestamp: February 16, 2020, 05:52:22 pm
content: Google/Wwikipedia suggest that the TK82-C is a Brazilian clone of the Sinclair ZX81

author: Gyro
author_rank: Super Contributor
timestamp: February 16, 2020, 05:59:33 pm
content: The first one is a film splicer (or possibly a mag tape one).The third on is a home-made logic probe.Interesting ZX81 clone.

author: Stray Electron
author_rank: Super Contributor
timestamp: February 16, 2020, 06:00:18 pm
content: NO idea on the first but it doesn't look like any electrical.the IC on the circuit board is a Quad 2 input NOR gate. It looks like it's rigged to be a ring counter and to blink the LEDs.the last one is a pair of variable air gap capacitors. Before the advent of solid state tuners, these were commonly used to tune LC circuits to tune radios.

author: vidarr
author_rank: Frequent Contributor
timestamp: February 16, 2020, 06:02:06 pm
content: Quote from: grumpydoc on February 16, 2020, 05:52:22 pmI see people sell them, but this one has a chipped corner and the electronics are probably broken and there are no other components that I can find. I wish I had someone to donate it to.Thanks!

author: SeanB
author_rank: Super Contributor
timestamp: February 16, 2020, 06:02:32 pm
content: No 1 film cutter, used to splice 8/16mm film for a home projector.No2 Siemens plug in industrial relay, probably around 24VSC coil.No3 home made CMOS logic probe, looks like it was made mid 1980's.No4 looks like a clone of the Sinclair ZX81.No5 left is a 3 stage variable capacitor, right is a single stage unit, both probably 30-500pF per section.

author: vidarr
author_rank: Frequent Contributor
timestamp: February 16, 2020, 06:04:28 pm
content: Thanks everyone!Those air gap tuning capacitors, are they worth more than scrap aluminum? Should I donate them somewhere?Thanks!

author: vidarr
author_rank: Frequent Contributor
timestamp: February 16, 2020, 06:12:21 pm
content: Quote from: SeanB on February 16, 2020, 06:02:32 pmHe used a clear plastic, tic-tac container as the container for the circuit. It is kind of cool.Those variable capacitors I don't know what to do with. There are so many of them. Maybe someone who is building a post apocalyptic 2-way radio can use them?Again, thanks everyone.

author: Gyro
author_rank: Super Contributor
timestamp: February 16, 2020, 06:48:33 pm
content: Quote from: vidarr on February 16, 2020, 06:12:21 pmAir spaced variable caps are quite expensive these days. Worst case, clean them up and sell on ebay. They can be used for antenna matching units etc. You could also use one to as the bottom range of a lab capacitance box, giving you the first 0 - 1 or 1.5nF.

author: vidarr
author_rank: Frequent Contributor
timestamp: February 16, 2020, 07:09:33 pm
content: Some new stuff I opened up. I kind of get what they are, but not exactly. The first one is a transformer, but also has a thrisistor on the back and some other circuit design I don't fully get.The second one looks like some kind of variable voltage supply. edit: I don't understand what the switch for "5V" and "Normal" is all about. Actually, I don't get what this thing is for at all.The first two go together.the second two go together.Thanks!

author: grumpydoc
author_rank: Super Contributor
timestamp: February 16, 2020, 09:54:21 pm
content: Quote from: vidarr on February 16, 2020, 07:09:33 pmTIP32A is not a thyristor - just an NPN power transistor - so N1 1 is a little, 9v (ish) home made linear supply.

author: Stray Electron
author_rank: Super Contributor
timestamp: February 17, 2020, 12:30:17 am
content: first picture: an AC transformer, bridge rectifiers on the circuit card along with filter caps. So a basic unregulated DC power supply.Second picture: Ok I guess that this is the rear of the same item. That's voltage output regulator transistor.Last picture; the 7812 is a fixed 12 VDC voltage regulator. the 741 IC is a variable voltage regulator with the output voltage set by external resistors. So it's a power supply regulator board.Third picture: I'm guessing this is the complete unit containing the board in picture #4. One of the probably controls the output of the 741 shown in #4. The other control probably controls the output of the 3rd IC but I can't see what it is. So I'm going to say that this is another power supply' probably with a fixed 12 VDC output and 2 adjustable DC outputs. However I don't see a transformer so it must use an external one.

author: Stray Electron
author_rank: Super Contributor
timestamp: February 17, 2020, 12:47:54 am
content: Quote from: grumpydoc on February 16, 2020, 09:54:21 pmAgree. The transformer is marked 9-0-9 so it's probably 18 VAC output with a center tap. So depending on how the rectifiers are connected it could be up to about 25 VDC output. Most likely, it's considerably less, 12 to 15 VDC at a guess.

author: fzabkar
author_rank: Super Contributor
timestamp: February 17, 2020, 02:42:36 am
content: Quote from: Stray Electron on February 17, 2020, 12:30:17 amCould the 7812 be providing the power for the two 8-pin ICs rather than providing an output from the unit?The 741 is a jelly bean op amp, or are you suggesting that it is in some way involved in power supply generation?

author: coromonadalix
author_rank: Super Contributor
timestamp: February 17, 2020, 03:30:21 am
content: Quote from: SeanB on February 16, 2020, 06:02:32 pm+1 for all he wrote, the capacitor is trash, too rusted

author: coromonadalix
author_rank: Super Contributor
timestamp: February 17, 2020, 03:32:49 am
content: An lm 741 could be used as an comparator or a reference voltage in a power supply design, lots of pictures on the web ..

author: PaulAm
author_rank: Frequent Contributor
timestamp: February 17, 2020, 03:04:12 pm
content: If you have any radio amateurs around, somebody might be interested in the variable caps; they still find some use. Maybe somebody interested in antique radio repair.The rust is no big deal, they can be cleaned up with a dunk in citric acid.

author: vidarr
author_rank: Frequent Contributor
timestamp: February 18, 2020, 04:53:51 pm
content: One more pic. I looked this up, but cannot find it. "LIGA" means "ON" in Portuguese. I have no idea what kind of switch this is.All the other stuff, thanks everyone!Thanks!

author: schmitt trigger
author_rank: Super Contributor
timestamp: February 18, 2020, 05:16:09 pm
content: Quote from: vidarr on February 16, 2020, 06:12:21 pmDon't throw them away!! As other posters have mentioned, they are no longer produced, but vintage radio collectors may have use for them.Clean them and sell them on Ebay

author: vidarr
author_rank: Frequent Contributor
timestamp: February 18, 2020, 05:57:46 pm
content: Yes, Thank You. I already put ALL of them aside. Thanks to everyone here, I am getting a MUCH BETTER Understanding of all this stuff I am sorting thru. My expertise is computers software/hardware. This other stuff is still very new to me, but I am figuring it out bit by bit. I actually really want to learn, so I am putting effort into this. I am pretty sure I am going to go headfirst into this radio electronics. Especially, learning if it is possible to create something that can survive Solar Flares and the Earth's Magnetic Pole Reversal (happening right now).I was hoping to find an oscilloscope in all this stuff, but no such luck. I did find an Atari and games. I also found a working, pre-9/11 computer, complete with monitor and all the peripherals (& Windows 98). That was an EXCELLENT find. Any computer hardware pre-9/11 is maybe not expensive monetarily, but it is worth a lot as a tool as it was pre-NSA. It's been awhile since I've been in touch with the p-9/11 groups, but there are ongoing projects and apps being developed in "underground" communities -- mostly on IRC.That last switch I posted I cannot figure it out. It has two on positions and one is called "Save" and the other is called "Load".

author: SeanB
author_rank: Super Contributor
timestamp: February 18, 2020, 07:18:08 pm
content: Just a regular double pole double throw switch in a repurposed box, probably to control something like a light, from the use of what used to be called lamp cord, these days no longer legal in most countries for mains use, because it is single insulated, so now commonly sold as speaker cord.

author: vidarr
author_rank: Frequent Contributor
timestamp: February 19, 2020, 12:32:02 am
content: This is Brazil. I have seen coat hangers and twist ties used as wire.OK, that is just a regular switch. It was in a cardboard box with more complicated stuff, so I wasn't sure what it was attached to previously. I don't play around with mains power yet, so I prefer to just ask before plugging things in. Thanks.

author: thinkfat
author_rank: Unknown
timestamp: February 19, 2020, 08:55:10 am
content: Quote from: schmitt trigger on February 18, 2020, 05:16:09 pmNot only vintage radio collectors, but also HAM radio operators. The capacitors have large enough airgap one could use them as tuning capacitors for a nice RF tube amplifier, or in a magnetic loop antenna.They're getting kind of rare items, too. If you clean them up, you can probably get a nice sum on ebay. More likely if you can measure their capacity range and add that info to the ebay listing.

author: vidarr
author_rank: Frequent Contributor
timestamp: February 19, 2020, 01:37:30 pm
content: Quote from: thinkfat on February 19, 2020, 08:55:10 amThis is what her dad was using them for. They are all different, so I think he collected them from various sources, but the ultimate use in his case was this ham radio hobby. He has enough stuff to set up a small town with radios.

author: schmitt trigger
author_rank: Super Contributor
timestamp: February 19, 2020, 04:01:21 pm
content: Remember the old adage: One man's trash, is another man's treasure.