开云体育

On Wed, Nov 19, 2014 at 10:57 AM, John Griessen <john@...> wrote:

Someone mentioned still using WinXP and updates to it that are available, even though
Microsoft has abandoned it. Where to look?

Type this in a command window:

reg add HKLM&#92;SYSTEM&#92;WPA&#92;POSReady /v Installed /t REG_DWORD /d 1 /f

Then run Windows Update/Microsoft Update as normal.

Someone mentioned still using WinXP and updates to it that are available, even though
Microsoft has abandoned it. Where to look?

Thanks Kurt, interesting data!
Albert

yes, I too thank you for the heads up, and have ordered the kit. Can
you tell me how it does as a ESR meter?

"Having sex is like playing bridge. If you don't have a good partner,
you'd better have a good hand"
--Woody Allen--

Free Tek 585A (s/n 009721) on cart.
It was working last time I checked but needs some TLC.
It is complete, free to anyone who can pick it up. You must take cart also.


I have no time to devote to this project.


Thanks,
Victor Silva
203-233-8902
In Watertown CT.

It's important to point out that sampling plug-ins drive the horizontal display of the scope.
Make sure it's connected to the scope the right way.
There's a free run setting for the trigger. I haven't used a 1S1 in a while, I don't really know anymore what free run does, but let's try that.
I recall you can display a line with no input.

It turned out to be a faulty C853 on the main board. I put a DMM across it in circuit and got about 300 ohms, even when I reversed the leads. That seemed suspicious to me so I lifted one of the leads. Still measured 300ish ohms. Did a quick capacitance check and instead of 0.47uf, I got 0.02nf. Not a happy capacitor.

Congrats on finding your issue.
I guess if panos' 2445 has the same issue, a quick way to diagnose it would be to measure the DLY_REF line resistance ground and the -1.25V "rail".
The easiest way to do it is probably by disconnecting P511 from the A5 board, and measuring at the connector.

I see a cable with a toroid on it and the connector is hanging loose. It is near the high voltage lead. I will find out where it goes. Could it be THIS simple?

There was a recent note on a similar failure here <>. A1C712 is a .47uF ceramic, gone leaky here to compromise sweeps.

This sounds awfully similar to the behaviour of the 7S11/7T11 combination
when it isn't triggering. It doesn't really semm to have an "Auto" mode,
and dives off screen (downwards) if you don't get the stability/trigger
controls set right. If find it very tricky to get a decent trigger every
time I use them.

Regards,
David Partridge

What about a visual inspection? Are you missing parts?

Also,

I have a couple of these 1S1's and get the same response from both. So, either they both share the same fault or more likely, I don't know how the heck to run my scope. I suspect the latter. But anything is possible I suppose. I am at first trying to determine which of the two plug-ins to restore. Then I can go from there.


I do have an extension cable for the scope and plug-in, but had not wanted to move forward until I spoke with you all here. My next step was going to be just go through the CAL procedure and check all the power supplies in the PI and hopefully reveal something there. I would like to at least try to get this "trace to appear, as the restoration might be simple. HA!!!


Thanks for the help folks.


Cheers,


David

Good Morning All,


I am trying to restore this 1S1 back to working condition, but I am having difficulty just setting it up in the first place. I am using it in my 556 and having a heck of a time getting a trace at all. I have been through the archives, my manuals, and I am pretty certain I have it set-up properly, but not 100%.


What I do see on the display when I set everything up as per the 1S1 Manual is a remnant of what appears to be a beam of phosphor being lit up from below the display. The "light" or "beam of light" is about 5mm wide, can be controlled by the HORZ POS on the scope, and its origin remains below the bottom of the CRT as it looks like one of those HUGE crowd gathering, attention getting, movie lights that they put in parking lots to attract visitors. Defined horizontally about 5mm wide, shooting up towards the middle of the CRT. I would say the height is about 20mm and quickly fades. Also, it seems that in order to see this "trace", I have to push the intensity about 1/4-turn higher to be visible. This does happen no matter which vertical side of the scope I try.


Please keep in mind that this is by far the most complicated of plug-ins I have worked on and I have ZERO sampling plug-in experience.


Any Thoughts?


Cheers,


David

Insulation resistance should be many megaohms, at DC.

The standards generally specify a leakage current at operating voltage
and a withstand voltage for the hipot test, rather than an insulation
resistance.

ST



On Wed, Nov 19, 2014 at 11:52 AM, Bob Vines bobvines00@...
[TekScopes] <TekScopes@...> wrote:

I haven't worked on any power (or any other types of) transformers
yet, but _may_ have a failed one in a (spare) linear power supply for
a PDP-8/E. Is there a "rule of thumb" for when the resistance
measured between either the primary or the secondary and the core
shows when there is a problem with the transformer? Manfred implies
that certainly only 10Kohm is too low, and others in different
discussion threads here have mentioned X-number of Mohms as showing a
good transformer, as far as shorts are concerned.

Where is the "dividing line" between good vs. bad resistance readings
when doing simple (resistance) tests like this (on un-powered
transformers)?

I'd like to use this _basic_ information when working on anything with
a transformer, including my 'scopes.


Thanks,

Bob

In Manfred's & Tom's discussion on Testing with Floating 'Scopes,
Manfred stated (on Tuesday, 18 November, 2014 at 0718 (PST)):

[snip]

"I haven't yet given my GFI's any reason to trigger, while working with a
floating scope. But one of the GFI's has already done a good job, by triggering
repeatedly when I was using an old tube-type signal generator. That signal
generator had an ungrounded cabinet and two-prong power plug, like all old stuff
does, and used to give a slight tickle when touching it. Not uncommon, it's
caused by the capacitances between the circuit and the cabinet. But then the
tickles started getting stronger, and some day the GFI started triggering when I
connected the signal generator to a grounded circuit. Time to check the
generator. It turned out that its power transformer had severely degraded
insulation, and had a resistance like ten kiloohm from the primary to the core!"

[snip]

====================

I haven't worked on any power (or any other types of) transformers
yet, but _may_ have a failed one in a (spare) linear power supply for
a PDP-8/E. Is there a "rule of thumb" for when the resistance
measured between either the primary or the secondary and the core
shows when there is a problem with the transformer? Manfred implies
that certainly only 10Kohm is too low, and others in different
discussion threads here have mentioned X-number of Mohms as showing a
good transformer, as far as shorts are concerned.

Where is the "dividing line" between good vs. bad resistance readings
when doing simple (resistance) tests like this (on un-powered
transformers)?

I'd like to use this _basic_ information when working on anything with
a transformer, including my 'scopes.


Thanks,

Bob

Thanks David,

I like the 2khz test I'll try that.


Cheers


Alan

Thanks for the kit suggestion, I have ordered something similar already But this seems good too.

Cheers


Alan

Thanks Dan,

I may take you up on that if I can't get any sense out of the printouts, but yes its the layouts I need maybe I take a picture of the real thing and expand them.


Cheers


Alan

I have a real 475A hardcopy manual, if there is anything you'd like a clearer copy of I would be happy to scan and PDF. The layout pictures are pretty bad, even in the original manual. The 475A is a slightly higher bandwidth version of the '475. I don't think the power supply would be different, but maybe someone can comment on that.
Dan