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On Thu, Dec 9, 2021 at 02:31 AM, Dave Peterson wrote:

What's the difference between this and a Standardizer, 011-068? I see a
listing for a 47pF Standardizer with 011-068, but I'm not finding that on
TekWiki. Roses by different names?

Hi Dave,
This explains it all:


Raymond

I'm tuning up my 5100 scopes and plug-ins. I need a 47pF normalizer: 067-0541-00.



What's the difference between this and a Standardizer, 011-068? I see a listing for a 47pF Standardizer with 011-068, but I'm not finding that on TekWiki. Roses by different names?

Dave

Given that you are going to do a minimalist debugging session.? I have a few suggestions, and others will modify them as needed. Starting from the basics:

1) The + 65 volt line is used as a reference voltage for the +5 volt line.? Just in general, if the +65 is not right, the +5 is not likely to be.

2) all of the supplies are linear.? While they do not have to have loads to operate, they might be happier with loads.

3) disconnect as much as you can from the power supply

4) measure the voltages.? If there's any short on another board, it shouldn't affect the power supply.? If there's still no 5 volts (and if the other PS voltages are OK), then check the parts on the power supply part of the board that makes the +5 volts.? The TEK WIKI has several copies of the service manual, make sure that you get the one that matches the serial number of your scope, it will make a difference.

5) if the power supplies are ok, then plug in board assemblies one at a time.? I'd suggest (in no particular order), horizontal amplifier, vertical amplifier, sweep, and then miscellaneous.? if at ANY time you get a very bright spot on the CRT (the HV will be plugged in), then make absolutely sure that the intensity control is turned down.? You don't need a spot on the CRT for this, and you will possibly damage the CRT.

If you don't have a current limited supply (typically set for 5 volts and about 100 ma.), then put a 50 ohm 2W resistor in series with the 5 volt lead and run the board from that.

For each capacitor, measure the voltage across it.? Assume that the input of the board goes three places (with capacitors across each "branch".

Using the schematic, measure the voltage across each capacitor. If a branch has no short, then the voltage across each capacitor would be roughly the same.

For a branch that has a short halfway down, you'd expect to see decreasing voltages down to the shorted part, and then roughly the same voltages from then to the end of the string.? This procedure will find the furthest one in the chain first.? Having more than one shorted capacitor in a branch will make things more difficult.? The lower the range you use to find the part, the better this will work.? Measure across the capacitor in question, as close to the leads as possible.

One of the more likely suspects would be a tantalum capacitor that looks like a piece of candy.? That type fails frequently.

Your 5 volt supply will work well when set to 100 ma.? I think you can try this on a per-board basis.? Depending on the board, you may not need the other voltages, but that can vary per board and I'd welcome opinions on which.

Harvey

Hello all,

The latest revision I can find is APR90. Anyone have any later revisions? Thank you so much!

Very Respectfully,
J G

Apologies for the delayed response however I needed to resolve some things.

I have no access to a high resolution DMM

The only PSU I had, is an obscure Brazilian Sincler which kept (and keeps) blowing whenever it exceeds 500mA.

Due to Brazilian-level funds, I went out across to the other side of the city and bought a cheap, used, Chinese PSU only to discover it to be blown once I got indoors. After returning the next day to exchange it (and unable to test it) I was once again given a dud (for Brazil, think Nigeria). Anyway, last night it was disassembled and after finding a burnt resistor and swollen cap, the adjacent chips were replaced and finally, I have some form of working PSU.

Having said that, it has made no difference, for as soon as it is connected across the 5v rail of the scope, the PSU voltage drops to zero and a loud alarm sounds.

As for the dimtester, I also tried that but am not really sure what I should be looking for, as other than the lightbulb glowing bright, not a lot else seems to happen. No hot components etc.

Hello Walter
This is very interesting, just today I received my latest purchase, which included one of these units and I was wondering what could I do with it.
Well, your discovery makes it more valuable than free!

Thank you

Jose Orgnero VE7LBI

We break apart DataCheck multi-scope strips to salvage the hard to find euro D7-200/201GH CRTs, It may seem like a terrible sin, but trust me, it has a lofty purpose. In the most recent one, I found something quite extraordinary. There was a bank of tiny screwdriver adjustments under a cover at the front, leading to a huge number of trimpots at the very rear of the module. This was accomplished by a nifty fiberglass rod with an amazing end collar that neatly captured the screwdriver adjustment on the trimpots.

Now, you ask yourself, well, so what? The beauty of this item is that you wind up with a foot long insulated fiberglass pot/capacitor adjustment tool that has no metal in it at all. These look like they might be very useful for those temperamental trimming adjustments that every good piece of gear seems to have. they are so long, you could cut them in half, and easily grind a screwdriver end on the new piece, and now have two insulated tools. I know the topic of insulated screwdrivers came up recently, which is what got me thinking about these.

Anyway, they seem useful (even just as replacement shafts for Tek pots!) , and incredibly well made, so I am happy to send some to anybody that can use them, either full length or cut in half (cut allows a much smaller bag). A padded bag cost about $6-7 to send almost anywhere, so if you can cover the shipping cost, I can send some your way. I will post pics of them up on the stuff page once I have them shot.

All the best,
walter (walter2 -at- sphere.bc.ca)
sphere research corp.

Presumably because someone managed to knock the slope/level knobs askew, and bent the crap out of the concentric shafts?

I added some pictures to your album to illustrate. I've repaired these before. Contact me off-list and I'll see if I can talk you through what I did. Takes 2 parts finesse, 1 part brute force.

Found a pic and added it to your album.

I tried annotating it, but my photo editing tools suck.

Looking at the picture, it slides left behind the A8 (trigger) board with its slot held on the A9 (bottom) board. The nut for the lower power switch screw goes in the hex cutout in the part - faces away from the A8 board.

You'll figure it out. :)

Dave

That is part of the power switch assembly. It holds the nut to the lower screw mounting the power switch. I'm not seeing it in the exploded parts diagram. Let me see if I have a picture.

It is intended to be captured between the A9 board and the A8 board.

Dave

I opened my 465 case and a part fell out, I put in the photo section under, “465 part?” Can anyone tell me where this goes?

Thanks, Andrew

Hello all I’m in need of a Slope Level Potentiometer / switch for a 465 Scope

Andrew

On Wed, Dec 8, 2021 at 10:36 PM, Albert Otten wrote:

A funny coincidence and somewhat of topic. At the crystal housing I saw the
name Bulova. Never heard of and sounded Eastern-European for me. Just a few
hours later I saw a Dutch TV program like the The Antiques Roadshow on BBC. To
my surprise one of the discussed objects was a watch made by ... Bulova, model
Accutron, from the USA. Interesting internals with tuning fork, also shown at
Wikipedia. The driving transistor for the magnet coils were produced by
Philips here.

Hi Albert,
You probably remember that I am (actually: used to be) a watch collector, so you won't be surprised that I am familiar with Bulova. I still own one of their Accutron wristwatches. Bulova used to be in high esteem and at one time, competed only with Omega for supplying a moon watch in the Apollo age. Like Omega and Patek-Philippe (HP 5061A Caesium-beam clock!), Bulova made devices for scientific purposes as well.
Their tuning fork resonates at 360Hz, which results in an audible buzzing. They are quite position-dependent, not a nice property for a wristwatch.
Unfortunately, they run on a once ubiquitous (Hg) battery that is no longer in production. Alternatives probably exist but I never looked for them.
They were a nice bridge between ticking escapement-driven mechanical watches and the later quartz watches.

Raymond

A funny coincidence and somewhat of topic. At the crystal housing I saw the name Bulova. Never heard of and sounded Eastern-European for me. Just a few hours later I saw a Dutch TV program like the The Antiques Roadshow on BBC. To my surprise one of the discussed objects was a watch made by ... Bulova, model Accutron, from the USA. Interesting internals with tuning fork, also shown at Wikipedia. The driving transistor for the magnet coils were produced by Philips here.

On Tue, Dec 7, 2021 at 08:53 PM, n4buq wrote:

By the way, I wonder if someone could clarify one of the steps in Chapter 6.
Paragraph 4.c. states:
"Adjust L18 (Fig. 6-7) midway between the two signal maximum amplitude points."
Does that mean that as the slug is moved through the coil, one should see two
maximums and then set the the slug midway between those positions? I ask
because I don't see two maximum values and, instead, the waveform changes
somewhat as I move the slug but that's a bit erratic and not a smooth
transition between two waveforms with maximums at both points.

I don't like to put my 184 at risk to try this. As to the theory I can only think that the two peaks appear because the filter L18/L19 is double-tuned (as are all those filters between stages); I might be totally wrong. Suppose L19 is tune below the 10 MHz crystal frequency. Then I expect peaks when (very roughly) L18 is tuned to the crystal frequency and when L18 is tuned to the same frequency as L19. Perhaps the idea now is to tune L18 midway and then tune L19 (and C108?) again as prescribed. Repeated until the results are satisfactory.

W.r.t. crystal temperature, in my 184 the crystal housing temperature stabilizes at about 38 C (measured with IR meter) while Tamb is 11 C.
The crystal frequency goes up (light on) and down (light off) with 1.2 ppm between the limits. If the (average) oven temperature equals the crystal design temperature then I would expect a maximum frequency or a minimum frequency midway in each on and off traject (or at least a stationary point midway, not simply monotone increase or decrease). Of course the oven temperature can have drifted away due to aging of the bimetal (?) contacts.

Albert

Keyword spamming? One guy that I used to know included the phrase "not
HP calculator" in the title of all of his E-bay listings so that his
auction listings would show up everytime anyone searched for the words "HP"
or "calculator".

On Wed, Dec 8, 2021 at 12:33 PM Robert Simpson via groups.io
<go_boating_fast@...> wrote:

Ha, maybe it has special HP features

In his defense, it doesn't actually SAY "Tektronix" on it anywhere, except in the old-style logo, which is not so easy to read.

Man! All he wants is a chain hoist in exchange (US made, though), and the scope has the front cover, probes, accessories, and all the knobs are in good nick! If I were on the left coast, and had a chain hoist lying around, I jump on this.

-- Jeff Dutky

I guess the guy dont t read good or sumthin'....
Jeff Kruth

Ha, maybe it has special HP features

Hi All,

I'm in need of another scope cart (or 2).
I'm looking specifically for Tektronix Model 3 Scope Mobile carts.
I'm willing to drive a fair distance from Detroit to pickup.
Will pay cash or trade equipment.

Please contact me off list if you have one for sale.

Cheers,
Chris