Let’s play Wheel… Of… DUMPSHIT!!!

I just received two new 4CX250B / 7203 tubes for one of our transmitters, an old Continental Electronics with the tube intermediate power amplifier (IPA).

I’m already wondering just how they’re going to fail. Not IF they’re going to fail, more like, how, and how much collateral damage will occur.

The sad story: These tubes used to be produced by Eimac and were perfectly fine. At some point, Eimac got sucked into some giant ugly conglomerate that consolidated their tube manufacturing and made some awful changes, then hacked and slashed at their product line. That effectively led to a quality fade then discontinuation of the tubes.

I’ve been pretty much informed that the way to get GOOD 4CX250B tubes is to either go back to 1981 and stockpile them, or find someone who has them sitting around from back then and hope that they’re not gassy or badly manufactured tubes from Eimac’s Salt Lake City facility.

So now, what do you get when you try to buy a 4CX250B?

….this. this is the dumpshit you get. alibaba.com’s finest, I’m sure.

FEELING LUCKY?

These are “National Electronics” marketed by Richardson Electronics. Richardson’s website only mentions the Eimac tubes that they were a dealer for, and when these were ordered, there was a week’s delay in getting them shipped. National Electronics used to be a perfectly legitimate tube dealer or manufacturer – I think they went with contract manufacturing back in the day, as you’d see a really wide variety of their tubes out there, everywhere from receiving valves to power tubes and even indicators like Nixie tubes. Now, my best guess is it’s just a shell being kicked around via brand name necrophilia.

I don’t know if these even work at all, and won’t until I can get to a mile-high transmitter site whose means of access are currently buried in snow and ice.

So, for now, let me compare them to a new old stock Eimac tube. This is a 3CX800A7, a different tube entirely, but using the same sort of package and plate structure.

Eimac tube on left.

Immediately the bright silver plate finish becomes apparent, along with a far different cooling structure. The fins are brazed or soldered to the plate. This is important as the outside of the plate cooler is usually used as the electrical connection via a clamp around the tube. You do not want a bad connection in there.

And now, the Richardson/Alibaba Special – they just… lovingly shoved it down in there with a press and called it a day.

No signs of soldering or brazing are visible.

All in all, it looks like it was just smashed together using the same tooling one would use to make cheap and nasty refrigerator coils.

Now, about that gray mystery metal….

I looked at the socket pins and saw no marks on them at all, just a uniform gray coating of… whatever.

On the Eimac? There are marks in the silver plating from where the tube was put in a socket for factory testing.

Did they even——??? Is there any factory testing??

How’d this Oddish get in my transmitter?

what the fuck is any of this, i need a nice adult beverage

So yeah— I’m NOT convinced these are even going to work, but I guess that’s what I can get now. Thanks, Crapitalism!

Annoyance

Sometimes you just wonder “what was ANY OF THAT?”… yeah.

I dunno, I got pretty frustrated trying to get some old equipment up and running again, and then discovered that my wonderful old Tektronix 2232 oscilloscope started also suffering Capacititis or something. First I came in this morning and was like, what on earth even happened to the bench— oh wait, an amazing struggle with a QEI 675…

Then the scope went blank with a weird whining sound that suggests ye olde crapacitors have failed… I had previously had an issue with the screen getting garbled on this, and percussive maintenance brought it back, but not this time. I went to open it up and look around inside and the blue painted aluminum shell got jammed. I even had a coworker tug on one end while I tugged on the other, it was kind of amusing but pointless. I finally got it loose with silicone spray and slowly wiggling it off. What a mess.

Intel Inside

The usual fancy custom silicon that’ll effectively e-waste the whole scope if any of it gets damaged. Luckily, on this scope, they did NOT use a whole horrible death forest of tantalum capacitors.

Guess it’s all just telling me to slow down for a day and get some smaller things done…

Deep thoughts

Why do we call it plate voltage and not bowl voltage? The plate (anode) of the tube is that radiator-equipped bowl over the top. It’s not a flat plate by any stretch of the imagination.

Plus, saying “bowl on” is more satisfying than “plate on”.

BRAWNDO! It’s got electrolytes!!

Unknown energy drink spilled in very unobtainable telephone hybrid control surface.

The small is like that of old Jolly Ranchers and BRIMSTONE.

Welcome to Monday Night Rehabilitation. Chances of this thing’s survival are probably about 60%. Chances of the survival of whoever spilled their drink down this and said nothing about it until it hardened into foul lacquer—-???

Linguini Mountain, Part II

This post is to be assumed to be to the tune of She Wants Revenge – Out of Control. available on YouTube here. So I was up here again and was asked to check the generator and fuel level. Fuel was fine, generator started, amazingly, with only minor reluctance, and immediately filled the shack with exhaust, so I left the vent fan on and walked away for a while, came back, ran in holding my breath, shut it down, and left for a while more. It urinated on the floor… Sure looks like one of the CrapsackWorld props from Idiocracy, doesn’t it? But then I heard a buzzing that didn’t sound right after the generator was shut down and traced it to a pair of relays oscillating. I unplugged the power supply to them and a nice fireworks show of good ol’ arcy sparky happened for a moment, ending with a power strip breaker tripping. Beautiful. I then got to work……

None of this was functional anymore. Especially not after the fireworks show…. Now I’ve just gotta rewire the remote to one of the transmitters to eliminate a final layer of relay bodge and I can start over with better control. How do I come to inherit these things??!! Sadly, off air time may be required. What a thing to greet my operations manager with when he returns from vacation! “Welcome back, I need to nuke your stations!” Actually he’s a really awesome guy and he won’t be mad at all.

sudo init 6

I had to reboot my Subaru Forester tonight. It threw literally every possible error message following coming up with the traction control, hill assist, and ABS warning lights on.

The fuse to reboot it is a 20 amp at the front center of the under hood fuse box labeled “Back Up” in the legend.

So here’s how you reboot a car. Note that some vehicles have this fuse labelled as dome light.

On certain navigation/audio systems you will need an anti theft code to reactivate them after this.

Either way, pull it, wait 30 sec, and reinsert. Be careful not to touch any hot parts under the hood if the car has just been running. A fuse puller is likely provided in the box, but if not, many replacement fuse kits come with one, or you can use small pliers to grab it.

After pulling the fuse, waiting at least 30 seconds and reinserting it, don’t be surprised if you get an errant horn honk, beeps, or clicks. Aftermarket alarms may start blasting and need to be turned back off with the remote.

Wait another minute or so, then restart the car. Check that the stereo comes on (or asks for the code…) to be sure its anti theft logic has cleared out. You will need to reset the clock and other settings may be gone as well.

In addition, it may drive differently at first as adaptive data has been reset.

Congratulations! You now know how to clear an automotive BSOD.

Now, if people would only stop arguing with me and trying to convince me that piercing guns are actually of acceptable design… Why has this happened like six times in the last week??!!

This dumpshit is getting out of hand

Three different variants of Chinese fake ULN2803 chips available on Amazon and eBay. No genuine chips are available on either.

Bonus: “18 pin” DIP socket from Chinese mega-dumpshit-flooder uxcell, who deserve their very own angry shitpost. Hey at least they didn’t send me mis-molded automotive trim clips instead of LED mounting bezels OH WAIT THEY DID

I’ve used up all my actually genuine ULN2803s so I don’t have one for comparison, sorry. 🙁

PTEK combiner. Shibe version.

I have no words. This thing is so wack i didn’t even recognize I was looking at a classic Wilkinson combiner implemented using cast off garbage. I’ll let the shibes speak.

The exciter power divider. This seems to depend on the external jumpers

Shitposting Electromagnetically

This miniscule coax from Pasternack carries 500 watts over its… 26-28 awg center conductor??!!

Also yes I know, time to repaint

Dot matrix printer ribbon fun (TFT EAS 911 and others)

(We’re saved! The original Epson ERC-09B ribbons appear to be available again via Amazon.)

This post has been technically deemed a shitpost because WD-40 is involved. Also something that looks like Comic Sans.

Shitposting loudly

This is the tiny printer ribbon used on the TFT EAS 911 and many other devices using a small dot matrix printer mechanism. This particular unit is hilarious, it’s less than half an inch thick and appears to contain a one pixel printhead!! The way it works, noisily, is that the printhead cycles back and forth on a bihelical gear as the paper feeds one pixel height at a time. It takes like a minute and a half for the log output from a RWT (Required Weekly Test) to creep noisily out of there.

So the ribbon was fading away on this one and i opened a fresh… new… old stock (uh oh) box of ribbons. They were all dried up in the box.

The ribbon feed knob wouldn’t move the cloth ribbon at all. Curious, I carefully pried the top off.

Larger ribbons as used in some dot matrix printers like the Citizen 200GX/GSX140 models had a big boxy space filled with lots of ribbon that kinda folded up in there and flowed to the other end. Smaller ribbons that went on the carriage (Okidata, IBM, and Apple printers were like this) usually contained a foam roller that stored ink and transferred it to the ribbon. They were easy to re-ink; I always just applied stamp pad ink and WD-40 with good results. The light mineral oil from the WD-40 helped the ink transfer and lubricated the print head pins.

This just has a small band and two foam rollers. The ink was there but dried, so I just applied WD-40 to the ribbon and both rollers.

Success.

I tried this on a second one in the box but it seemed its feed roller had separated – the plastic core spun free in the foam sleeve. That seems to be the game over point on these things, it can’t feed anymore once that happens.

I’m not sure if these are still made fresh somewhere. I’ll have to check later. For now, Fun With Subcarrier Audio is on the agenda.

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