But never right after you did the work. You have something called confirmation bias that that point, that means that you just put it there so it must be right and you’re not going to catch mistakes. Take some time away from the unit, maybe even the next day. You want to kind of forget what you just did.
Here’s the chassis, completed so far:
It’s still messy, but less messy than it was, and all of the parts are of known values.
Soldering
Soldering a chassis like this is always an adventure…I do each part in sections, so multiple components might get mounted before I solder things. Sometimes, I don’t solder things right away because I’m thinking that terminal may need something from a later section…regardless, sometimes things do not get soldered. There were a couple here:
Misplaced parts
There was one part I put in the wrong spot. The 180kΩ resistor that’s behind the capacitor in the foreground attaches to the lower terminal of the potentiometer in the background. That should have went to the top terminal. This was an easy fix, unsolder, trim the lead, and re-solder.
Missing parts
Here’s the jack on the back of the unit.
You can see there are two wires on the terminal. There’s also supposed to be a capacitor on that terminal to ground, and that part was laying right behind the unit in the tray I used to hold components. Here it is:
I was going to take it back to a terminal near the AC input, but eh. I took a terminal strip, made it into a 1 lug unit, hit it with 180W of iron and made that my new tie point. It’s a bit messy, but that solder isn’t going anywhere.
Checkout is complete. Everything is now where it should be going, and is soldered properly. Time to move on to the power-up.
Now that most of the top of the chassis is out of the way (yah right, I forgot some stuff and had to correct some wiring errors from the previous owner…) it’s time to do the bottom of the chassis.
There’s not much to say about this, so here are the rebuild images in no particular order save I tried to follow before with after in a particular section of the unit.
That’s pretty much everything except for the power cord. That comes at the very end, SICo just laid the cord over the chassis and through a tiny hole. There’s not enough room to actually pull the cord’s head through, so the back and power cord become one assembly. I’ll use a death cheater to bring it up after checks.
This thing had a rough life. It doesn’t really work right now save that it lights up and makes glow. Did it ever really work? Well…since I just wrote that, I think you can probably guess what I mean.
I can’t say I’ve seen a device that has corroded wire like this one does. Not all of them, just some.
It’s hard to see, but it’s speckled with green. I checked wires as I went, some needed replaced, some were replaced just because they were in bad shape otherwise.
The eye tube socket assembly.
Everything here was attached decently, but stuff just looked bad, and these wires were corroded.
Some new resistors and new wire, and it looks better. Still needs a bit of dressing, but that comes last.
The original builder put the eye tube at a weird slant. While the bracket itself can be moved on a slide, doing so puts the bolt for the bracket up against a terminal strip underneath because it was mounted opposite of how it should have been. That was corrected by just using a longer screw and some nuts as spacers. It’s not like this thing is going anywhere, so mechanical stresses aren’t a concern.
That’s all for the eye tube.
The grid cap for the 12C8.
This is the “signal tracer” portion of the unit, and it uses a WWII surplus tube, the VT-153/12C8. This tube was designed for radio service, and exposes one of it’s grids on the plate cap. That’s where audio is fed in for amplification. There are two parts, a resistor to ground that provides bias for the grid and a blocking capacitor for the audio so you don’t get DC in your device that’s under test.
That was easy enough to re-do.
Fairly standard work, there’s really nothing of note. It’s time to move on to the main body of the unit, and all of it’s “none of this matches anything you wrote down!” mess.
It’s been a while since I’ve done an eBay junk post, so it’s high time. The amount of AI slop has toned itself down a little bit, the wild descriptions of a few years ago have settled into a generic “A valuable and quality device” for most things. No, your hobbyist signal generator from 1963 isn’t widely used in industry.
There are other things on eBay that are quite amusing, however. One of those are these listings for a Delco Vibrator. No, that’s not a toy you have to go to those shops downtown in back alleys for, it’s an electro-mechanical part that was used in automotive radios when tubes were still king. It’s a relay that turns itself off, so it just sits there and vibrates at whatever speed it can, turning power on and off. It’s a mechanical pulse generator, and the pulses it generated were fed to a step-up transformer in order to make B+ for the tubes. There are modern solid-state equivalents if you want to rebuild an old car radio, but sometimes you want to open a can and stuff it so it looks like the OEM part.
So why post these? They’re amusingly bad - and in some cases probably an outright lie. They’re all Delco 1220155 Vibrators, and a few minutes online would tell you that. Names and prices have been removed to protect the guilty!
Part #1
This one purports to be a “Delco Radio Speaker Capacitor???” Not sure what a Capacitor??? is, but here’s one if you need it.
According to the seller, it’s a double-DIN radio as well. It’s from a working radio to boot.
Part #2
This one is also a capacitor, and the seller has tested it and found that it works. I’m confused as to how this happened, but apparently - it did. Is the seller just writing things there to fill space? Even Mister Owl doesn’t know the answer to that question. I mean…how does it work?
But you get some dust from their warehouse!
Part #3
This is probably the best one. It is from a listing that purports to be an auto parts reseller, and that the unit was left-over from a recent automotive restore. It, like the first one, is a “Speaker Capacitor???” Here’s an idea - if you’re selling auto parts and restoring cars, wouldn’t it be in your best interests to actually, oh, I don’t know, know what you’re selling?
While I could see where an inexperienced seller would make a mistake - these do look like capacitor cans - all you need to do it spend a bit of time online to find out exactly what this is.
Here’s an odd little device from a different age…this is a Jackson Model 710 Selenium Rectifier Tester. Manufactured by the Jackson Equipment Company of Dayton, Ohio, this is a single-purpose instrument in an attractive case. It was purchased at the Columbus Hamfest for $1.00.
There’s not a whole lot inside of it:
It even has it’s own little selenium stick rectifier at the top.
The business end is the massive multi-tap transformer inside the thing. This is what’s giving it weight.
It also has this cutely named “sele-rater” attached to one of the crumbling leads. I assume this is so you can determine (by physical size) what kind of rectifier you have in your device.
So, does it work? Here’s a selenium rectifier removed from the recent PACO G-30 rebuild. I know it’s still a good device, as it was pulled from a working unit.
Hooking it up and trying every combination of switches I can, I get no deflection on the meter. Ok, so what’s on the outputs of the device?
There’s pretty much nothing on the output, whereas there should be 130V under test. That tells me the selenium stick is probably bad. No surprise.
What’s going to happen to this? Well, it goes back together for now. It’s not a terribly high priority for me as it’s more of a “that’s cool” device. If I can find an appropriate rectifier at a show, I’ll drag it back out and fix it just to make it work. Otherwise, it’s an interesting display piece, and nothing more.
A month or so ago, I made a post about this device, the Superior Instruments Co Model 76 Bridge and Signal Tracer. The unit combines a single tube headphone amplifier for tracing with a bare-bones CR bridge for capacitor testing. You can find that post here: https://wereboar.com … cent-acquisitions-1/ if you’d like to read it.
There’s a lot going on inside of this device. Much of what’s going on inside of this device is of the “What?” variety as the schematic and device itself do not match very well, if at all. The basic components are there, but the actual values and some of what’s there isn’t.
Here’s the device schematic, courtesy of the BAMA archive:
That big motor starter capacitor with the 0.2μF wax-paper across it? On the schematic but listed as 0.02μF . Those two metal cans with no labels in the middle? Not on the schematic…what even are they? They look like capacitors but one measured nothing, the other measured 17μF with a capacitor analyzer. I don’t know that this was available as a kit, so either the OEM just stuck stuff in as needed to solve problems, or someone added these later. I’d go for the “added later” due to the multiple types of sleeving and the fact I’ve seen another one of these that didn’t have those parts.
But there are other things going on in here.
Those are the parts connecting the grid input of the VT153/12C8 tube to the input jack. The schematic states those two parts should be 0.02μF and 1.2MΩ, but instead they are 0.015μF and 820kΩ. Many of the 0.02μF parts in this device are actually 0.015μF ceramics.
Here’s the eye tube socket. Those resistors are also supposed to be 1.2MΩ but instead are 820kΩ. Like the capacitors in the previous image, many of the 1.2MΩ resistors specified are actually 820kΩ.
It’s obvious this device was built from surplus WWII components. The USN tubes, the RNx resistors, and the oddball parts are all surplus, so it’s no surprise that things don’t match here. However - it’s going to take some doing to rework this item as I can’t simply order things based on the schematic.
The device is working, so there is that. I’m going to work with it a little and try to produce a corrected schematic before proceeding. Stay tuned!
This is another one of the plastic blue boxes that were recently presented in this series, and the last one I have. There were two other devices in this series - a signal tracer which goes for a lot of money when you see them, and a VOM, which I’ve never seen. This particular device is the Heathkit IG-5280 RF Signal Generator.
This device is the spiritual successor to the signal generators of yore, the ones that put out the terrible partial sine wave with 1kHz modulation. This one offers 310kHz to 110MHz (on banana jacks no less!) with 1Khz of AM modulation possible. Pretty standard stuff…here’s the front panel:
I’m not going to bother with the rest of the box, you’ve seen those before and there’s nothing different on the other two. The inside is more or less just like the others as well.
I’m pretty sure there should have been a shield on this thing. It would make much more sense to have a shield here than on the audio unit - I can even see where screws were once upon a time. Look to the right, and that hole in the chassis plate is quite mangled. This is pretty much the equivalent of the flyback cage being open on a television, there’s probably something wrong here. The stickers on the top claims that it works. We’ll see…
The first thing that’s wrong is the power switch on the back. You can run this device on batteries, just like the others. The switch itself is rather flaky, and I had to set it in the middle and wiggle it to get it to work.
The audio output is a little squished, but operational. It’s 1.04kHz, not too bad.
The RF side is a different story. I can get a little bit out, and it doesn’t really change with the selector switch. The only thing I could get that was big enough for the scope to grab was on the highest scale, and that’s not much.
The only thing I could really get was that little sinewave and some modulated garbage.
I don’t have any need for this, or desire to troubleshoot it, so into the pile it goes.
This is going into the donate pile for the Early Television Museum auction. If you want it, it should be there, assuming I can get hold of them. Otherwise, it goes to some other donation channel.
It’s been a while since I’ve zipped up all the files in the document library, so it’s high time I do it again.
If you’d like a copy of everything I’ve collected for projects here, you can grab a copy of it from dropbox: https://www.dropbox. … ro3&st=djfaezpv&dl=0. The file is about 410MB, and is all of the files in a big .zip for easy extraction.
About a year ago, I had a small Waterman “pocket” scope on the bench. It needed some tubes, and had a bad power switch. In an effort to clean up the pile ‘o stuff waiting for bench time - here it is.
First thing I wanted to do was verify that the switch was indeed open, and it was:
By the condition of the unit, it was used quite a bit. Maybe one of the conditions that cause this device to be retired was that open switch. It was easy enough to fix, just a jumper across the terminals. Before attempting to plug it in, I verified that it had a fuse in it, and it was good.
There aren’t any shorts, I can see the transformer load on the cord. Plug it in! I can see tubes lit.
But, there’s nothing on the screen. I mess with the controls for a while and let it set. Nothing. Upon powering down and opening, I notice I can’t detect any heat on the neck of the CRT. Well…it may be open or have some other fault. That’s a show stopper here, and I remove my new tubes for later use.
This guy goes into the donation pile. Perhaps someone can make use of the parts.
This will be near to the last post of the year here on projects, and it’s something to browse while you’re waiting for the new year holiday to start. I found out earlier this year that you can reference galleries from different points within this blogging system, and thought it would be cool to have a year-end page with all of the stuff I saw at hamfests. So…here it is! The only ones that won’t be presented in that manner is the SCARF show in May and the Central PA hamfest - both of those because there were very few pictures. They’ll be links instead.
Without further ado, here is the stuff I saw this year at hamfests:
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The Sunday Creek ARF Hamfest, Shade Ohio.
A bunch of old-school test equipment.
That 1970s blue.
Still a lot of AM CB stuff.
A big, old, Heathkit power supply.
How big can you make a 5W CB?
I didn't buy a voltmeter this time!
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The Cuyahoga Falls ARC Hamfest, Cuyahoga Falls Ohio.
A nice AOR scanner with a serial control port.
A table full of audio related stuff.
BetaMax anyone?
A giant broadcast tube.
A small capacitor checker. This went home with me.
Some cool 1970s cases. I took a woodgrain special home.
Someone had a collection of early music video.
A lot of radios and tubes.
The club has a table of cheap stuff.
A coffin set. These have become cheap.
The inside of the coffin set.
Another coffin set.
Another coffin set. Would have got this if I had room.
I bet this thing can't hear WLW next to the tower.
A giant-size signal generator.
Some radios and one of those monitor scopes.
Self explanatory.
Some old Heath stuff. Some of it's not all that useful these days.
Another small Heath scope. Took this one home, it's in great shape.
Dad's homebrew projects.
Knobs. Need I say more?
I wonder who Lafayette was channeling here?
The last Heathkit of it's type.
Who didn't have one of these?
A stack of old meters.
An old mill controller.
How many of these were made?
A nice National radio.
Pulse generators.
Various rackmount equipment.
Surprise, radios!
Even more radios.
You guessed it, radios!
You'd think this was a radio show.
An “Electric Eye” science kit.
A nice old Solar cap checker with a meter instead of an eye.
I couldn't pass this up for $5.
I see you hiding in there.
A lot of different equipment.
Just some stuff. There was a calibrator here I took with me.
I wanted the triple stack, but we couldn't come to a bargain.
A television test jig and degaussing coil.
Some oddball one-off set made in the 1970s in the USA.
I love that they used a lot of color on these.
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The TUSCO Hamfest, New Philadelphia Ohio.
Some interesting equipment. Radio gear?
Lots of vidicon tubes. Lots and lots and lots!
The early 80s still live among us.
A dual band (lol!) Lafayette Radio.
I bet you never thought you'd see more radios.
AM/FM/8-Track with a cool honeycomb face.
Radio Shack ghosts haunt us.
A couple of old Tek (tube-type) scopes. Ok price.
A mini scope. That seems high priced.
Just stuff from the CFARC guys. I took the decade box.
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The Athens County ARA Hamfest, Athens Ohio.
CD-R…once a miracle, now just junque.
The camera doesn't do the chrome justice.
An interesting passthrough counter.
A desoldering iron from the tube socket era.
An all-in-one RF test station.
Some older test gear including a cap checker in the box.
An HP 200 series generator and an old tape player.
A “Portable” multimeter.
Once of those tube unit power supplies.
An old Sony reel-to-reel tape player.
A couple of scopes. Interesting, but not needed.
An interesting Sencore tube tester.
Radios and an overpriced PACO tube tester.
A bad shot of some old gear. Would have taken the rightmost one if it had been in better shape.
One of Trio's active panel meters.
One of Heathkit's interesting lunchbox tube testers.
Some radio tuning gear.
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The Dayton Hamvention, Xenia Ohio.
Friday:
I used to work for this toxic company.
Some big rackmount amps.
Somoe old Motorola comm analyzers.
A cool looking antenna controller.
A stack of audio gear.
A cool old blue B&H oscilloscope.
Lots of parts.
Stuff is just laid out on whatever.
It's chrome plated!
Lots of walkies.
A table full of consumer era radios.
One of those high-precision Regency counters.
Someone bought a box of CRTs and related materials.
A nice Heathkit decade box. Took this home.
A dirty Hallicrafters.
Not going to break this one.
Hard to believe it's only 1.7GB.
A giant dummy load. Dummy not included.
A nice Eico harmonic distortion analyzer. Went home as a project piece.
The accompanying Eico RF generator.
An Eico scope. Tempting, but I have too many scopes.
