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Art,

I found an earlier discussion from Stan Griffiths (deceased) that might be useful for your panel meter replacement. I found it when I searched for the part number 149-0017-00.

Clark
——- old message below———

Hi John,

I did some research on 570 meters and here is what I found:

The 570 was built in two different mechanical configurations. The early
ones with one-piece cabinets are referred to as "square boxes" by old Tek
guys and Tek made about 500 of those, as near as I can tell by looking at
the serial numbers in the Modification Summary. When Tek changed to the
newer style, several-piece cabinet, they jumped to serial number 5000 and
went up from there. I think they made about 600 of those, as near as I can
tell by looking at the serial numbers in the Modification Summary.

All 570's up to s/n 5072 came with a 200 ua movement meter (Part Number
unknown). At s/n 5073, the mechanical size and style of the meter movement
was changed and the mounting holes are moved some. It was still a 200 ua
movement, however. At s/n 5121, the movement was changed to 1 ma (Part
Number 149-0017-00) but I think the mounting holes did not change at this
time. At s/n 5550 and up, the meter style changed again (Part Number
149-0023-00), still 1 ma but different mounting holes again.

Tek made a mod kit to replace early (200 ua) meters for 570's below s/n
5120. The kit changed the 200 ua meter to a 1 ma meter and about a dozen
resistors had to be changed at the same time.

The meter you saw on auction is a 149-0023-00 (1 ma) which is the latest
style and fits 570's s/n 5550-up. If you install it in an earlier
instrument that has a 1 ma meter in it already (s/n 5121-5549), you will
have to do some work on the mounting holes. If you want to install this
meter in a still earlier instrument that has a 200 ua movement in it, you
will need a set of the 050-0001-00 kit instructions and a bunch of new
resistors.

I have a spare 149-0023-00 meter and I think I have a spare of the very
early 200 ua movement, too, but I won't really know until I put it on my
Fluke meter checker and see.

So, John, if you are still in need of a meter movement for your 570, maybe I
can help you. Let me know.

Stan
w7ni@...

——-

Yep, 1.5KE220CA is the exact part number you need. (The 'CA' at the end of the part number means bidirectional, if it were just 'A' then it would be uni-directional)

Be aware though that the two TVS diodes you need are different part numbers!

VR4 - 1.5KE220CA
VR5 - 1.5KE250CA

Be sure to get one of each type and install them in the correct locations! :)


Regards
Jared


Jared

If indeed an LC130 meter is available and is otherwise suitable, putting a shunt resistor across the 200uA sub trivially fixes that up.

It's is the same meter in appearance, but the 570 uses a 1mA movement. There are replacement meters available on the market with the same footprint and rating, but the prices are a bit much. Then there's the problem of retrofitting the faceplate.

Hi, thank you for the support. I will place the order in the coming days. However, I have a question since English is not my native language. Is the 1.5KE220CA - bidirectional? I want to be sure before making the purchase.
Thanks in advance!
Ah! I have taken precautions with the measurements of the tantalum caps. They fit snugly on the PCB, so I don't think there will be any issues.
Best regards.

Ah ok, I understand you now.
Those Tantalums you selected seem like a reasonable choice. Having a quick look at the spare boards I have here, it seems Tek just used the same values when they swapped to tantalum as they used for the aluminium electrolytic, so a direct replacement should be no problems.

Just double check that your selection will physically fit on the footprint on your PCB.


Jared

I believe a similar 200 ua meter was used in some of the 130 L/C meters, which are much more available than 570 curve tracer parts.? Check serial number range.? You would need to change the faceplate which could be tricky.

Bob.

Hi Jared,

Thank you for your message and advice. Yes, I am referring to those caps. And I’ve decided to replace them with tantalum ones. I’ve looked on Digikey and found these: T491C336M016AT and T491C106M016AT.
Do you think they are the correct ones?
Thank you in advance for your help.

BTW, the reason I asked about that is if you swap them and the readout is centered horizontally, then the problem is likely in your vertical amplifier board. If it exhibits the same offset horizontally, then the problem is likely in the readout board. It's easy enough to try.

Thanks,
Barry - N4BUQ

I require a replacement meter for my Tek 570 curve tracer. Mine is a later version, SER # 5474. The part # is 149-017. Any help appreciated.
Thanks,
Art

Hi Steve,
Wow, this is super convenient! If word of this gets out to university research labs with old GPIB instruments and young grad students, you're gonna get busy. The price is almost twice what I paid for my 'scope, but I might buy it anyway.
Cheers,
Halden VE7UTS

On 2024-11-15 5:19 PM, HF via groups.io wrote:

I just bought a Tek 2232 with GPIB option. I see that you intentionally

installed this option on your 2232 a couple years ago. Maybe for
transferring data to a computer? It seems the original plot options
require vintage plotters. Do you know of any modern scheme to emulate
such a device and generate a bitmap or jpg file of the CRT display? Or
should I rig up a cellphone holder in front of the CRT for this?

I am just now releasing version 2 of my KISS-488, which will do exactly what you ask. This small unit plugs directly into the IEEE-488 port of your instrument, and has Ethernet and USB jacks on the other side. It provides your instrument with a website that you can access with any browser, and also gives direct access to the IEEE-488 interface via both Telnet and USB/serial. Below is a screenshot (oops - apparently groups.io treats even an inline image as an attachment) I took from my HP 8595 SA, that expects to see an HPGL plotter. Full info including a downloadable user manual at www.hxengineering.com ( ). I'm having some problems getting the ordering mechanism set up, so please be patient - it should be there within a day or two.

Steve Hendrix

On Mon, Nov 18, 2024 at 01:19 AM, rafael suarez wrote:

Hello,

I’m truly grateful for your willingness to help and for all the suggestions
regarding the repair of my TDS. I don’t want to be intrusive or take
advantage of your kindness, but there’s something I can’t figure out.
It’s about the solid aluminum caps of 33 ?F 10V and 10 ?F 10V. There are
several series available, and I’m not sure which ones would be appropriate
for the scope.

Could you please suggest one? Thank you in advance. I hope this scope comes
back to life soon.

Best regards,
Rafael

When you say Tantalum, are you talking about the small metal can capacitors with the tiny black plastic base? They are standard SMD type aluminium electrolytic.
They should all be replaced with equivalent types in any TDS500/600/700 series scope. IIRC only the C and D models had the electrolytic capacitors removed from the design.

I usually measure the size, then select a part that has low ESR and high ripple current rating, and also I try to go up a voltage rating or two if I can.
(For example, there is a cap on the front panel that is actually underrated from factory, but that's not as good as the one cap on the -ve voltage rail on the Option 05 TV Trigger board that is mounted backwards to the (incorrect) marking on the PCB!)


Jared

If you swap the cables coming from the readout to the vertical and horizontal boards, what does that show?

Thanks,
Barry

OP save time, avoid many more text notes
PLEASE take clear pix the 7704A problem, go to this group Photos section, start new album, name like like "7704ARO"

Upload the pix to FULLY AND CLEARLY describe the exact issue,

Then post the link to the photos in a message.

Amicalement

J

top is now at center, bottom is below the bottom of the screen but still there. when I use the beam finder button I can see that all is displaying well, and readout value changes when i change volts per division, it"s just in the wrong location

By this, do you mean what should be at the top is now at the center and, possibly, what should be at the bottom is not there at all?

Thanks,
Barry - N4BUQ

Thank you. I'm new to groups.io so I'll look at getting some pictures posted of the unit.

I'll give it a go reseating what I can on the readout board, hopefully it helps!

Both traces will display fine at the moment, just the readout issue

Correct yea, it appears its all there! just in the wrong position shifted down!