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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

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.

Hi folks. I recently purchased a Tek 2247A scope and upon testing it for the first time, it locked up when testing the B sweep with a msg that said

'INVALID INTERRUPT FROM 0993:F082'

When I rebooted, the screen has an indecipherable error message that appears to read something along the lines of 'Part Number 100-xxxx-00' with a bunch of exclamation marks. I couldn't clearly read what the part number as it was out of focus and could get it to focus well enough to read the numbers. The 'Auto Level' and 'Auto' LEDs were flashing which indicates both a RAM and ROM problem according to the service manual. The SGL SEQ LED was also flashing but there's nothing in the service manual that mentions that LED, or at least nothing that I've found.

I let the scope sit for 10 minutes and it booted back up in service mode and gave a failed battery warning, and ran through self calibration. I left the unit on and it locked up after about 10 minutes with the same error as before.

After the reboot I went into the service menu and ran the self test 'until fail' and the test ran for 30 minutes without issue. I also ran through the self calibration once more.

It's now been powered on for a few hours without any problems or locking up and all functions 'seem' to be working as expected.

Thoughts? Would something like this be caused by a battery issue? That seems like an easy fix but if it's something deeper, I'm not sure if I'd want to chance it.

Thanks!
Jay

Those switches were originally made by ITT Schadow many years ago and used to be available in many styles of buttons. I’ve seen failure of the indicator several times due to the delicate plastic nature of the way it is built. Never have had to replace one in the 2465 though.

Hekimian Laboratories was known to generously use this style of ITT Schadow switches in their telecommunications test sets which can be found on ePay.

Greg

Actually, I'm going to reply to my own posting...

- I have realised that getting access to the power indicator is easier than I feared - just undo the Torx screws and take the front bezel off.
- It looks like the replacement part is not exactly the same as the original, and will not do the job ;-(. I'm going to give up on fixing this small fault.

Regards, Jon N

I can't help you on the circuit boards, but to you or anyone needing a 575 curve tracer, I want to sell mine.? I don't want to ship it.? Many other Tek items if interested.? I live not far from Chicago.? N9ESS@...? Carl

Hi, I am looking for one of Dennis's PCBs and I think the one you wrote about is the one I'm looking for. He and I were discussing it in emails a few years back and I got COVID and was down for a while and so I lost track of certain threads and projects that I was working on. In one of his last emails to me, he noted that he had revised his paper for the Tek SCT/TubeTester build and sent me his lastest revised designs for adapting a 577 curve tracer to an EICO 677 tube tester. I have that paper and I also own both pieces of gear. I was wondering if you still had your board or if someone else had one that I could acquire. Thank you.

Hi Clark.

Thanks for the replies.

The reason I asked, is that I am in Brazil and shipping from the US often starts around $40. Couple that with the $20 item price, and then the 100% import tax on both item AND freight, then it would cost around $120 for those five transistors to be here, and I actually only need one.

I think I'll try the TIP 102 and see what happens? At least they cost less than a single Dollar.


James

Hi All
I have a Tek 2465 which has a small fault I am hoping to repair. This is the 'sleepy eye' power indicator on the front of the 'scope.

The power switch itself works fine; but the indicator shows the high-vis 'on' state even when power off. It's a small fault but I would like to sort it.

I have managed to find what I think is the replacement part. I had hope it was going to be straightforward to fit it to the end of the shaft running from the front panel to the switch; but having taken the outer 'sleeve' of the 'scope off, it looks like there is going to be more work to get access than I thought.

I have stripped this scope down before (I 'recapped' it a few years ago) but I have forgotten most of the order in which I need to do things. Any pointers as to what I should do next?

Thanks, Jon N

Need cap 290-0585-00, 350uf, 75V. Anybody selling? I'm in MD 20882.

On Mar 27, 2025, at 20:41 , Adam R. Maxwell via groups.io <amaxwell@...> wrote:

In attempting to get the barrel at the right depth and snug the locknut down, I broke the center contact holder inside the bias return, and it looks exotic and irreparable. I'll see if I can get some photos so others know what not to do.

Actually not sure if I broke this or if it was broken before, since it was loose, but there are signs of scarring inside. Anyway, it sure is broken now. The series of photos shows how the bias return is assembled, and I see no room for error in setting the depth of the barrel connector and tightening things down, since there's no spring in the system.

/g/TekScopes/album?id=301504

Construction is similar to the S-4 sampling head 3.5mm connector, but the collar seams are hidden by the outer plastic sleeve, so it wasn't immediately obvious how it should come apart or be reassembled, since the steel locknut is fully recessed.

/g/TekScopes/photo/301504/3900054?p=Name%2C%2C%2C20%2C1%2C0%2C0

Anyone have a 119-1164-00 Bias Return they want to part with?

For now, I've bypassed Option 3 phase lock, and it's reassembled and working, so I guess this is progress of sorts.

Adam

The following photos have been uploaded to the 492 Bias Return ( /g/TekScopes/album?id=301504 ) photo album of the [email protected] group.

* IMG_2343.JPG ( /g/TekScopes/photofromactivity?id=3900053 )
* IMG_2344.JPG ( /g/TekScopes/photofromactivity?id=3900054 )
* IMG_2345.JPG ( /g/TekScopes/photofromactivity?id=3900055 )
* IMG_2346.JPG ( /g/TekScopes/photofromactivity?id=3900056 )
* IMG_2347.JPG ( /g/TekScopes/photofromactivity?id=3900057 )

*By:* Adam R. Maxwell <amaxwell@...>

I looked at eBay and there are many sellers of MPS-U45; some fair prices and many not fair. One is offering five for $20 shipping included.

On Mar 27, 2025, at 17:00 , ed breya via groups.io <eb@...> wrote:

I'd say it's most likely a bad solder joint or broken part - something in series with the signal path such that it goes open, but still has some capacitance to couple an attenuated version of the signal. A short of signal to ground can act that way too, say from a shield braid strand, solder glob, or loose piece of hardware or wire clipping, but I think it's less likely than an opening scenario.

I think this is entirely correct. Much to my chagrin, I could reproduce this by heating a replacement 829 MHz 2nd converter, which also explains why I couldn't find a problem in the IF select board: it's something next to the converter, either the bias return or the transfer switch. <headdesk>

Sadly, I am now in need of a bias return. The SMA connector on it was loose (the one connector I apparently never tightened), and unfortunately the barrel on the brass device was loose in its locknut. In attempting to get the barrel at the right depth and snug the locknut down, I broke the center contact holder inside the bias return, and it looks exotic and irreparable. I'll see if I can get some photos so others know what not to do.

Anyone have a 119-1164-00 Bias Return they want to part with?

thanks,
Adam

I have a few MPS-U45 (151-0390-00). If you only need one or two, I can help.

Clark