- 2024
- Dec
- 27
An Olson TE-189 C-R Analyzer - Rebuild, part 4 - What actually was replaced?
When I started this project, it was going to be a replace some caps and move on. Well…the unit was such a basket case that it needed a lot more love. So what was replaced?
Almost all of the coated wire. I tried to keep the original colors, even though they meant nothing for the most part.
The power cord.
(from left to right)
The input blocking capacitor
The bypass capacitor and a resistor for the eye tube.
The 0.04μF capacitor in the measurement circuit.
The 500Ω balancing resistor,
The two across-the-line capacitors on the transformer.
The neon panel lamp.
The neon panel lamp resistor.
The main DC filter.
The filter capacitor was an unusual 5μF @ 700VDC capacitor. I made one from two 10μF @ 450 units, enclosed in a piece of heat shrink. A red band was placed to indicate positive. I think it turned out ok.
The only thing on the top that was replaced (other than wire) is a resistor for the eye tube, mounted directly on the socket.
Miscellaneous:
Knobs, most of them were stripped out.
Screws for the pointer because they snapped when I took it off for cleaning. I used #4 flathead screws here. They sit slightly lower in the pointer than the originals, which were the size of whatever Olson had on hand at the time.
Screws for the face because they were all missing. I assume these were also some odd size because M2.5 was slightly too small and M3 was slightly too large. I ended up going with M3 and just giving it a little elbow grease.
Screws for the back - no idea what these were, I just found something that worked. I think what I used was duplex screws. Who knows, they were in my parts bin and worked-ish.
Next up: Does it work?
Next part of this series: https://wereboar.com … -and-final-thoughts/
Previous part of this series: https://wereboar.com … ith-parts-and-wires/
- 2024
- Dec
- 27
An Olson TE-189 C-R Analyzer - Rebuild, part 3 - finishing up with parts and wires.
This unit has been one of the more interesting devices I’ve picked up at a show. It’s not age related problems, it’s poor build quality from the get go. I think I’ve said it before, but I wonder how this thing got in such a bad state - were these even sold as kits? All of the screws were coated with some odd loctite material, so it appears to have come at least partially assembled…
Regardless, after waiting for the correct wire, I got started again. The wire went on quite the adventure, from Illinois to Ohio, where it visited some suburbs of Columbus. It headed out to Kansas City and visited both states that city occupies before heading to Indianapolis, and finally back to Columbus where it didn’t get delivered. I actually ordered some more wire and got that first - even though the vendor shipped me the wrong gauge! It will still work, however, so onward!
The last portion that really needed rewiring was around the input area:
I did find out that the terminals in that big capacitor are just sitting in little solder pots, so I took the opportunity to clean up a blobby one.
Along the way, I did the meter wiring:
and the potentiometers:
And that’s it. We’re left with a cleaner looking chassis:
and all that’s left is to apply the labels.
A little bit of discussion on what was replaced in the next part, and then for the test. Stay tuned!
Next part of this series: https://wereboar.com … tually-was-replaced/
Previous part of this series: https://wereboar.com … r-the-waiting-game//
- 2024
- Dec
- 26
Selling something and you’ve asked AI to write the description? Good luck!
Do you buy any vintage equipment online, especially from a certain auction site? While this is probably a foolish thing to do because of the prices - sometimes you can find a very unique piece or a great deal on something you’ve wanted. Sometimes, very rarely sometimes.
However…one of the things I’ve noticed is the descriptions of the items have changed. Most used to be “I don’t know exactly what this is or how to test it. Assuming it’s non-working” or something along those lines. A fair assessment for a non-tech person.
But now, AI is writing things for people and it’s hilarious, but annoying because it’s now more valuable because it’s always “widely used in industry,” “well know for their stability,” or some nonsense. No, it’s a hobbyist piece or something made by a company that went out of business in 1974 because they no longer competed on the market.
There’s some serious SNAD material here, and if a dishonest person wanted to get stuff it would be easy enough to do as eBay seems to prefer the buyer’s word over the seller.
But when an unsuspecting buyer thinks they’re getting a device that does digital QAM/Digital Video because the seller just AI wrote some garbage and all they receive is an ancient Leader audio generator that wasn’t great when new - someone isn’t going to like the results.
If you’re selling something and you have no idea what it is, ask a friend. If you don’t have a friend, do 5 minutes of research and find out what it is. Copy the manufacturer’s boilerplate if you need to.
Just don’t tell AI “Write me a description of a Doo-More Signal Generator so I can sell it.” You’re going to get trash, and possibly a strike on your sales.
Just sayin.
- 2024
- Dec
- 22
A look back at 2024’s hamfest and shows.
As we say goodbye to 2024, I took a look at the shows I attended - there were quite a few of them this year, and it surprises me how many of them are in Ohio and the surrounding area. Had time allowed, I could have attended more, but one a month (or thereabouts) is a good schedule. To wrap the year up, here’s a link to all of the pictures from these shows.
I’m looking forward to the coming year’s schedule - you can find that here.
I’ll see you at the show!
Sunday Creek Amateur Radio Federation Hamfest
Event photos: https://wereboar.com … ek-arf-hamfest-2024/
Cuyahoga Falls Amateur Radio Club Hamfest
Event photos: https://wereboar.com … ahoga-falls-hamfest/
TUSCO ARC Hamfest
Event photos: https://wereboar.com … 4-tusco-arc-hamfest/
Dayton Hamvention
Friday photos: https://wereboar.com … 24-fridays-pictures/
Saturday photos: https://wereboar.com … -saturdays-pictures/
Sunday photos: https://wereboar.com … 24-sundays-pictures/
Breezeshooter’s Hamfest
Event photos: https://wereboar.com … ooters-2024-hamfest/
Columbus (OH) Hamfest
Event photos: https://wereboar.com … lumbus-2024-hamfest/
Johnstown Swapper’s Day
Event photos: https://wereboar.com … nstown-swappers-day/
Findlay Radio Club Hamfest
Event photos: https://wereboar.com … o-club-2024-hamfest/
The Cleveland Hamfest and Computer Show
Event photos: https://wereboar.com … 4-cleveland-hamfest/
The Scioto Valley Amateur Radio Club Hamfest
Event photos: https://wereboar.com … o-club-hamfest-2024/
MARC Hamfest
Event photos: https://wereboar.com … e-marc-2024-hamfest/
Fort Wayne Hamfest
Event photos: https://wereboar.com … -fort-wayne-hamfest/
Scott Antique Market - November
Event photos: https://wereboar.com … cott-antique-market/
- 2024
- Dec
- 19
The December Scott Antique Market
The December Scott Antique Market is happening this weekend at the Columbus (Ohio) State Fairgrounds / Expo Center. This is the last show I attend for the year, and I’ll have pictures and a year-end wrapup shortly after.
This show usually has a lot of #radio and other antique electrical and related goods, as well as your standard selection of antiques and other related merchandise. Doors usually open at 9AM on Saturday, but always check before you go.
Admission to the show is free, but the expo charges parking per car.
Scott Antique Market - December
Ohio Expo Center (State Fairgrounds)
717 E 17th Ave
Columbus, OH 43211
December 21 and 22
Hours vary by day, check before you go.
- 2024
- Dec
- 15
An Olson TE-189 C-R Analyzer - The Waiting Game.
I was hoping to present a test and performance post for you by now, but the post office isn’t cooperating with me. I ordered some various colors of wire to finish the rebuild (and have some on hand for later use,) but the materials I ordered have decided to take a tour of a few states as well as the East side of Columbus. It’s visited a couple of places that it had no reason to go. Tonight I got notification that it’s in Kansas. (It went to Kansas again, this time from Kansas City, KS to Kansas City, MO…I’m going to wait until after Christmas and if it’s not here consider it lost.)
(It made it back to Columbus, then to the city where I work…and then vanished. I ordered a short piece to continue the project, the company I bought the wire from eventually considered it lost and replaced it all. I then received the original package in March 2025 - but the post office doesn’t know how, why, or even where it is right now!)
For now, I have the line cord and the 500Ω balancing resistor laid out alongside the tubes. They await the final wire I need for this build.
I have some time off over the holiday, so perhaps I’ll have received it by then. We’ll see - stay tuned!
Next part of this series: https://wereboar.com … ith-parts-and-wires/
Previous part of this series: https://wereboar.com … ace-some-capacitors/
- 2024
- Dec
- 15
A Waterman OCA-11A “industrial / pocket” oscilloscope - Part 2: Tubes!
I picked this device up at the MARC hamfest in North Canton. The seller stated “Someone removed all the tubes except one” and he was right. 4 12AX7 and 1 6U10 were required to fill all of the sockets again.
This is the device in question. It looks like it requires both a horizontal and vertical input, but I’m not sure.
Thanks to Bob @ hamtubes.com, I was able to acquire the necessary tubes. I’m not sure why they were removed, they aren’t really that much unless you want old RCA branded 12AX7. The 6U10 compactron isn’t expensive at all. I chose Russian and Chinese 12AX7 because this is an instrument, not an amplifier.
A little bit about one of these tubes: the 6U10 “”compactron” was the last gasp of the tube industry. Packing up to 4 devices in a single shell, this was an attempt by GE to reduce the number of tubes required for a television set. Had these come out before the transistor era started, we might have seen more elements in a single tube, but we didn’t, and the rest is history. This particular device contains 3 triodes - probably why it was removed by the previous owner.
So let’s open it up and populate things. Indeed, it is empty in here:
And now it’s full:
Some of these tubes were hard to get in to their respective sockets.
I did notice the one remaining tube was Waterman branded. That’s too bad, the others probably were too. I wonder who made these - maybe I’ll pull it out sometime and see if it has an EIA code on it.
Ok, so…let’s try it. Checking across the line cord I get…nothing. Mmmmm that’s not good. No external fuses, so what’s wrong here. Start with the line cord, it goes to the fuse, then to the switch, then to the ….nothing.
Power switch is bad. It’s pretty corroded, so no surprise. Well, I’m out of time for this particular device at the moment, so a note and set it aside. Stay tuned for the next part where we turn it on for reals!
Next part of this series: Coming soon.
Previous part of this series: https://wereboar.com … pocket-oscilloscope/
- 2024
- Dec
- 13
The Heathkit IO-10 Oscilloscope - Part 1: Observations
In my quest to find a small bench scope, I picked up a couple of different models for a decent price. This IO-10 was a negotiated item - I mostly didn’t want to pay the asking price because it had a missing fuse holder cap, and that usually means that someone was working in the device trying to figure out why the fuse was blowing. Other than that, the device looked to be in pretty decent physical condition.
It arrived today in a box that, when new, was just a suggestion of cardboard and it didn’t really survive the trip. Uh oh. It was crushed somewhat and I expected the worst.
Opening revealed an apparently mostly intact device:
There was a lot of debris in the device. Paper, leaves, etc. I understand it had been sitting in a garage, but was it being used to shred leaves? Fortunately, all of the tubes are still in their sockets but you can tell they tried to vibrate loose. Most are the original Mullard, but there’s a couple of RCA, a Sylvania, and a GE device in here in the places you’d expect. Power supply, mostly. All covered with debris.
Most of the controls and one of the terminals are just frozen with goo and damp corrosion. This is going to need a good dousing with alcohol and tuner lube. I can’t even turn the power control. It’s locked.
Unfortunately, because it wasn’t packed properly, it got damaged at some point, probably dropped on it’s corner. I am sad because this thing was otherwise in 8/10 shape. I’m going to ask a friend who does metalwork for some advice on knocking this dent out.
It doesn’t appear to have been touched except for tubes, and the one part seems to indicate this was made sometime around 1968. So, it’s not terribly old - the electrolytics may be still good (but unlikely due to garage storage.) Everything else is disc, so this shouldn’t need much more than some good filter capacitors and maybe a few of those carbon resistors replaced.
This one is going to need to wait a while before I get it on the bench, as the holidays and some work-related items are going to take priority. Check back soon for more on this device!
Next part of this series: Coming Soon.
- 2024
- Dec
- 13
Tales from the eBay universe.
For the most part, the stuff I see on eBay that I like is reasonably priced. Some is excellent, some is “Let me offer you a little less”
There there’s this one. Maybe the person doesn’t know what they are offering, or maybe they think because it’s “old” that it’s valuable beyond compare. Who knows, but this thing looks like B.O.B. from the Black Hole. I can’t really tell what’s happened to it beyond it’s Seen Some Stuff. Bent cabinet, bent control shafts, but surprisingly it still works. This is a $5 hamfest “Please take me” sale.
$250? Maybe if it was still in the box, and the box wasn’t opened.
- 2024
- Dec
- 13
The Heathkit IO-21 Oscilloscope - Part 1: Observations
I’ve been wanting a small, AC powered oscilloscope for the bench, something that can do tube stuff without caring if you accidentally hit B+ for a second. Heathkit made several different styles that fit the bill, and I managed to run across this decent looking IO-21 3” scope for a reasonable amount.
It’s difficult to find one of these both in OK condition, and for a decent price. Like most items, people see “TOOOOB,” get some chatbot to write them garbage about how it’s a widely used accurate piece of equipment good for your toolbox, and slap a high price on it. It’s not, it’s something useful for a few of us, and the rest go and get one of those $60 Zotec Scopemeters for our toolbag.
Regardless, this is in ok shape. Most of the parts are there save for a terminal cap, which is no problem. I have many of those of the correct type from dead Heathkit devices of electronics past. It’s dirty, but that’s to be expected.
Note that many will label these as 10-21, but all scopes from Heathkit of this era were “IO” series.
The side
is a bit scruffy, and the back exhibits some broken plastic on the direct vertical inputs.
Those are just jacks, so they can be replaced if need be.
Time to take the back off…first impressions were this was built from a kit, and decently built.
But here’s a thing. The fuseholder was empty. That’s not a good sign, but here’s another fuseholder inside.
It’s not even really soldered, the one wire is just wrapped around the lower terminal of the mounted jack. Wut?
There’s a fuse in it, so I remove the extra fuseholder and put the fuse in the actual holder. Some have suggested that maybe someone was trying to parallel a fuse (maybe…) or didn’t have the correct physical size. Both are 3AG, so that’s not the case. I don’t know what was going on here, but hey - bonus fuseholder.
You’ll also note the large amount of insect debris here. That got a visit from Mister Shop Vac before proceeding.
The tube set is a mix of RCA made RCA branded, GE Made Sylvania Branded, and some washed tubes. This probably would have come with Mullard made Heath branded tubes, so this guy has seen a lot of use.
The ones in the back are 12AU7, but have nothing on them. No name, numbers, anything…chances are these came from a bulk reseller that would take used tubes, wash them of any marks, (maybe) test them and then (maybe) rebrand them as their own. That they work is amazing in itself.
Of note here is some capacitors used as filters for the CRT high voltage. 2x 1600V @ 0.01μF are prime candidates for being a Popping Patty, so they’ll need to go even if nothing else is wrong.
The bottom similarly reveals some capacitors that probably are going to need consideration, but overall it’s nicely built with just one add-in part that I assume was put there by someone other than the original builder.
Does it work? Some basic checks were made and I plugged it in. This device is a 6V parallel string for the tubes, and the 12AU7 are all folded over so they run on 6V. These tubes have their heaters split in the middle so you can operate on 12 or 6V, depending on your application. On almost all of them, only one side lit so a bit of wiggling later (dirty sockets) here comes a trace. It’s about as bright as it was when new, which is to say a bright room washes it out. But it’s there, and that’s the important thing - a dead CRT means a dead unit.
Stay tuned for the next part of this series, some cleanup and basic identification for parts that absolutely need to go.
Next part of this series: Coming soon.