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Hey everyone, I was pointed in the direction of this group from the Tektronix subreddit.

Like the title says I don't have a formal background in EE or repairs, just some modest restorations of tape machines and other audio equipment. Apologies if I say something glaringly incorrect lol

So basically, I frequent a lot of e-waste recycling type places here in the Bay Area and today I spotted this vintage Tektronix unit next to the dumpster at one of these spots. I asked the cashier if I could take it instead, which apparently required a small transaction for their records. So $5 later I'm driving home with a TU-50 in the back seat

Now what I was expecting was that the internals would already have been more or less parted out already and that I'd reuse the chassis for a project, but when I took a look inside I was floored. The entire 70+ tube complement, original selenium rectifiers, coils, ect were untouched. The only thing missing seemingly was the accessory that plugs into the sine wave gen section, a single knob in square wave section that I replaced in the meantime, and also the cage that's supposed to hold up the fan has an issue I haven't looked at. I'm by no means set up or experienced enough to test complicated tube equipment like this so I can't report on that front unfortunately.

From what I've gathered, this was a low production one-stop shop for calibrating oscilloscopes that was only used internally by Tektronix during production in the 60s-70s? This one's no. 248

I really don't have the heart to tear down a well preserved piece of tech history like this. I mean even among the other pre-IC Tek equipment I've opened up, the point-to-point layout and construction is just artful. The row of 50 tubes upside down in the frequency division(?) section kept bringing to mind a flock of bats hanging from the ceiling of a cave or something similar

So then, what's the deal with these units? Are they well known among Tek fanatics? Are they still relevant for current day technicians who restore vintage scopes? Are there many collectors interested in test equipment like this that never had a public production run? I wouldn't even know where to start in terms of price, as there's seemingly no record of one being listed on ebay. Would it be better to hold on to for when I inevitably make the descent into building a proper amateur bench setup?

Very curious to hear from y'all, thanks!


Also, is there a good way to attach photos? My first post came back saying no attachments

Go to the photos section </g/TekScopes/photos> and create a folder called (e.g.) TU-50, and upload your pix there.

David

If you decide to sell it, I’m highly interested in it. I’ve been working on collecting Tektronix in house test equipment. It will have a good home.

On Tue, Mar 11, 2025 at 01:55 AM, ricky covell wrote:

Are they still relevant for current day technicians who restore vintage
scopes?

You are missing the attenuator probe... so you can't generate the various calibration voltages. (So, how will you use it?)
I've never seen one of those probes for sale.
The plug is a Cannon plug, I think.

I don't think they are relevant, except to individuals like Eric.
Maybe if you are really into 'tube type' boat anchor test gear.
AFAIK 75 year old 500 series scopes, don't need 75 year old test gear to calibrate.

I couldn't scrap it.
Cause it's good for holding down the basement floor, ... and taking up space... at least...until some villain re-scraps it.
If you don't want to do that... maybe give it to someone who values it... and won't destroy it.

Not sure how you would ship it though. (It's heavy, and bulky... going to cost a lot.)

--
Roy Thistle

Yeah, shame about the probe for sure. I had the same schematic up and it seems quite do-able, just a handful of resistors, a cap, and a 6110. I'm not familiar with the plug type so maybe that's another story. And yes, I'd rather keep it to heat my apartment than it wind up being picked apart by ebay detritivores.

Here's a few quick shots if anyone was curious: /g/TekScopes/album?id=301236
I'll have to carry it somewhere with better lighting this week haha


Re: Eric
You're more than welcome to send me a direct reply if you want to make an offer. I'll be thinking on it for a couple more days, but I'll keep a note and get back to you if I'd like to pass it on to someone. Appreciate it

ricky covell
<hypomnnqn@...?subject=Re:%20Salvage%20yard%20rescue%3A%20Tektronix%20TU-50.%20Some%20questions%20from%20a%20non-tech>
wrote:
Date: Tue, 11 Mar 2025 21:29:54 PDT

(The leveler) seems quite do-able, just a handful of resistors, a cap, and
a 6110.
You do not need the 6110 tube. While not totally unobtanium it may be
easier to replicate the sine wave leveler with the 190B leveler which uses
a pair of 1N97A germanium diodes and a different resistor network. It will
work equally well as the tube version used with the 190A. The TU-50 is a
combination of three production instruments housed in one large cabinet.
The three instruments are a 190 constant amplitude signal generator, a 180
time-mark generator, and a 105 square wave generator. Schematics available
on Tekwiki. - Ferrous

I prefer to use vintage equipment to calibrate my oscilloscopes, mainly because I enjoy the challenge.

I just hate to see these golden age of electronics jewels going to the scrap and being destroyed. And at this time I have room for the larger 500 series stuff.

A TU-50 has been a want for quite a while now. I don’t need it, but I’d like a nice one to preserve.
So I sent you a PM Ricky.

On Wed, Mar 12, 2025 at 09:36 PM, Eric Boyle wrote:

I just hate to see these golden age of electronics jewels going to the scrap
and being destroyed.

Well... I hope you can get it.
You'll have to find the head/probe... or construct it..not hard; but, tedious.
IMO... it won't satisfy someone who is new/newer to electronics: even though it is a Tek made calibration unit... it doesn't come close to even reasonably cheap modern gear!
... it's big, heavy, power hungry, high voltage gear, with lots of tubes. (The kind of stuff we like... but the shine wears off quickly... if you're not one of us.)
IME... for the non-bitten... it goes to holding down the basement floor, until the better half orders it to be ditched.
So I hope you get it.

--
Roy Thistle

On Wed, Mar 12, 2025 at 10:15 AM, Ferrous Steinka wrote:

(The leveler) seems quite do-able, just a handful of resistors, a cap, and
a 6110.

True.
But, it's not the same is it.
Here you are... pretending... and fantasizing... about being back in the day... of vacuum tubes and zinc plating...
when what you are holding in your hand isn't authentic; but it connected to something that is.
I suppose... more dreaming... or more beer required.

--
Roy Thistle

I hope I can too, it’ll give me a reason to set up a dedicated 500 series calibration bench, something I’ve been meaning to do.

Right now I’m sitting on 17 1950’s/1960’s scopes.

556
R556
(2) 547
545
310A
585
(3) 532, one working
(4) 575 Mod 122C
565
561A
564B
(2) Type 130 LC meters
Engineering Power Supply
Type 180 Time Mark Generator

Plus a 7904 and a bunch of TM500/5000 stuff.

Had to list them out to count them!