- 2024
- Aug
- 22
The NRI (Conar 200) “Appliance Tester”
I’m not sure what fascinates me about these little test boxes - maybe it’s the attempt by the manufacturer to put as many functions into a small a space as they can. Regardless, this little test box is one of those devices. Yes, it’s a device that could be replaced by a simple digital multimeter and a couple of cables, but this was supposed to be an all-in-one device with all of the necessary connections to do the job at hand.
This device is a tester from NRI, or National Radio Institute - a former school by mail organization. This device was probably included, unassembled, as part of one of the courses. It’s state gave you a chance to learn assembly and soldering, as well as some circuit basics. It was later marketed on it’s own as the Conar 200, Conar being the consumer imprint of NRI where you could purchase NRI devices without the need for the coursework.
This device came from the 2024 Cuyahoga Falls Hamfest, and was $3. I didn’t really buy it for the test box itself, but more the real copper clips and probes that were in the storage compartment. The device itself was interesting enough (but smells horribly of basement!) that I decided to check it out a little.
At first glance, it appears to be a multimeter - and it is. It features a battery powered two-scale ohmmeter, a two-scale voltmeter, and a single scale ammeter. The volts and amps functions are simple metered measurements without any kind of filtering or scaling save that necessary to make it a high or low range. It has pin jacks for probing the device under test, and a socket so you can do direct amp measurements. That’s all.
It’s a very simple, unisolated device. The cordset is live when the probes are, and vice-versa.
The back of the device is fairly simple as well. A few resistors, a potentiometer, the meter connections, fuse, and some sockets are all you’ll find, along with the battery for the ohms function (removed in this image.) The wire is of fairly small gauge for 20A, so this isn’t something you’d want to run for a long period of time. It’s really about as simple as you can get, and is a pretty good meter for just having around and not worrying about batteries (for the most part.)
The battery in the device is a little odd, the kit required that you solder it in. There’s no battery holder save the spring clip. You’re absolutely right in thinking that you’re not supposed to solder on batteries, and that’s for multiple reasons. The two biggest reasons is the electrodes aren’t really meant to handle heat like that, and in newer batteries the electrolyte is wet(ter.) Heat could potentially cause it to burst or burn.
The battery in this one had leaked over the years, but fortunately for me it was a carbon cell. The electrolyte caused oxidation on the battery surface, but there’s no alkaline corrosion mess all over the place.
I’ll probably stick a battery in it at some point and see if it works. I can’t believe it doesn’t, there’s nothing there to not work!
- 2024
- Aug
- 14
Has it really been 30 years?
It’s been a while, hasn’t it, old friend? I didn’t think you worked anymore, but it looks like you’re still sitting there patiently waiting for input. Your power connector is loose, so we need to see about that, but I’ll see if I can find your manual and make some magic.
- 2024
- Aug
- 12
The PACO B-10 Battery Eliminator and Charger
I picked this guy up at the Columbus Hamfest for $5. It claims to be a power supply of sorts, and a battery charger. It is lopsidedly heavy. So at minimum, there’s a nice big transformer in the thing, if all else fails.
It’s fairly unassuming from the outside. The front has the business end of the device - two meters, output terminals, output adjust, and a couple of switches.
As a note, this thing is only 6 and 12 volt, with a little wiggle room.
The back and sides are just as unassuming, nothing except some vents, the cord, and a serial number.
You’d think there’s some sort of regulation in this device, right? Wrong.
There’s pretty much nothing inside of this guy. Apparently, the only regulation is YOU, and that’s by turning the dial on the front of the device!
Inside, it’s a history lesson in electronics.
Lots of cloth-coated solid wire and big wads of copper and metal make up this device.
Here’s the power transformer, two giant sized but comparatively small value capacitors, and a giant choke in the middle that hides the voltage adjust tap.
Here’s some boom cans, aka old capacitors. These claim to have been made by Pyramid in 1958. 6000uF at 20V - these can be replaced by 6800@25 for about $4 each, and two of them would fit handily in the space taken by one, with room to spare!
No, I’m not going to try and charge them!
Last, we have the business end of the device. The rectifiers - in this case, giant selenium plates. I wonder what kind of condition these things are in. Are rotten eggs in my future?
This is certainly a product of it’s time - it’s interesting in that it’s a battery charger not made by one of the companies that did such things at the time, but also tries to be a primitive DC supply for device bench testing. Now, of course, we’d just grab a 20A switcher, but this thing was what you had in the 50s.
Is it going to go back in service? Not until I can at least get some new capacitors, but even then - it may just end up as nice power supply transformer in a box. Who knows where this is going…
These pictures were accepted by Radiomuseum for one of their exhibits. Check them out! https://www.radiomus … minator_kit_b.html#a
- 2024
- Aug
- 11
These giant selenium rectifier plates
I recently picked up an ancient PACO B-10 “Power Supply / Battery Charger” from the Columbus Hamfest. I wasn’t sure what was in the thing, but turns out there’s not much.
These giant selenium plates, however, are a thing of ancient beauty. The whole thing looks like it’s era, a mash of wire, transformers, and rust. Stay tuned for a more complete teardown and other photos of this device.
- 2024
- Aug
- 11
I’ve added a mastodon feed to the blog.
I’ve had commenting here off for some time, mostly due to the spam problem. Flatpress is a great system, but all comment platforms, unless heavily moderated, are spam magnets.
However, I wanted a way to communicate with people that may be reading this blog. I’ve had my LinkedIn profile connected for some time, but that’s not an accessible platform for most. Mastodon, however, is.
Mastodon is one of the twitter-likes that came out of the old Gnu Social era. It’s exactly what you think it is, a feed full of short posts by multiple people, and you can follow and interact with anyone that’s a part of the “fediverse,” a loose-linked conglomeration of various servers and people.
That’s not to say Mastodon doesn’t have it’s own issues, the originator of the system has some hangups that prevented conversations linked to other servers because he didn’t like the content, and it certainly has a very political leaning if you dive into the main feed. That’s not what I’m here for - I simply want to post my weird electronics and give people a way to go “Where did you get that thing?”
If you’d like, check it out: https://mastodon.social/@wereboar - not everything here has been mirrored there, but going forward - it will be.
Thanks for hanging out with this little pig, and I’ll see you at the hamfest!
- 2024
- Aug
- 7
Pretty good for just pulling it out of a junk bin.
Here’s the decade box I pulled out of a box of parts and junk at the recent Columbus Hamfest.
Granted, my old Keithley Meter hasn’t been calibrated in many years, but … 2 Ohms? I’ll take it!
- 2024
- Aug
- 7
The 2024 Coolspring Power Museum Show
The Coolspring Power Museum is a large display ground consisting of member-maintained static displays consisting of everything from small oilfield engines to a giant across-the-state natural gas compressor engine, with everything in-between. Much of it’s up and running for the show, with other stuff in various states of rebuild or runs during a demonstration time. It’s a fascinating place, and they have engines and displays that you’re literally not going to see anywhere else - at least not in this condition!
All of the images here are of those static displays. There are other items that pull in for display during the show, but that’s primarily through the week. Saturday is the last day of the show, so most of that was gone by the time we arrived. Still…there’s so much to look at, and we’ll probably head back for the fall show this year as well. This one is well worth the time to visit if you have interest in old engines.
As with the MVSTA show, I don’t have much to say about these pictures - so here they are, in all of their greasy glory.
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You can view the museum’s web page here.
- 2024
- Aug
- 7
The 2024 Miami Valley Steam Threshers Association Show
While this, and other engine shows I attend aren’t necessarily electrical in nature, they are certainly prime examples of old technology. I’ve always found the mechanics of such devices to be fascinating, and worth my attention.
The MVSTA show is one that happens on the Western edge of Columbus every year, and I try to make it out there at least every few years. This year’s show was bright and sunny with no threat of rain anywhere. Prime viewing time for all of the mechanical eye candy that showed up.
I don’t have much to say about these pictures, so no annotations.
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Visit this link for more information on their shows.
- 2024
- Aug
- 7
Have you ever wondered what’s inside of that device?
Worry no more. With the help of Google Translate, you can finally see what’s actually inside that cheap Chinese solder pot you bought from AliExpress.
That magic “Heating Stuff” - it’s like the smoke in resistors.
- 2024
- Aug
- 7
The Columbus 2024 Hamfest
This year’s show was maybe 2/3 the size of normal - I suspect the dangerous looking skies kept some people away, but fortunately the rain held off for the show. It was, however, sticky enough that you could probably have put a straw in the air and drank some.
There were still some interesting things to be found at this year’s show, and some good deals to be had. This is what I saw this year:
