开云体育

I have added a photo album with pictures of the two replacements I have found compared to two sizes of thumb nuts from Tek instruments: /g/TekScopes/album?id=266234

I have also found another candidate in this item on eBay:

I will post pictures when the parts arrive.

-- Jeff Dutky

Mark,
Thank you for the effort to inform me about the secundary voltages. I expected this already.
If I decide to use a 454 transformer, which is identical to a 453 transformer, I have to do some cable dressing, as these transformers are horizontally arranged, with respect to the 453a transformer which is vertically arranged.
Anyway thanks again for your info.
Fred

Bruce,

If you were building a replacement for one of these delay relays (hypothetically speaking, maybe for a 533A), would it be enough to have a timer that cut a relay in after a fixed time? Is that really all that the delay relay is doing?

Might there be another way to determine when the heaters are at temperature, like by monitoring the current through the heaters, or even by directly sensing the temperature of the tubes themselves?

Just curious (though I am in the process of refurbing a 533A, and this may be useful information when I get to the point of applying power to the instrument)

-- Jeff Dutky

I know folks have been talking about this for a while and it looks like
someone actually did it.



Description is a bit on the thin side and if you're going to go to all that
trouble it seems that you should calculate the parameters instead of making
you calculate them off the screen grid. Apparently you do get cursors, meh.

Disclaimer: no connection to whoever did it
--
Paul Amaranth, GCIH | Manchester MI, USA
Aurora Group of Michigan, LLC | Security, Systems & Software
paul@... | Unix/Linux - We don't do windows

just one more thing...

yeah, right. It is pretty warm in my lab in Calif. today -- I attempted a full normalization just now, it succeeded. Perhaps this is more proof I need to do the real work now from great posts such as Mike/WZ5Q, Randy/AB9GO, Marcus/PP5MS (et al).

Now I'm thoroughly convinced I need to check PS voltages/ripple, and to order two batteries -- check the caps and do the due diligence. I am headed to the copy/print store to make printouts of the 11x17 schematics.

Appears surprisingly "normal":

Thanks for your virtual patience,

R

Dear all,

I have received datasheets in PM's off the list and also links in this thread.

Thank you all!

Cheers

Ulf Kylenfall

Just one more tidbit (before I decide if I'm going to dig deep into it).

Enabling debug diagnostics and re-running the Frequency Normalization indicates this:

“ERROR in MAIN DAC OFFSET: Cannot center start spur”

Explanation: "Beginning at 10 MHz/div span, the start spur was located and
centered, then span was reduced. In 1 MHz/div span, the signal
could not be centered within 30 horizontal storage bits."

I have a “oddity”, a +30dB rise of about 70MHz width:

1486 MHz
1498 MHz
1558MHz

Does anyone have an OCR of the 2712 Service Manual?

Thank you
Ronan

The following files have been uploaded to the Files area of the [email protected] group.

• /1953_Radios_Master_18th_Edition.pdf
• /1957_Radio_Electronic_Master_22nd_Edition.pdf

By: udtmang@...

Description:
Has some data on the Amperite relays

Ulf,

I designed these into things about fifty years ago. The Amprite type numbers generally provided the data. For example a 117NO60 would indicate a 117-volt unit with normally-open contacts that would close 60-seconds after power was applied. These thermal delay relays were often used to delay the application of plate voltage until cathodes warmed up.

Bruce, KG6OJI

Sorry - I included a graphic of the pinout on my first reply, but I guess
it was blocked.

Here's the Web site that has it - along with a link to download a PDF.



Steve Horii

On Sun, Jul 18, 2021 at 3:37 PM ulf_r_k via groups.io <ulf_r_k=
[email protected]> wrote:

Dear forum,

I have been trying to find datasheets for the Amperite time delay relays
used in older Tek scopes. They are built in 9-pin tube glass envelopes.

Looked in w140.com but maybe not long enough to find any.

No hits by simply googling the type number...

Is there someone who knows where to find specs?

Cheers

Ulf Kylenfall
SM6GXV

For instance .
Albert

Dear forum,

I have been trying to find datasheets for the Amperite time delay relays
used in older Tek scopes. They are built in 9-pin tube glass envelopes.

Looked in w140.com but maybe not long enough to find any.

No hits by simply googling the type number...

Is there someone who knows where to find specs?

Cheers

Ulf Kylenfall
SM6GXV

1A4 is nice but needs some care, the large amount of wafer contacts need cleaning, and there's a lot of point-to-point wiring that can go bad. I even had a joint that was not soldered from the factory. Also it contains rare dual JFETs, and the overall design is difficult to repair and easy to damage, there's 4 channels crammed into that plugin. Maybe a nice 1S1.

But the days of trawling eBay for low price plugins were 10+ years ago. Prices are absurdly high now.

I should have added that I would like to fix this one as it has the SA option

Image of the Options/Firmware:

THANK YOU!
Ronan

Greetings Tekkies!

I've got a 2712 SA -- it had been sitting in storage some years (unknown time). When I plugged it in, the traces & text was shifted below the bottom of the display area. I let it run a couple hours; the trace & text eventually wandered up to and just above the top of the display area. The trace/text is sharp and bright, but the text is distorted especially near the top left and right extremes; and it varies.

Here are two images -- the normalization failure and the distorted text (which isn't always quite as bad as this example).

Distorted text:
Normalization issue:

I was able to get Normalization to succeed once earlier today - running complete normalization twice in succession. I then I began exploring, doing some very basic tests, after that I reset it to defaults [Util / 1 / 1] , ran the Normalization again, wherein both the Voltage and Amplitude normalization failed.

I'm reading previous posts that I should start by replacing the battery. I will pursue that and as well attempt to become familiar with the Service manual. Also I read there are some SMD-size Electrolytic I may want to check and of course power supplies.

Should any of you worked on one of these and found the same two symptoms (sometimes Normalization succeeds and other times not -- along with distorted Text and display drifting vertically after time) -- please let me know.

Thank you kindly!!

Ronan

All right enough of this bullshit

Regards,

Stephen Hanselman
Datagate Systems, LLC

On Sun, Jul 18, 2021 at 09:55 AM, David C. Partridge wrote:

Please keep politics etc. out of this group.

Amen!
--
Michael Lynch
Dardanelle, AR

Which Dallas module are you needing? Is it one of the ones that are just battery backed RAM or does it have a clock in it as well? If it is just RAM, how large is the RAM?

BobH

Fred,

The voltages on the secondaries of mine with the input set on the high range at 120V mains input: Pins 21 and 22- 6,3V
Pins 12 and 13- 17,4V
Pins 10 and 11- 18,6V
Pins 13 and 15- 90V
Pins 16, 17, 18, 19 and 20- 71, 59, Gnd. 59 and 71V
With slight line variations, the voltages will vary slightly. Voltages were measured with the loads applied and the 6,3V with graticule set at minimum so the a-c voltage at these pins is higher than the nominal 6,3V. This is a 6,3V winding. I would guess the other power transformers you mentioned would work. The 454 type may have a heavier winding for the heaters in the older S/N types. That is fine. The only thing that may be the difference is the current and slight physical size difference. If you can get one, it should work fine.

Mark

Any more Climate Change denial or defense posting will result in the offenders being placed on moderation.

Please keep politics etc. out of this group.

David Partridge (Group Moderator)