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For printed circuit board use, there's a paper/toner transfer sheet that is printed on (laser printer), laminated to the board (makes the toner melt), and then is soaked off (special coating (cornstarch?) on the paper.

It is also recommended for decals, so printing on some of it, soaking it, and using it as a transfer might help.? Never tried it, though.

Harvey

Greetings!

I need to re-letter the skirts for some of my scope knobs. Has anyone done that here?

I am thinking that black vinyl reversed letters on transfer stock would work. I found a few sites that provide that service, but I am not sure if they can deal with the small size that would be required. Not sure if a design tool is available online.

Other suggestions are welcomed!

Thanks,

Barry

Hey all,

So, based on some exchanges in the thread about the Dennis Tillman PCB for the 577/677 build, I am definitely on my way (parts are coming). But I wanted to start a new topic on the 577 itself to get some advice.

This is a 577 that's in very nice condition and when I bought it in 2020, it was sitting in the seller's garage with a trace on the screen. I realize that doesn't mean a whole lot. But here we are 5 years later and, at some point, I'm going to have to bring her back to life.

So, I'm looking input on next steps. For example, should I warm it up slowly (and over what period of time) with my variac, etc. Or maybe do some diagnostics on the power supply before plugging into mains. And so on. I have a variety of test adapters but, given the power up sequence suggested in my operator's manual, the one that I don't have that I apparently need is the axial diode adapter

Thanks in advance for any replies.

David

+1 on all of Menahem's points. In fact, I'd advise, instead of looking for
an NOS cap (I think this is what the OP is asking), procuring a new one of
adequate specifications, which will likely have far better specs and
smaller size anyway.
No application I'm aware of is sensitive to the exact value of an
electrolytic - particularly as all of them, and especially the old types,
have relatively large tolerances.
Radu.

On Sat, Mar 29, 2025 at 10:18?AM M Yachad via groups.io <yachadm=
[email protected]> wrote:

Not speaking from any particular authority on the merits of THAT
particular cap, but why not a regular 105°C 390uF or 470uF rated at 80V?
The circumstances which require an EXACT replacement of the original, are
very few and far between.

Menahem

There is a tek500 group. I found this very interesting since I am currently wrapping up a 10Hz->100kHz ultralow distortion signal generator project (-140dB THD, so far, at 1 kHz)

I just cracked it open and checked the DC voltages and ripple. Everything was well within spec. The inside also looks very clean!

I didn't notice the tag earlier but it appears to have been taken from a hospital environment. It was a bit of a pain to pull the chassis from the case. Of course, the only tiny dent on the top of case was putting enough pressure on the side rails to make it difficult for the chassis to slide out without resistance.

I'm guessing you might be right and maybe the caps needed to reform or something along those lines. At this point I had the scope running for hours. Left if unplugged for a few hours and had it running for a few more hours and everything seems to be ok.

I'll probably recap it in the near future as I plan for this to be my everyday scope w/ my 2232 for 'slower' stuff.

The 'green screen of death' had me a little worried but feel relieved that it's been stable since those initial issues. All functions I've tested so far have worked perfectly. I'll need to play around with the menu and measurements system a bit more but the few quick measurements I've made were good. I need to read about the menu/measurement section as it has more features than the 2245A which I've been using.

I appreciate all the responses. I'm sure I'll have more questions!

OOPS, not a 'scope. Sorry, delete if necessary.

On Sat, Mar 29, 2025 at 12:57?PM Jay Czaja via groups.io <jmczaja=
[email protected]> wrote:

Thanks again guys! The 2247A has been running overnight with signals in
each channel and everything has been humming along ok, no lockups.

Sounds like a keeper to me!
If the scope has been in storage for a while, it's possible that the power
supplies stabilize as the caps reform or warm up or some such. You may
still want/need to recap it, and I've never heard of a case where the
calibration is thrown off by improving the power supplies. I've never
worked on a 2247A, though, so YMMV.

On Sat, 29 Mar 2025, Jon Nicoll wrote:

Until recently DigiKey (?) had replacement buttons in stock. It is just that
button part that is attached to the plastic or metal driving rods that were
used in many devices with such buttons, not just Tek 24xxx. They even had it
is different "eye" colors, not just that acid yellow. I still have some red
and yellow ones somewhere in my stock.

The exact one used in 2465B and such was C&K F08010106 (Yellow) or F08010108
(Green).

BTW, they were also made square and rectangular caps, not just round.

Here is the DigiKey part number page (out of stock, but does have datasheet
with all those buttons of all types and shapes (at the end of the datasheet
which is for pushbutton SWITCHES and those buttons are at the end of it:



Once upon the time they actually had those in stock and I was able to
purchase some.

BTW, if you enter "F08010106" in Octopart search you'll find many still in
stock and they are dirt cheap -- e.g. Arrow/Verical has 160 of those in
stock as of right now for 64 cents apiece. They even have them in different
colors, Yellow, Blue, Green, ans Orange (last 2 digits 06/07/08/12).

As an afterthought, will probably go buy some more in all colors, just to
have spares...

Thanks Greg - I got a replacement but the fine details of how this one operates does not exactly match that used in the 2465. As you say, the plastic construction is pretty delicate.

I will take another look but unless I find an easy source I think I am going to live with this.

Regards, Jon N

---
*
* KSI@home KOI8 Net < > The impossible we do immediately. *
* Las Vegas NV, USA < > Miracles require 24-hour notice. *
*

Not speaking from any particular authority on the merits of THAT particular cap, but why not a regular 105°C 390uF or 470uF rated at 80V?
The circumstances which require an EXACT replacement of the original, are very few and far between.

Menahem

Sorry I couldn’t help more, Jon.

I have one of the Hekimian 41-01 transmission test sets here that is part of a test suite. It has 20 of those switches on it. If you decided to go the extra mile maybe someone has an old parter available but still don’t know if the switch assembly is the same as in the Tek scope. Probably not.

There is one on ePay at a ridiculous price but the photos will give you an idea as to what I am talking about. All of the indicators on the switches show black (off) & green (on).

Greg

Thanks again guys! The 2247A has been running overnight with signals in each channel and everything has been humming along ok, no lockups.

I'll put it on the bench sometime today or tomorrow and check the DC voltages per the service manual and check for ripple. I'll have a look at the diodes and check their marking and see what's what.. If any electrolytics require replacing, will this throw off the calibration? I don't have any of the fancy gear to do a proper calibrations (PG506A, marker generator, etc).

I have a really nice 2245A and enjoy using it and always wanted a 2247A. This particular one seems to be clean and in very good condition overall. The trigger section on the 2247A seems better than my 2245A as well. The 2400 series scopes look nice but the 224x's are probably more scope than I'll ever need. I also have a nice 2232 that I like using for the DSO section. I mess around with building synthesizers and the 2232 is nice for catching really slow events.

Thanks again!

On Fri, Mar 28, 2025 at 06:12 PM, VE6WMR wrote:

Jay,

I have two 2465's here, and they're known for quite a few gremlins, including
NVRAM battery issues, among other problems.

Comparing a 2465 to a 2247A is a bit like apples and oranges, but understood the well meaning intention to be helpful in the sense that both are old.
But for one luckily the 2247A does not rely on NVRAM to store cal constants.

As suggested check all voltages and ripple to make sure they are within spec.
Also while you are in there, check power supply diodes, and any with ZM or ZS markings needs to be replaced as they are known to get leaky over time and cause problems. There are 17 of these diodes on the 224x (and 2252 same series) scopes power supply. Use fast diodes like MUR160 (600V 1A) or similar. Do not use common 1N400x.

Also replace the 3V Lithium battery, its only meant to hold the setting of the last session, no calibration at risk.

I have both 2465B and 2247A scopes, but the 47A is usually my go-to scope 95%.

Anyone know where i can get one of these?

Any of you guys taken this board out? Whats the procedure.

This is an interesting article about "Paul" building a modern day version of the Tek SG505.



Here's the link to "Paul's" DIY electronics blog on it where you can keep abreast of his progress (as of early March he had prototype PCBs but was missing some parts).

It’s not unreasonable to expect that the power supply is in need of a
recap, and a marginal power supply could cause random problems.

In your shoes I’d pull the case and measure the power supplies for voltage
and ripple. There’s typically a table with allowable values in the service
manual.

?ann f?s., 28. mar. 2025 kl. 23:27 skrifa?i Jay Czaja via groups.io
<jmczaja@...>:

Thanks Greg - I got a replacement but the fine details of how this one operates does not exactly match that used in the 2465. As you say, the plastic construction is pretty delicate.

I will take another look but unless I find an easy source I think I am going to live with this.

Regards, Jon N

On Fri, Mar 28, 2025 at 09:12 PM, VE6WMR wrote:

Jay,

I have two 2465's here, and they're known for quite a few gremlins, including
NVRAM battery issues, among other problems.

In my case, I have two good ones, and I can have an excellent one by parting
them together and renovating. I'll cast off the remaining wreck.

You can do the same with yours. It's quite an old scope, repairable, with good
manuals, but far outside any warranty support. Why did you buy it then? It
isn't reasonable to expect these to be without major flaws needing to be
addressed. If you're ready to do that work, dive in.

If you're not willing to do all that work, you should return it and buy a new
overseas model with warranty. Rigol, Instek, Owon, etc.

It's something like owning an older car. Much more repairable, but needing
much more time into it.

Thanks for the reply and perspective. I fully understand these are old scopes and have no problem putting in a little work to get a scope working as it should. I just get a little spooked when I can't reproduce a problem.

Earlier, I turned the scope off for about an hour and started it up again and as of now the scope has been running for about 7 hours without any issues. All of the functions I've tested have been working as expected. All channels work, the display is sharp, measurements seem accurate, triggers are working well, etc. So far the only issues I encountered were the first few startups after unpacking.

I have a little bit of time to decide what to do and whether to send it back or keep it. I'll play around with it for the next week or so and see if the gremlins misbehave.

Hi:
Where are do you live if we want to pick
them up?
Walt

On Thu, Mar 27, 2025 at 6:02?PM W7HPW Radio via groups.io <t265frc10=
[email protected]> wrote:

I have 3 CRT's that came with a lot that I acquired 2 154-0910-00 for
a 492 Spectrum Analyzer and 1 154-0934-00 for a 494 can anyone use one or
all? I don’t have either of those analyzers so if one of you have one of
them here's your chance to score a CRT. The 2 910 are in the original
cardboard holder all with Tektronix tags indicating part number. They look
new but actual condition is unknown.

Let me know if you want one!

Mark
W7HPW

Real Radios Glow in the Dark