- 2024
- Mar
- 24
An Eico 145 Signal Tracer - Part 1
( Read the first part of this series here: https://wereboar.com … ignal-tracer-part-0/ )
I’ve decided to give this Eico 145 tracer a new lease on life and put it into service on my test bench - but to do so will require replacing the bad parts. Which ones? Pretty much all of the passives aren’t any good at this point. The device itself isn’t the cleanest example of it’s kind, with lots of battle scars. Paint and rust decorate the front panel and chassis, and input jacks have been added to the front.
The signs of use are the reasons I’m putting this on the bench. It’s already seen it’s share of use and won’t mind some more.
The chassis has the expected rust and age. That happens, there are no rust outs or severe damage here so I’m not worried about it.
The unit itself has some interesting things about it. There’s supposed to be a 10uF capacitor across this big 470Ω resistor. This is the cathode resistor for the audio output tube, and the capacitor is there to improve audio fidelity. I’m not sure if that was omitted because it’s not going to do much when most of your signal is 1Khz, or if it was damaged and removed at some point. The capacitor visible at the bottom is also an oddity, being an 800V part on the grid of a 6SJ7 - there’s nowhere near 800V present in this unit, and nowhere near B+ on this grid. Why this is such a high voltage part is a mystery but is probably just “That’s what I had on hand.”
The audio output transformer is somewhat of a mystery as well. I can’t tell if it’s been replaced or was just misdrilled. It doesn’t match the holes in the chassis, so I need to track down the part number and see what it was originally meant for.
Tape and wire and WTF indicate this thing had multiple repairs over the years. All of that needs to go.
Some more user friendly parts will be added to clean up the device and make it more accessible.
There are some other considerations to take into account. This device was originally meant to be ran on 110VAC - unlike our modern line voltages of 120 to 125VAC. This means B+ is hot, and filament voltage is well over 7VAC - in this case I measured 7.11VAC! That’s too hot, and will burn out the tubes in short order. Another restoration suggested a couple of parallel opposing diodes to drop the voltage in the filament line down, so there will probably be a couple 100V 2A diodes in this thing’s future. It was also suggested that the 6K6 is being run hot, so increasing the cathode resistor’s value (the large 470) would bring the power on the plate of this tube down.
Since most of the parts are being replaced, the analysis is just to make sure there aren’t any major problems that would stop the show - and I don’t see any. The next step is to create a new parts list from the schematic and get things ordered.
I’ll see you in part two with that schematic and a parts list.
Next part of this series: https://wereboar.com … ignal-tracer-part-2/
Previous part of this series: https://wereboar.com … ignal-tracer-part-0/
- 2024
- Mar
- 24
Pictures from the Scott Antique Market
The Scott Antique Market has closed for the season in Columbus, with the next show happening in November. There weren’t enough things to make a post for each of the past few months, so I’ve consolidated everything from this year into this one post.
The normal assortment of radios, televisions, and other electrical oddities showed up, with a number of just interesting or other neat things.
I did pick up one item that will be the subject of it’s own post, but until then - here are all of the things I found interesting from the last three shows.
- 2024
- Mar
- 17
An Eico 145 Signal Tracer - Part 0
I sat down with an Eico 145 Signal tracer this weekend, evaluating what it would need to put it back into daily service. The answer? Pretty much everything. Leaky wax capacitors, carbon comp resistors that are 50% off of their marked value, and a few “doesn’t appear to ever have been installed” parts complete the list of this thing’s issues. It’s amazing that it’s still working, but I would bet that continued operation would destroy the tubes in short order.
The large 470Ω resistor in the foreground was of interest. A quick shout out to a friend confirmed that this was a 2W part, not a high-voltage device. This makes sense, as the resistor could potentially dissipate 600mW at maximum plate current. It’s also interesting because there’s supposed to be a 10uF bypass capacitor across that part, but it looks like it was never installed!
Right under that, of course, is the across the line capacitor. That ’splodey boi gets replaced first.
A quick trip to mouser for components is in my future.
Next part of this series: https://wereboar.com … ignal-tracer-part-1/
Previous part of this series: https://wereboar.com … o-145-signal-tracer/
- 2024
- Mar
- 12
An unusual 115VAC demand meter.
I picked this unusual device up from an antique store in rural Pennsylvania, near where the groundhog works one day a year. It’s a fairly large place and prices vary, but it’s worth a couple hours of your time if you’re into that sort of thing, see the link below.
(The place seems to only have a facebook presence, and I’m not going to post one of those dirty links here - but here is the local chamber’s page for Yoder’s Antique Mall in Punxsutawney: https://punxsutawney … 73c05f142052452104c6.)
It’s a toolbox! Yeah, right on! Well…no, unless you’re interested in old toolboxes. It’s a fairly nice example of something from when Sears used to make things worth more than the metal it was stamped from. It’s what’s inside that I was interested in.
It’s a demand meter! Yeah, right on! Well…yes, but there’s something unusual about this one. It’s a 2-wire, 115VAC unit. While this is similar to what you would have on your house (or would have had before the electronic switchover,) those are usually wired for 230VAC instead.
This one appears to have been meant for sub-branch metering at some point, as evidenced by the easy-to-remove wiring compartment at the bottom of the meter’s housing. Whomever had this before me took advantage of that in that they wired a plug and outlet in line with the device - perhaps as a jobsite meter to pay the site owner for power consumed? Not really sure here save that all of the cable is pretty stiff and in need of replacement if it was going to be used.
Overall age of the device is in question as well - it looks to be 1930s, but Westinghouse probably made these things for decades. I suppose I could try and track it down by serial number, but who knows if those records still exist?
I tried it out by hooking it to a kitchen appliance with a heating element. It works as expected.
I’d like to get it out of it’s silicone covered metal box for a good cleaning, but that’s a project for another day.
- 2024
- Feb
- 11
I guess making a complaint does work.
I recently wrote about my experience with a large enterprise that still had an email system that didn’t meet changes made in 2014. I wrote an email to their DMARC reporting addresses explaining the situation - those bounced with full mailboxes. I wrote an email to Contact Us and got boilerplate back. I didn’t expect anything else.
I poked at their system one last time with mxtoolbox, and it looks like they actually did fix it. I’m not sure when they did so, as of Friday they were still being sent to quarantine by my provider, so it must have been after hours or something - perhaps my email system was still prejudiced because records hadn’t propagated yet.
Who knows. But I guess that goes to show, sometimes making a complaint does work. It just amazes me it took 10 years and someone not getting a single email to fix it.
- 2024
- Feb
- 10
Magic Eye Tube kits from China
I picked up a couple of small kits from everyone’s favorite Chinese junk store, Aliexpress:
They appear to be the same base kit, except that one has an EM80 cat’s eye style tube, and one has an EM84 style side-looking tube. There was also a 200V power supply included with one of them, but I’m not sure which one it was at this point.
There are absolutely no instructions to speak of, but the boards seem to be well labeled. It shouldn’t be too much trouble to get these together, assuming all the parts are correct.
I’m planning on assembling these in a few months (as time allows,) so check back to see if they’re done and my thoughts on assembly and operation.
- 2024
- Feb
- 4
Multiple email SPF records? Yeah, go away kid, we don’t care.
I’ve written about email security and having the proper records set in the past, but last week I ran across probably one of the most interesting (and really bad) ones to date.
I use an email service that I pay for, simply because I like having my own domain name - as you can probably tell by the links that pepper my posts, and the fact that you’re reading this on Wereboar.
Sunday, I (was supposed to have!) received an email from a large corporation that contained information that I paid for. Didn’t get it, so I logged in to my email maintenance console - and there they were.
They were quarantined in a way I’d never seen before. All text and links were struck out. Nothing could be clicked. You could move them around, but they would never pass into visibility in any IMAP folder. The only thing I could do is delete them in the maintenance console. The system would not release them - they were so suspicious that they just wouldn’t. Period.
The first thing I do is check the company in question’s email records using mxtoolbox - and there it is. Two SPF records. While this was acceptable at one point, a change to the way email worked - IN 2014! - made having multiple records of this type a red flag, and any email system worth it’s salt will, at minimum, dump these into spam.
SPF is a text record set in an email service that tells the email server who is allowed to send mail. You’re allowed one. Having more than one means that someone else could have set one without your knowledge - and that leads to all kind of interesting scenarios, the least of which is lots of spam being relayed through your email server.
The change that allowed only one SPF record was made in 2014. That means this large multi-national corporation has had 10 years to make this simple fix to their email system.
My email service didn’t put these in spam, it simply said “Nope, not going to let you have these, they’re suspicious beyond compare.” The fact that it’s a world-wide operating company that many use on a daily basis is even worse. They have the time and resources to take 10 minutes and set their email server up properly. I made a complaint. Will they change it?
No. They literally don’t care. Send an email to the ones set in their other security record (DMARC) and it comes back “mailbox full.” No one is even looking at issues.
So, did I get my information? Yes. I keep a couple of old Gmail addresses for whatever reason - nostalgia I guess. Gmail used to be the gold standard for consumer email service, but now it’s the library book of email services. It accepted the malformed records without complaint, which it absolutely should not have done.
What do you need to take away from this? As email becomes more and more weaponized, you’re going to have more systems rejecting your email. Fix your $&#&$! crap. If you don’t know how, hire someone to do it for you.
If you don’t, there’s going to be a time when you can’t get your email through. And that’s going to be purely your fault.
Don’t wait. Fix it. Now.
- 2024
- Jan
- 23
All of the documents currently in wereboar’s archive - Part II.
I’ve added a few more documents to the Wereboar archive on both the previous entry, as well as this (new) entry. More will be added as I gain more manuals for equipment featured here. These are hosted by my webhost’s cloud storage system, OXDrive.
Original document archive post:
https://wereboar.com … n-wereboars-archive/
The Knight KG-690 and 83Y135 Signal Tracer (Same chassis, different cabinet):
https://privateemail … 11cf/1/8/NDY/NDYvMTU
Radio Shack “Science Fair” 28-177 Crystal Radio Kit Owner and Assembly Manual: https://privateemail … 8376/1/8/NDY/NDYvMTY
All of the documents currently stored in the wereboar archive, as of April 8th 2024 (165MB zipfile) - anything below this is not in this archive:
https://www.dropbox. … w2v18oho5tib9vu&dl=0
The EICO Model 540 Readi-Tester:
https://privateemail … ed43/1/8/NDY/NDYvMTc
- 2024
- Jan
- 21
An IMD-202-2 for parts…but let’s take a quick look anyway!
SO…here’s another one of these piece of crap meters. Why? This one was cheap, and was purchased non-working - primarily for parts, as in the NIXIE tubes. ZM1000 tubes aren’t exactly common these days, so having a few spares laying around seems to be a good idea.
I decided to at least take a look inside to see what’s broken. It doesn’t power up because the fuse is blown. That never bodes well, so I jumpered the fuse temporarily and turned it on quickly.
Yep, it’s got some problems. All segments of the tubes are lit, and the tab on the +5 regulator transistor got pretty warm being on for 5 seconds. Turned it on again to get some quick voltage measurements:
+5V Output (Emitter) = +0.8V
+6V (Base) = +2.6V
Measuring the resistance to ground:
E = 2.8 Ohms.
That’s not good.
A good unit measures (to ground):
E = 1.4MOhms.
+5 primarily powers chips, so I pulled all the ICs to start. Things changed, but not necessarily completely back to normal.
Good unit:
E = 1.4M
B = > 8.5k (charging)
C = Open
Bad unit:
E = 2.5k
B = 1.9k
C = Open
I started putting chips back in, the very first one I replaced (IC5) took the Emitter of the regulator transistor down to 3 Ohms. So that chip is bad.
However, there’s something else wrong. With all the chips gone, the +5 load should be negligible. I did a quick scrape on the transistors to see if one was shorted but didn’t find anything obvious. That leaves old capacitors that could be leaky. This thing is full of Tantalum drops and cheap-ass film caps, any one of those could be partially shorted and there’s no real way to know except to start lifting parts.
Since this is just a parts unit, and the tubes and driver ICs appear good, I think it’s just going in the parts bin as intended. Maybe if I have some snowy Saturday, I’ll pull it out and start lifting parts to see what’s going on. But for now - parts is parts, and parts is what it is.
- 2024
- Jan
- 20
Magic Eyes - glowing green magic from the vacuum tube era.
One of the most interesting and accessible pieces of tech that came out of the tube era is the Magic Eye. A phosphor cup (or target) is illuminated with an electron beam, and a grid allows or blocks that electron beam to “open” the eye. It’s a device that can indicate changes at the speed of the phosphors used, and it found it’s way into all kinds of devices - radios as tuning meters, signal tracers as signal indicators, capacitance checkers as a quality meter - anywhere a fast visual change needed to be shown to the user.
These two signal tracers, one branded Knight, the other Eico, have eye tubes as their wattmeter and signal indicators. The Eico’s eye is so bright it overloads the camera, while the Knight’s eye shows much more use in it’s dimness.
While eyes fell out of favor as meters, VFDs, and other electronic indicators came into their own, they still remain one of the most striking devices in mid-century electronics.
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