- 2024
- Dec
- 3
An Olson TE-189 C-R Analyzer - Considerations
I’m getting ready to replace some of the parts in this device, and I decided to take a look at what I’m doing and consider things.
I recently cleaned up an older B&K Capacitor Checker, and (in theory) this device should be a good reference instrument for measuring parts in this device. I decided to check things and it made me wonder if I really should replace all of them. There are some that will most certainly get a new part in their place, but others…
The first is the 400pF mica capacitor. I originally thought this thing was a mod, as it has a capacitor and a trimmer. However, I’ve seen another unit under rebuild and it has the same thing. The trimmer itself is plastic, so there’s no way this thing is approaching 600V, but it adjusted down perfectly and I had a good 400pF on the meter.
The big 4μF was similarly in good condition with this meter.
This one has good ESR and has a big 1k resistor to absorb the brunt of any voltage, so I think this and the 400pF will just be left alone for now. I have replacements in case they do need to go, but they don’t right now.
What does need to go is all of these metal can parts, especially the across the line capacitors and the filter. For the 40nF capacitor, I chose some 1% film parts at 630V and paralleled two of them for 40nF:
For the filter, two 10μF in series at 450V to make a 5μF at 900V. This part will probably get some heat shrink to strengthen the assembly. I chose this route because it was much cheaper than trying to find a part rated the appropriate voltage.
There are some resistors as well that seem out of tolerance, but those will need to wait. It’s not like this thing is going to be as accurate as a modern digital meter, but my concern was to prevent electrical problems.
The entire parts set to be replaced (save the 4μF):
1x 5μF filter capacitor assembly, electrolytic.
1x 40nF test capacitor assembly, film.
1x 0.01μF input blocking capacitor, film.
1x 1500pF capacitor for the eye, polystyrene.
2x 0.047μF across the line capacitors, safety film.
1x A1C neon bulb for the front panel.
Also, I am going to replace a poorly placed 1MΩ resistor across the eye tube, and perhaps the 1K and 500Ω resistors used in the test circuit (with the 500Ω just kind of hanging there in the air.) The latter two are both high-wattage parts (of unknown power) so a 10W part should be more than plenty on these.
That’s it for now - the next step is to put the parts in. That shouldn’t take long, but I’m also going to clean up some of the wiring as it’s in terrible shape. Stay tuned!
Next part of this series: https://wereboar.com … yzer-rebuild-part-1/
Previous part of this series: https://wereboar.com … some-notes-on-parts/
- 2024
- Dec
- 2
My 2025 Hamfest and Show List
As 2024 winds down, I find myself looking forward to the shows in 2025. I’m planning on going to most of the same ones, with perhaps a few new ones if time allows. I have quite a list this year, but I expect some of them will have to slip simply due to time constraints. One in particular, the 2025 Tri-State Radio Fest, may conflict with the TUSCO ARC show, so it’s a decision on what to attent.
As of the date of posting, not all shows have updated their dates for 2025. Check back soon, I will post actual dates as soon as I know about them. Links to pictures will be posted here as soon as I’m done with them, and I’ll do a year-end wrap up as well.
Johnstown Swappers Day and the Scott Antique Market aren’t really hamfests, but enough electrical and other goodies show up that it’s worth going if you’re in to general flea market type items. I’ve added The Cincinatti Hamfest to the list this year, and I may still try to get to the Van Wert show and Kalamazoo show, all depending on how things go. Dayton, of course, is a will-go no matter what, and we may have a table this year.
Sunday Creek Amateur Radio Federation Hamfest
Shade Community Center
2380 Old U.S. 33
Shade, OH 45776
January 19
8A-Noonish
Admission $6
http://www.arrl.org/hamfests/sunday-creek-amateur-radio-federation-hamfest-4
Event photos: https://wereboar.com … mfest-in-shade-ohio/
Cuyahoga Falls Amateur Radio Club Hamfest
Emidio & Sons Party Center
48 E. Bath Road
Cuyahoga Falls, OH 44221
April 5
8A - 1PM
Admission $8
https://sites.google.com/cfarc.org/cfarc/hamfest
Event photos: Coming soon.
TUSCO ARC Hamfest
Commercial Building at the Tuscarawas County Fairgrounds
295 South Tuscarawas Ave
Dover, OH 44622
Usually late April
8A - 1PM
https://www.w8zx.net/hamfest
Event photos: Coming soon.
Dayton Hamvention
Greene County Fair and Expo Center - The Whole Thing
210 Fairground Road
Xenia, OH 45385
May 16 17 18
Hours vary by day, opens at 9AM
https://hamvention.org
We might have a table at this one for 2025.
Event photos: Coming soon.
Breezeshooters Hamfest
Butler, PA
Butler Farm Show (Kind of a fairgrounds thing)
625 Evans City Rd
Butler, PA 16001
June 8
8A - 2PM
https://breezeshooters.org/ns/
Event photos: Coming soon.
Columbus (OH) Hamfest
Aladdin Shrine Center
1801 Gateway Cir
Grove City, OH 43123
August 2 (Not officially announced yet)
8A - 1PMish
https://aladdinshrine.org/hamfest/ (website 404 at time of posting)
Event photos: Coming soon.
Cincinatti Hamfest
Clermont County Fairgrounds
1000 Locust Street
Owensville, OH 45160
August 9
8A - 2P
https://cincinnatihamfest.org/
Event photos: Coming soon.
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: Coming soon.
Findlay Radio Club Hamfest
Hancock County Fairgrounds
1017 E. Sandusky St.
Findlay, Ohio 45839
September 7
8A - 1PM-ish
https://www.findlayradioclub.org/
Event photos: Coming soon.
The Cleveland Hamfest and Computer Show
Berea Fairgrounds, Eastland Entrance
160 Eastland Rd
Berea, OH 44107
September 28
8A - 12P
https://www.hac.org/
Event photos: Coming soon.
The Scioto Valley Amateur Radio Club Hamfest
Pike County Fairgrounds
311 Mill Street
Piketon, OH 45661
Date TBA
8A - 12P
https://www.arrl.org/hamfests/scioto-valley-amateur-radio-club-hamfest-2
Event photos: Coming soon
MARC Hamfest
Military Air Preservation Society Hanger (MAPS)
2620 International Parkway
Green, OH 44232
Date TBA
8A - 1P
http://w8np.net
Event photos: Coming soon
Fort Wayne Hamfest
Allen Country War Memorial Coliseum
4000 Parnell Ave
Fort Wayne, IN 46805
Usually the weekend before Thanksgiving
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
Usually Thanksgiving weekend
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
Usually the weekend before Christmas.
Hours vary by day, check before you go.
https://www.scottantiquemarket.com/
Event photos: Coming soon
Always check dates and times before going, and I’ll see you there!
Late additions (all of these may not be a go, but look interesting):
Central Pennsylvania Hamfest
Clearfield County Fair Grounds, Agriculture Building and grounds
5615 Park St
Clearfield, PA 16830
September 14
8A - 1P
https://clearfieldcountyarc.net/hamfest/
Event photos: Coming soon
Early Television Museum Fall Swap Meet
The Early Television Museum
5396 Franklin St
Hilliard, OH 43026
Usually early October
10A - 2P
https://www.earlytelevision.org/swapmeet.html
Event photos: Coming soon
NOARS Winter Hamfest
John Spitzer Conference Center
1005 North Abbe Road
Elyria, OH 44035
March 9
9A - 12P
Admission $10
https://www.noars.net/hamfests/winter-hamfest/
Event photos: Coming soon
NOARSfest 2025
John Spitzer Conference Center
1005 North Abbe Road
Elyria, OH 44035
July 19
9A - 12P
Admission $7
https://www.noars.net/hamfests/noarsfest/
Event photos: Coming soon
Tri-State Radio Fest 2025
Center Stage Banquet Hall
1495 Old Brodhead Road
Monaca, PA 15061
April 27
8:30 - 4:30P (Club auction at noon)
Admission $7
https://pittsburghantiqueradiosociety.org/events-and-dates/
Event Photos: Coming soon
The ARRL Ohio Section hamfest list can be found at this link.
- 2024
- Dec
- 1
Photos from the November 2024 Scott Antique Market.
This month’s show ended a few hour ago, and I made it out there on a very chilly, windy Saturday morning. For some reason, it opened later this year…some whispers about something that happened with the other show in Atlanta but I couldn’t pin it down. Doesn’t really matter, I guess, we entered about 8:45 and started wandering the not-quite-open aisles.
As usual, the place was packed with vendors and there was a lot to see. Not a whole lot I wanted to take home, but a radio that caught both my and my fellow show-goer’s eye decided to go home with me for a superb price. Check out that device, there will hopefully be a series of posts about making it sing again.
Here’s what we saw at the show:
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Next show is the weekend before Christmas. See you there!
- 2024
- Dec
- 1
The B&W Model 200 Signal Generator Part 3 - setting it aside for now.
In the last part, I determined that the tubes (save perhaps the 6×5) were not at fault in causing this device to act up. After I wrote that post, I sat down with it just a bit more and did some poking.
First thing was to put a good 10k power resistor in place of the one that rose to 160k when warm. No change in operation. Second was to give it a good look-over one more time.
I noticed that there was some goo coming out of the electrolytic in the oscillator section. That’s not good.
Ok, so that capacitor is probably bad. I measured the DC voltage on it.
There’s a really slow variation in the DC that matches the oscillator’s on-off cycle. I did some quick bypass with new caps, paralleling the presumed bad devices:
No change.
This thing has more problems than I originally assumed, and the lack of any information on the unit is hampering my ability to work with it.
For the time being, this goes back on the “needs work” shelf, as I already have a working generator and need to get some other devices fixed. If I can get to it before Hamvention, then I’ll take another look. Stay tuned!
Next part of this series: Coming sometime maybe.
Previous part of this series: https://wereboar.com … or-part-2-diagnosis/
- 2024
- Dec
- 1
An Unknown 2-dial TRF radio.
The Scott Antique Market happened this weekend, and much to our (and a lot of other people’s surprise!) it opened an hour later at 9AM. Remember what I said about checking hours? Well…guess what this stupid little pig didn’t do?
(Some update notes on this - it could be a regen unit as well, according to some. The little glass part marked “GLASTOR” may be a grid-leak resistor, aka GLASs resisTOR. And, there are no parts under the wooden plate. What you see is what you get!)
Anyway, there was some good stuff to see, but I didn’t really see anything I wanted to bring home until we were getting ready to head out. My show-going companion stopped by a big coffin set on a table. The guy had a price on it and I was going “That’s a good price for that piece.” I ended up buying a box of tubes he had beside it, but my buddy was stuck on the radio set itself. I looked, hmmm’d…do I have room for this thing. The guy said “If you want this, how about this other, lower price.” Buddy was just looking at me with puppy dog eyes saying get this dude. So I did.
It’s obviously a homebrew set. The empty hole doesn’t look like anything was ever in it.
Two tuning capacitors, a couple of rheostats, and an on-off switch adorn the front.
The cabinet itself is pretty good outside. A little scuff here and there and some paint splatter - but considering this thing is probably nearing 100 years old, it’s a solid external 7/10. Inside is very clean, and probably resembles the day it was built. There’s some cloth loss on the wiring, of course, but that’s acceptable and understandable. Some things will need to be tightened up - the escutcheon dials are loose - but nothing major.
Similarly, the rest of the case is in good condition. The varnish on the top is really the only bad spot on the unit.
As for the inside…it’s your standard TRF layout. Two tuning capacitors and a tuned inductor present themselves immediately. I’m not really that familiar with TRF sets, so I’m not going to go any further with that in trying to define what they all do. Four tubes, and two interstage Thordarson R200 transformers are really all that’s in this thing. I’m assuming there are some parts underneath the wood plate, but I have not dug that far into the unit.
I’m going to assume this needs +90, +22.5, +5, and +1.5, and that they went in the spot where the cables currently reside.
As for the tubes, all of them were present but wrapped in paper, so I don’t know where they go.
Tube compliment for this is 3x UX201A and 1UX200A. The 201’s are all RCA branded, and one has a Western Auto Supply price tag of $5.00 on it - that’s nearly $91 today! The final UX200A is unbranded on the base, but has a “Wizard” sticker on it. It’s also priced at $5.00 at Western Auto - so there’s nearly $400 in tubes in this thing!
The 200A dates this to at least 1926 and no earlier, as that device was introduced in May 1926. It’s possible the unit is older, but I can’t see someone discarding such an expensive tube just because a slightly better model was announced (although it’s possible.) Since superheterodyne was already a thing at the time, it’s probably not much newer than ‘26 as TRF was a rather poor (although easy) way of getting audio from the air.
The paper the tubes was wrapped in is a Columbus (Ohio) Dispatch from 1970, so the previous owner set it aside some 40 years after it was turned on. The paper itself is quite interesting - a story about how banks are cutting back on loans, a story about how federal payrolls are ballooning, and an ad for credit card fraud monitoring and restoration. You could almost change the date and reprint this thing!
Regardless, this was a great deal and I’m happy I brought it home. As stated earlier, TRF is really outside my knowledge range, so my next step is to grab a few early radio books that have TRF circuits in them. It’s quite likely that the original builder followed a schematic in a book or magazine, so finding something similar probably won’t be too difficult.
If you recognize the layout please let me know on Mastodon or LinkedIn, and stay tuned!
Next part of this series: https://wereboar.com … fying-things-inside/
- 2024
- Nov
- 27
The B&W Model 200 Signal Generator Part 2 - Diagnosis
As seen in the last part of this series, there’s definitely a problem in this unit preventing it from oscillating properly. It’s time to start digging in and seeing what’s what.
I picked up a new / tested good used set of tubes at the recent Fort Wayne Hamfest. I started with a baseline measurement to make sure everything was acting as before, and then started with the rectifier. The signal output was a big stronger, so the 6X5 is probably weak. Not a big deal, and probably expected.
Going around the rest, including the PTC resistor lightbulb, nothing changed save the signal was again a little stronger with a new 6SJ7 oscillator tube. Not enough to worry about, so all tubes were swapped back to the originals. The problem is in the components.
The device is mostly disc capacitors, and while they do go bad, it’s not often. Ignoring those for now, I decided to do a quick check to spot any obvious failures before powering and measuring voltages. First thing I checked was the big 10k 2W that I assume is a power supply divider.
160k and dropping. Odd…no capacitors here, and it finally settled down to 9.91k. That’s probably the smoking gun right there - the resistor is changing value as it gets hot and driving B+ down to a level where the unit can’t oscillate. Once the oscillator is off and the current is lower, the B+ increases just enough to oscillate - rinse and repeat. I need to check B+ to make sure, but this sure is suspicious.
With a reasonable guess secured, I did some spot checks around the oscillator. There’s a 33k across the 6SJ7 that has increased to 35.4k - a little out of tolerance but eh…there’s also a 200k flying off the tube, and it was quite high at 223k. Ok, that’s possibly a problem. I noticed two more of this type and checked those - way way out of tolerance. Everything else seemed to be close enough that I wasn’t concerned,
I wonder what made just those particular ones that bad?
There’s a couple of other things here that probably should go. That big white CDE El-Menco ripoff capacitor is a type that can be problematic. There’s also a dry electrolytic that’s checking fine but probably can go, and a black plastic capacitor that connects to the output control that needs to be replaced because they crack and gain moisture.
There are multiple supply electrolytics, and they all seem to be good. I’ll need to let the unit run a bit and see if they get warm, but if not then I’m not going to worry about them until something happens. I’m going to replace that nasty power cord as well, but that’s just a “always do it” thing for me.
With possible fixes identified, it’s time to set this unit aside until parts arrive. Stay tuned!
Next part of this series: https://wereboar.com … ng-it-aside-for-now/
Previous part of this series: https://wereboar.com … 00-signal-generator/
- 2024
- Nov
- 23
The B&W Model 200 Signal Generator
This is a device I picked up at the Dayton Hamvention earlier this year (2024.) It wasn’t much, but what caught my eye is that the thing is built like a brick shithouse. The big dial on the front is just wonderful in it’s smooth spinning. It’s missing a single output terminal cover, but that’s not a big deal.
This looks to be similar to most generators of the era, with a couple of extra tubes. I’m going to assume that since this has a balanced output, it’s using a phase inverter and final amp to drive the transformer output. Otherwise, it’s your standard oscillator and that old GE lamp as a PTC resistor, just like you’d find in a Heathkit or other type.
Tube compliment is:
6X5 as the rectifier
6SN7 as the final drive amp
6SN7 as a phase inverter
6SJ7 as the oscillator
GE3S6/5 lamp as a PTC resistor in the oscillator
(I assume)
The bottom is fairly clean. Some capacitors probably need to be replaced…
But a quick check says maybe no?
Output looks ok…
But about 3-4 minutes later the signal starts falling off, as in just fading to zero - and them coming back up. It just keeps doing this over and over, no matter what the output level or frequency is. I’m not sure what’s going on here, but the signal comes back up like the oscillator tube is dying.
I’m not sure what’s going on here, so I’ve picked up a new 6SJ7 and a couple of checked good 6SN7 to sub out and see if it’s one of the those. I have a used lamp laying around somewhere and I’ll check that as well. Other than that, I haven’t really investigated things much as data about this unit seems to be kind of scarce.
Stay tuned and we’ll see if this thing works!
Next part of this series: https://wereboar.com … or-part-2-diagnosis/
- 2024
- Nov
- 22
Pictures from the 2024 Fort Wayne Hamfest
The show this year was smaller than usual, occupying maybe 3/5 to 3/4 of the normal space, with a large section left empty. Prices at this show ranged from ok to stupid, which is kind of unusual as this show usually features pretty good values. There were a couple that simply were smoking crack and asking prices that would have been appropriate years ago when the equipment was newer.
I primarily went to get a bunch of tubes from Bob at hamtubes.com - he always has really good prices on tubes both rare and common, so that’s where I spent the bulk of my purchase money. A few other things came home with me, including a couple that will get featured here as soon as I can get to them.
There were still good things to see, and here they are:
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That’s it as far as hamfests for 2024 - the next two shows will be the Scott Antique Market events this coming (after Thanksgiving) weekend, and right before Christmas. I may combine those two into one post, depending on what I see.
See you there!
- 2024
- Nov
- 16
Pictures from the Ft. Wayne hamfest on the way!
The Fort Wayne hamfest happened today. The show was kind of mildy disappointing, with somewhat less vendors showing up this year - and some that were simply smoking crack when it came to prices. One in particular made eBay prices look low, and reminded me of the vendor that had those big stainless steel racks of test equipment at Hamvention with astronomical prices on them, rain or shine. I wish them luck in selling, but you’re going to be hard pressed to unload some of that stuff - especially when you can get new equivalents (from the same manufacturer!) for less.
Regardless, there was still some good stuff to see and take home. Stay tuned, pictures are on the way!
- 2024
- Nov
- 11
A Heathkit IG-72 Signal Generator - Wrapup, set-up, and final thoughts.
The device is working properly and has been buttoned up and put in it’s home on the bench. Here are my thoughts on how things went…
Thoughts
This unit was really the opposite of everything you expect from an old device. All of the passive components inside, like resistors and capacitors, were in good shape and don’t need replacing yet - although at some point it probably will require electrolytics. That’s for future me to decide.
This device really shows that you have to expect anything with an older device. Parts that don’t do anything other than hold a part can degrade and cause issues, especially when working with the higher voltages present in a vacuum tube device. I never would have though that a tube socket would fail like it did. Sure, they fail because the sockets themselves get weak, corroded, oxidized, etc. and make bad contact, but arcing across? That’s new to me.
I supposed it shouldn’t be unexpected, carbon tracking is a thing. The moral of this story is expect the unexpected. Especially when working with an 60 year old device that was built from a kit.
The complete timeline for this project
Acquisition at the hamfest: https://wereboar.com … o-club-hamfest-2024/
I should fix this thing: https://wereboar.com … 72-signal-generator/
Part 1 - Observations: https://wereboar.com … part-1-observations/
Part 2 - Suspicions: https://wereboar.com … r-part-2-suspicions/
Part 3 - Parts? Parts! https://wereboar.com … t-3-do-i-need-parts/
Part 4 - It’s…fixed? https://wereboar.com … no-need-for-repairs/
Part 5 - We’re not done yet! https://wereboar.com … 5-were-not-done-yet/
Part 6 - Back up and running: https://wereboar.com … back-up-and-running/
Part 7 - I think we’re done: https://wereboar.com … 7-i-think-were-done/
Intermission - The bad part: https://wereboar.com … athkit-ig-72-socket/
Intermission - That odd light bulb: https://wereboar.com … ther-test-equipment/
Wrapup - You’re reading it now.
Notes on calibrating this thing.
The calibration - more of set up - for this device in the manual was written for a time when you probably didn’t have a Hi-Z meter on your bench, but pretty much everything is these days. Instead of following the manual, I did this:
Equipment required:
Oscilloscope
Voltmeter that’s accurate at 1kHz
Leads and stuff
1: Set the frequency to 1kHz, attenuator switch to maximum, and set the output level to ~5VAC RMS using your meter. Ignore the meter on the face of the unit for now. Connect your scope and meter to monitor the output.
2: Let the device warm up. Get it nice and warm. I put a cardboard box over mine to get it toasty. I think this is also how I got it to arc continually so be careful here - don’t set it and forget it. Heat is going to cause marginal things to fail. Check on the device every once in a while during warm-up.
3: After a few hours, when the device is warm, check the sine wave output on your scope. Slowly adjust the oscillator output control (the potentiometer on the inside of the chassis closest to the transformer.) Adjust the sine wave until you just start to get one of the tips cut off, and then back off a decent amount so you have a good sine. Note: These have decent high output with fresh tubes, you can probably back off a lot here.
4: Let it set for a while. You may need to adjust this sine wave a couple of times.
5: When you’re happy with the sine wave, adjust the output level to 5.00VAC RMS with your meter. Using the meter level control on the chassis (it’s the other potentiometer inside the unit,) slowly adjust until the device’s meter so that it agrees with your meter. I use 5V because it’s dead center of the meter’s scale.
You should be able to assemble the device at this point and have a clean sine with a reasonably accurate meter. Note, however that this meter isn’t calibrated at every scale and frequency, so it’s a best guess at all times. The manual even warns about this, so if you need a precise level always let the unit warm up and adjust with an external device connected.
After everything was said and done, I had an accuracy of about 2% with the selected frequency. I think that’s pretty good for a device from the late 50s.
Why did I choose 1kHz? Primarily because this is going to be used for signal tracing. You can choose whatever frequency you think is best for your purposes.
One of the things I’m considering is trying calibration at 10VRMS. That is, set the level control to the maximum, and then back the oscillator control off until there’s 10VAC on the external meter, then adjust the internal meter to follow. This should keep the system well within the linear range. That should be possible since the output is constant before it appears on the attenuator’s input - but there’s always the chance that it won’t oscillate at some point (frequency) because it’s lower than what the circuit is expecting. It’s going to require experimentation to see.
That’s all with this device. It’s been on quite a bit as I’ve used it for testing devices that are in the “keep or sell” pile. If anything else happens to this, I’ll post about it here on wereboar.
Previous part of this series: https://wereboar.com … 7-i-think-were-done/