- 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: Coming soon
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: Coming soon
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: Coming soon
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: Coming soon
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!
- 2023
- Dec
- 9
I have to fix the equipment before I fix the equipment.
Earlier this year, I went to the Cuyahoga Falls hamfest and brought home a Regency EC-175 frequency counter. This device has a OCXO in order to maintain a low PPM deviation for FCC compliance use. It’s really kind of an odd piece for Regency, and was going for next to nothing.
https://wereboar.com … yahoga-falls-hamfest
The Regency counter works, but is off by a considerable margin. I suspect this is probably just the 10MHz oven needing some adjustment.
My plan was to poke around inside of it and determine what was what, as I don’t have a service or operators manual. (I’ve since found an operators manual and will post it as soon as possible.) I was planning on using a cheap Lodestar signal generator and my Fluke 1910A 125MHz frequency counter to try and bring the Regency into adjustment.
So I set up, and…the Fluke counter doesn’t work. It will work as an up-counter, but won’t count frequency input. Hitting the “CHK” button, I get nothing:
This should be showing me the internal 10MHz clock. I play with various things and get nothing.
Time to open it up.
Nothing looks burnt. The section I need is underneath the RF cover, so off it comes. The parts in question, according to the schematic, are at the back of the unit near the metal backplate.
But before we get into those parts, a quick power supply check is in order. There are two voltages, +5 and -12.
+5 = 5.02
-12 = -11.80
The -12V is a TO-5 can device, and is pretty warm. I’m not sure if that’s supposed to be like that, but since -12 isn’t in the oscillator circuit, I’m going to ignore it for now. The logic supply of +5 is fine, however, so we’re good there.
The parts I’m going to be interested in here are :
U5
Q7 (under the heat-shrunk connector in the foreground)
Q8
Y1
I’m not really worried about U9 here because if I don’t have any 10MHz, I’m not goign to have any 1MHz. U9 is a divide by 10, so we’ll worry about that when and if 10MHz is available.
U5 pin 10 should be 10MHz. There’s nothing, so move back.
Q7 Base should be 10MHz. There’s nothing there, either.
I’m now going to switch the counter to EXT mode, as to remove those two parts from the circuit.
Q8 is an interesting part here. It’s a JFET, and the schematic appears to show a 2N3819. (It actually looks like SN3819, which isn’t a valid number.) However, that’s not what’s in the unit. I have a J310 VHF JFET which has a different pinout.
Always be careful, sometimes manuals you find online contain older or newer revisions of the device you’re using!
This confused me at first, because I was trying to test it like a 2N3819 and was getting a short on Gate to Drain, Pin 2 to 1. What I was actually reading was Drain to Source, which should be a somewhat low resistance. In this case, I had 37 ohms. That’s probably fine for a JFET, since Drain and Source are mostly the same slab of silicon. Without pulling this guy out and testing in an active tester, I assume it’s good.
No capacitors appear to be shorted. The few resistors in the circuit are fine for what they are, and are well within tolerance.
That just leaves the crystal. I don’t really have any way of testing it. I can try capacitance, but the resistors in the circuit will ruin that low pF measurement, so the only way is to pull it out.
The conclusion is the oscillator isn’t. The assumption here is the crystal is bad. Maybe cracked or internally damaged from time or handing? I don’t know - I’m going to try and obtain something similar to swap in and see if it works. There’s also a possibility I could find a cheap TXCO or OXCO to put in the area where Fluke would have mounted a TXCO, which should provide a better device.
That assumes the device is operational up front. These aren’t known for being reliable as they age, perhaps I’m just wasting my time with this. But I know where the problem lies, so there’s no harm in getting a few dollars in parts to try and make it work again.
- 2023
- Dec
- 3
An MMD1 8080 Trainer
This guy was given to me, well, probably in the late 90s because it was missing it’s 8224 clock chip. The person that gave it to me, since deceased, didn’t really want to go through the trouble of finding one so he asked if I’d like the device instead. Sure, why not.
I eventually found an 8224 on a device at a show, and put it in recently. I then realized that, unlike most other trainers, this one has no LED numeric displays! Well… the HALT LED will light and extinguish if I play with the keyboard, so I assume something is going on since it didn’t do that before. I thought about dumping the monitor ROM, but someone has already done that. I also need to investigate the power supply, it has a very loud hum and may need some modernization.
It’s nothing really special, just another one of many 8080 trainers that were available on the market. It will go beside my FOX Z80 trainer and my BellMAC 8 device for display. After it gets a little cleanup, of course, the thing was filthy when I got it and I have not done a thing with it.
The monitor ROM and some other information is presented here: http://www.decodesystems.com/mmd1.html
- 2023
- Dec
- 1
Random board shot: The Bell (Model?) Telephone Desk Speaker
My grandfather worked for the Bell System Long Lines division for his entire career, and I worked for one of Ma’s manufacturing locations just before it got spun off into the atrocity called Lucent Technologies, so Bell memorabilia is kind of an interesting thing to me. I remember all kinds of things in my grandparent’s home that you couldn’t necessarily get as a consumer - one of those being desk speakers on every phone in the place. And there were many many phones, apparently being wired without incurring the Bell System’s multi-device charges!
This desk speaker, while not one of his (all of those vanished…) it’s very similar. Not sure of the model here, it resembles a 107A but has an on/off switch along side the regular volume control.
The old Bell System logo resides here, being much more visually appealing than the later, minimal logo.
The inside, of course, is all Bell parts. Speakers and microphone were made by or for Bell, capacitors from the Hawthorne Works, and even the plastic case and metal parts were probably stamped out and molded by a Bell facility. It’s a simple line powered amp and mic, used in place of the handset.
My mother tells me stories of having her father (my grandfather) call in from where ever he was working at the time (he traveled the country doing line installs) and having the entire family gather around one of these speakers. When you worked for the phone company, making long-distance calls didn’t cost you anything from the job site, apparently!
The most interesting thing about this device, of course, is the PCB. Right there it is, the orange Textolite “T” indicating that the raw circuit board itself was made in Coshocton at the 2nd Street GE plant, just a stone’s throw from where my grandfather’s depot was based.
It amazes me how far, and how near products from this plant roamed. They’re in almost everything made in the USA up until the 80s. All of that, of course, is gone - something we’ll probably be sorry we did one day (soon!)