- 2024
- Jan
- 14
The Sunday Creek Hamfest has come and gone,
And I have to say it was a pretty good little show. The weather wasn’t planning on agreeing on the ride down, but it turned out to be just a skiff of snow and cold, windy weather. There were maybe a couple dozen vendors, and a packed house full of guests to the point where cars had to shuffle so others could leave.
While I only spent an hour there, I walked out with some good stuff as did my fellow show-goer. I’m working on processing pictures, and will post those soon. In the meantime, bask in the green glow of a magic eye from one of the devices I went home with.
- 2024
- Jan
- 8
Stabilizing the oscillator in the IM-1212 Meter, part 2
One of the issues with the IM-1212 and it’s clones is that it drifts all over the place, and part of that is the oscillator that actually does the counting for the display. This is an attempt to replace that section with better parts to see if it’s any more stable. I started this with this previous post, and present my findings here.
We start by identifying the components of interest and removing the board:
In the oscillator circuit, other than the transistors, are the following passives:
15k
8.2k
3.3k
3.3k
0.0022uF
0.0022uF
15k Potentiometer
We’re not going to replace the pot, but all of the other components are going to be replaced by film and/or temperature stable to 25ppm components.
The sharper-eyed among you will have already seen an issue. There’s no 15k resistor identified here, and I’ll talk about this a bit later in the process.
Before taking the board out, I let it warm up and preset the oscillator to it’s suggested 85 count.
Getting the board out isn’t too bad. There are 6 screws, three solders, and a clamp.
The screws are the ground lug for the power cord on the back panel, the two screws that hold the transformer down, and one screw each in the remaining corners. One of the screws is under the switch assembly and can just be seen by the red input jack, so you’ll need something relatively thin and long for this one. They all appear to be the same size.
Next are the three jacks on the input. I unsoldered these at the front panel itself, but the white wire was long and flopped around and broke because it is solid wire. Not a big deal there.
Last, is the clamp for the power cord on the back panel. This is just squeeze it with pliers and work it out. I left the power cord attached to the unit and just pulled it through the bottom case so I had enough room to work, and used the ground lug screw and nut to temporarily hold the transformer down as not to break the relatively fragile connections to the PCB.
Before getting started, I did an inspection of the board. There were a number of bad solders on some of the components - mostly things with thick leads like the potentiometers. I took a minute to clean those up before getting started.
Removing the parts is relatively easy, this being a single sided board. A soldapult and some wick made short work of the old solder, and that’s when I noticed the 15k resistor wasn’t.
The schematic indicates 15k, as does the board - and another unit I have has the correct 15k part in it. I have to wonder why this was there - did the original builder not get the correct part, or was it broken during assembly? Who knows - but it didn’t really matter as the device worked.
Interesting.
The rest of the parts are replaced without issue, and the correct 15k is placed where indicated.
There’s not a lot of current or voltage here, so I wasn’t particularly concerned with the size of the resistors.
After doing a precursory check of parts, solders, and whatnot, I powered the device up on the bench. The oscillator count was quite different, so my replacements had some effect.
Some warmup time later and I adjusted the oscillator to the correct value:
Putting it back together and:
It’s already drifting. I set it back to 85 and let it set until the next day.
It didn’t do a thing. I will say, however, that it seems easier to adjust it back - there’s not as much play in the overall adjustment - you can set it and it generally stays there until the temperature changes.
So, my conclusions? This whole thing probably would need rebuilt with modern components in order to maintain any stability in measurement. For now, it’s just going to be sitting in a rack on all the time measuring the 12V rail of a power supply so … it is what it is, I guess.
- 2024
- Jan
- 3
Mistakes were made - a long long time ago.
2024 brings this device from years ago, which I opened to find a mistake in assembly. This Bell & Howell IMD-202-2 NIXIE meter has a 10k resistor in the oscillator circuit, where the board and schematic specified a 15k.
The carbon resistor used was so sloppy that it didn’t really matter what went in there, of course, as long as it was close enough to the value specified. The part had long since drifted out of tolerance, the upper limit being 11k - this one read 11.64k!
I have to wonder if the person building this kit did that accidentally, or on purpose because they didn’t have the correct part, or maybe they chose it to correct something else. I’ll never know, but a 15k precision went in to the circuit and seems to be working without issue. I have to assume it was simply an honest mistake, as I didn’t see any evidence of rework on the bottom of the board.
Stay tuned for my findings on trying to fix some of this device’s drift.
- 2023
- Dec
- 23
An odd little part - single plate selenium rectifier.
Here’s a weird little part I picked up at a show, it was in a “Take as many as you want” box. It’s a single plate selenium rectifier. These components were widely used in the time between tube rectification and silicon rectification, but fell out of service because silicon diodes are simply much more efficient at rectifying AC voltages and providing other diode services.
It’s marked as Federal 179545. It has a forward DC resistance of about 88k, and a reverse resistance of 792k. So what would this have been used for? Bias voltages maybe? Or a diode that would blow if the current went higher than anticipated? I’m not sure.
It’s just a cool piece of yesterday’s technology at this point.
- 2023
- Dec
- 22
Stabilizing the oscillator in the IM-1212 Meter
One of the problems with the Heathkit IM-1212 / Bell&Howell IMD-202-2 meter is the oscillator is made of crap-tier parts, and has a problem drifting all over the place. 10% carbon comp resistors and who knows what capacitors make up the parts complement. While that was probably fine for the age, a few dollars more could have made this at least a decent instrument for it’s time.
The main problem here is the parts are not temperature stable. For example, the meter I just recently acquired (see https://wereboar.com … ter-for-some-reason/) came in to the shop cold from being in a delivery van. It was allowed to warm up a little and plugged in. Oscillator was sitting at 94. It drifted down to 79 as it warmed up, and then back up to 88 - all in the course of an hour. That’s not good when you’re relying on that signal to generate the timing for your counts!
There’s not much to the oscillator. A couple of transistors for the oscillator itself, an inhibit transistor to start and stop the counter, and the passives that make up the oscillator circuit itself.
Here’s what we’re interested in:
There are two 3.3k 5% resistors, a 15k 10% resistor, an 8.2k 5% resistor, and two 0.0022uF capacitors. What’s the PPM drift for temperature on any of these parts? “Yes.”
So, off to Mouser we go!
Are these parts overkill? You bet. These are “Parts exceed value of device.” But they’re not really that expensive these days. So…why not? It’s mostly to satisfy my own curiosity to see if it really does make a difference in how the unit operates. If not…oh well, I learn something either way.
(The 15k pot may get replaced with something better - I was thinking of bringing it out to the back panel somehow, since it’s the main pain point.)
I do have some lesser quality (but still better than what’s in there!) parts, if I get ambitious I may replace some stuff before the actual parts arrive. Stay tuned!
- 2023
- Dec
- 21
Another IM-1212 Meter. For some reason.
Not really, I wanted to have one for both the 5V and 12V rails on my network rack. Sure, I could just switch back and forth between the two voltages, but where’s the cool in that?
This one is actually a Bell & Howell IMD-202-2, and has a much cooler aqua blue case. It’s in nice shape, and for some reason didn’t get bid to oblivion like others I’ve seen on that not-as-popular auction site. (Last one I tried to get started at a reasonable $8 and went to almost $70 + shipping. That’s insane!)
This one also came with a manual, which I may try to scan and place here. There’s some confusion as to if the manuals for Heathkit-derived instruments are under copyright, so we’ll see.
This one needs calibrated, of course. The oscillator adjust drifted from 94 when I turned it on, to 79, then back to 85 as things stabilized. 85, of course, is where it’s supposed to be but I have no idea where the zero and DC pots are currently set. It’s currently running with a slow AC on it just to warm up, and I’ll do a cal on it this weekend.
I’d like to find a few more since the ZM1000 NIXIE tubes, once common as dirt, are now scarce because clocks.
- 2023
- Dec
- 17
December 2023’s Scott Antique Market.
There wasn’t quite as much at the December show as opposed to the November show, but there was still a lot to look at. I picked up an oil lamp to match one I already have, and took the Humble Oil tiger with the horse pee stickers home. The stickers came off with some coaxing from a heat gun, so I’m pleased with that. My fellow show-goer bought some cheesy Christmas LPs because you can’t have Christmas without random “Why the eff is that?” records playing on the turntable. A Stoneman Christmas, anyone?
The next show is in January. There’s a small hamfest happening about the same time, so I will probably go to that instead, unless they are happening on different weekends (which they are!)
- 2023
- Dec
- 15
All of the documents currently in wereboar’s archive.
I’ve posted a number of manuals and things over the past few years, and they’re scattered around the site. Here’s all of them to date, this list will be updated as new ones are added.
(These open in OX Drive, my hosting provider’s file share service.)
Blonder-Tongue B-9 Audio Baton SAMS
https://privateemail … 01676/1/8/NDY/NDYvOA
Blonder-Tongue B-9 Audio Baton operator’s manual - I’m not sure where this came from save it’s a scan of a print.
https://privateemail … 42ef/1/8/NDY/NDYvMTQ
Burroughs NIXIE catalog 918A (Old B&W Scan)
https://privateemail … 3e93/1/8/NDY/NDYvMTA
Hallicrafters S38C SAMS
https://privateemail … e0ef7/1/8/NDY/NDYvNw
Hallicrafters S41G SAMS
https://privateemail … df524/1/8/NDY/NDYvNQ
Regency EC-175 Frequency Counter
https://privateemail … 36bb6/1/8/NDY/NDYvMQ
SWP Co-Power (x88) Expansion Board Manuals
This is a ZIP download and contains multiple manuals and documents
https://privateemail … 75263/1/8/NDY/NDYvOQ
TechTran 900 Series Disk Drives Operations
https://privateemail … bf632/1/8/NDY/NDYvNg
TechTran External Disk Drives Technial Tips Sheet
https://privateemail … 32b08/1/8/NDY/NDYvMg
CAT WX-250 Weather Radio Digital Interface Document
https://privateemail … a7c61/1/8/NDY/NDYvMw
CAT WX-250 Weather Radio Operations
https://privateemail … 54bbb/1/8/NDY/NDYvNA
Linksys WMLS11b Music Player Information
This ZIP contains all files I could find for the device, as well as the Yahoo! Groups message board dump that I made shortly before shutdown. This is all raw dumps and downloads, grab 7zip to open the archives if you’re using Windows.
https://privateemail … c50d/1/8/NDY/NDYvMTE
Racal-Dana 6000 DVM Operation and Service Manual
https://privateemail … c365/1/8/NDY/NDYvMTI
Racal-Dana 9000 Counter-Timer Operation and Service Manual
https://privateemail … eb40/1/8/NDY/NDYvMTM
Unless specified, the downloads are direct PDF files. More to come as I run across old scans and other useful documents.
Please share, but let them know where you found it. Come visit this little pig!
- 2023
- Dec
- 15
The Regency EC-175 Frequency Counter Manual
I recently acquired (and had a scan request for) the manual for the Regency EC-175 Frequency Counter that I’ve posted about here.
If you’d like a copy, this is the owner/operator/basic service manual for the device. I’m not sure a service manual with schematics was ever released, this manual seems to indicate that it should be sent back to Regency for repair (don’t they all?) However, being a piece of test equipment that was supposed to be used for FCC compliance operation, it’s not surprising that Regency may not have wanted to release service data.
You can find the manual here: https://privateemail … 36bb6/1/8/NDY/NDYvMQ
I’ve also submitted this to the BAMA manual archive https://bama.edebris … com/manuals/regency/. The owner has added it to the site’s manuals for your viewing pleasure.
- 2023
- Dec
- 11
2024 Hamfest List
I try to plan out the shows I want to attend early, that way I have time set aside and don’t need to move things around. This is my tentative list (no means exhaustive for even Ohio shows!) that I may try to attend, weather and time permitting. I’ll post more about the shows as they approach and dates are set.
Dayton, of course, is a will-go no matter what. See you there!
Sunday Creek Amateur Radio Federation Hamfest
Shade Community Center
2380 Old U.S. 33
Shade, OH 45776
January 14 2024
8A-2P-ish
Admission $6
https://www.arrl.org/hamfests/sunday-creek-amateur-radio-federation-hamfest-3
Event photos: https://wereboar.com … ek-arf-hamfest-2024/
Cuyahoga Falls Amateur Radio Club Hamfest
Emidio & Sons Party Center
48 E. Bath Road
Cuyahoga Falls, OH 44221
April 13 2024
8A - 1PM
https://sites.google.com/cfarc.org/cfarc/hamfest
Event photos: https://wereboar.com … ahoga-falls-hamfest/
TUSCO ARC Hamfest
Commercial Building at the Tuscarawas County Fairgrounds
295 South Tuscarawas Ave
Dover, OH 44622
April 27 2024
8A - 1PM
https://www.w8zx.net/hamfest
Event photos: https://wereboar.com … 4-tusco-arc-hamfest/
Dayton Hamvention
Greene County Fair and Expo Center - The Whole Thing
210 Fairground Road
Xenia, OH 45385
May 17 18 19 2024
Hours vary by day, opens at 9AM
https://hamvention.org
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
Butler, PA
Butler Farm Show (Kind of a fairgrounds thing)
625 Evans City Rd
Butler, PA 16001
June 9 2024
8A - 2PM
https://breezeshooters.org/ns/
Event photos: https://wereboar.com … ooters-2024-hamfest/
Van Wert (OH) Hamfest
Van Wert County Fairgrounds
1055 S. Washington Street
Van Wert, OH 45891
July 21 2024
8A - When it’s done
https://w8fy.org/hamfest.html
Event photos: Sorry, didn’t make it to this one, life got in the way.
Columbus (OH) Hamfest
Aladdin Shrine Center
1801 Gateway Cir
Grove City, OH 43123
August 3 2024
8A - 1PMish
https://aladdinshrine.org/hamfest/
Event photos: https://wereboar.com … lumbus-2024-hamfest/
Johnstown Swapper’s Day
Johnstown Community Sportsmen’s Club
7357 Sportsman Club Rd NW
Johnstown, OH 43031
Labor Day Weekend (Fri Sat Sun)
7A - 6P
https://jcscohio.org/swappers-day/
Event photos: https://wereboar.com … nstown-swappers-day/
Findlay Radio Club Hamfest
Hancock County Fairgrounds
1017 E. Sandusky St.
Findlay, Ohio 45839
September 8 2024
8A - 1PM-ish
https://www.findlayradioclub.org/
Event photos: https://wereboar.com … o-club-2024-hamfest/
The Cleveland Hamfest and Computer Show
Berea Fairgrounds, Eastland Entrance
160 Eastland Rd
Berea, OH 44107
September 22 2024
8A - 12P
https://www.hac.org/
Event photos: https://wereboar.com … 4-cleveland-hamfest/
The Scioto Valley Amateur Radio Club Hamfest
Pike County Fairgrounds
311 Mill Street
Piketon, OH 45661
October 5 2024
8A - 12P
https://www.arrl.org/hamfests/scioto-valley-amateur-radio-club-hamfest-2
Event photos: https://wereboar.com … o-club-hamfest-2024/
MARC Hamfest
Military Air Preservation Society Hanger (MAPS)
2620 International Parkway
Green, OH 44232
October 27 2024
8A - 1P
http://w8np.net
Event photos: https://wereboar.com … e-marc-2024-hamfest/
Fort Wayne Hamfest
Allen Country War Memorial Coliseum
4000 Parnell Ave
Fort Wayne, IN 46805
November 16, 17 2024
Hours vary by day, opens at 9AM
https://www.acarts.com/hfmain.htm
Event photos: https://wereboar.com … -fort-wayne-hamfest/
Scott Antique Market - November
Ohio Expo Center (State Fairgrounds)
717 E 17th Ave
Columbus, OH 43211
November 30 and December 1
Hours vary by day, check before you go.
https://www.scottantiquemarket.com/
Event photos: https://wereboar.com … cott-antique-market/
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.
https://www.scottantiquemarket.com/
Event photos: Sorry, didn’t make it to this one - work related things got in the way.
Swapper’s Day and the Scott Antique Market aren’t really hamfests, but you still get a lot of electrical goods at these shows. Swapper’s Day is a large flea market, and Scott is an antique show. The November show is the season opener for the antique market, and you’ll usually have the greatest number of vendors at this show - and will have the best selection of merchandise.
All of the shows have announced time and date, but check before you go!