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I hate those when they are used as transistor sockets !
The lead dress is slightly different to that used in most transistor
testers, so when I pull a x'istor to test, I need to spread the leads a
little to get it back into its socket.
I am currently working on a 5L4N which is full of the things.
Tim P


On Wed, 23 Apr 2025 at 10:03, David C. Partridge via groups.io
<david.partridge@...> wrote:

<>



Cheers, David

<>



Cheers, David

One quick bit: Don't use that 10meg resistor (or any other ordinary resistor) again for HV measurement.?A typical voltage rating for a half-watt resistor is just a few hundred volts, above which HV will arc through/around it, effectively shorting it out. If you don't want to blow things up, you'll have to use a proper HV probe.

The multiplier hasn't been manufactured for many years, so you'll either have to find a used one somewhere (which itself could be defective), or make your own replacement.

Tom

My lovely 465 died immediately after I finished some cosmetic repairs. Low voltage test points all look good. No beam, except when I disconnect the ground lead of the HV multiplier as suggested by VintageTek Museum on youtube (). (I also hear some crackling sounds with the multiplier disconnected, so I haven't run it in this state for more than a few seconds.) Could the problem be anything else besides the multiplier? I have a digital scope but no high voltage probe. To measure high voltage DC I have been using a 10MOhm resistor and analog ammeter, but of course that's a significant load.

If the problem is the multiplier - part number 152-0552-00 - does anyone know if they're still available? I see that a couple members have built replacements, and I would really appreciate a schematic and/or component values. The location of the multiplier within the scope, and the requirement of potting, will make it difficult to troubleshoot a DIY replacement and I have little high voltage experience. So I'd like to get it in 1 shot.

The AS15 suffix is not necessary. This suffix means the lamps have been burned in and tested for current for series circuits. Use the one that is physically the same as the original. Replace the three then keep the good ones for spares.

Mark

On Tue, Apr 22, 2025 at 9:28?AM Bobert29 via groups.io <jg1647=
gmail.com@groups.io> wrote:

A5 looks ok, I did check my work when I finished, but I’ll re-check.

This sounds like either the MPU is not running, or else it's not
communicating with the front panel (FP).
Did you reconnect both ribbon cables from the A5 board to the FP?

Found several at Mouser that I don't know which to order
The specs look the same and Mouser couldn't tell me the difference
CM7152
CM7153AS15 The first one is 30% cheaper..

Thoughts?

A5 looks ok, I did check my work when I finished, but I’ll re-check.
A2 - A3 comb pins and cables look good.

On Mon, Apr 21, 2025 at 07:37 PM, Adam R. Maxwell wrote:

If you're using a Mac, you can try using curl in the Terminal (assuming it's
still installed on recent OS versions), and avoid firing up a VM.

Adam;

I don't "fire up the VM" to access the TDS 3054C 'scope. I use the Windows 11 VM on my Apple silicon MacBook Pro to run a variety of Windows-only electronic engineering tools.

I have a good Windows laptop, but my MacBook Pro is newer, faster, and more "fuel efficient". It's really convenient to be able to access the 'scope while I'm already working within the Windows 11 VM.

I will experiment with 'curl', though, as there are times when I want to access the 'scope from MacOS, without reverting to the Firefox browser.

B.T.W. macOS Firefox self-updated from v129.0.2 to the current v137.0.2 ARM.... the new version is still talking reliably with my TDS 3054C

Mark

Check that the Comb Pins which connect the A2 and A3, are properly aligned, AND that the multicolor wire harness connecting to the A2, is also on the correct pins.

On Apr 21, 2025, at 19:19 , Mark Davis via groups.io <markad7ef@...> wrote:

On Mon, Apr 21, 2025 at 12:31 PM, Philip Freidin wrote:

I have been using the following script (batch file) on Windows 7 Pro
for over a decade and Windows 11 Pro more recently.

Philip;

Thanks for the tip!!! Your wget script works great on the Windows 11 ARM environment I'm using under VMWare on my Apple silicon MacBook Pro.

If you're using a Mac, you can try using curl in the Terminal (assuming it's still installed on recent OS versions), and avoid firing up a VM. Using a URL I happened to open a minute ago here, something like this should work:

curl -o "FooBar_$(date "+%Y-%m-%d %H%M%S").gif"

Adam

On Mon, Apr 21, 2025 at 12:31 PM, Philip Freidin wrote:

I have been using the following script (batch file) on Windows 7 Pro
for over a decade and Windows 11 Pro more recently.

Philip;

Thanks for the tip!!! Your wget script works great on the Windows 11 ARM environment I'm using under VMWare on my Apple silicon MacBook Pro.

Mark

oops, clarification:

The center pin on the left of the array [...]

This should say phototransistor array.

There has been some discussion over the years as to how to disassemble the knobs for repair/cleaning. I got mine fully apart (thanks to the photos others uploaded when they got stuck) and uploaded photos.

For knobs designed like mine, the black cap pops off and there is a screw underneath. Until the screw is removed, the smaller knob cannot be separated from the larger.

The clipped off leads on the LED package allow testing each LED individually if desired; mine have a Vf of ~1.5v. Alternately, 7.5v across the array results in them just starting to glow.

The center pin on the left of the array (as oriented in close-up) is common. It seems the transistor on the lower left pin in the array is bad, as it doesn't respond to light; the others do.

Does anyone know where to find a 1x5 phototransistor array with spacing of ~1.175mm c-c?

The schematics don't show much beyond the fact that the array is biased with +/-15V, and nothing shown in the opto section of the 1982 common design parts catalog looks even remotely close.

Regards
Mark

mark999 <mpictor@...> added the photo album Tek 7L5 resolution & frequency knob disassembly ( /g/TekScopes/album?id=301996 ) : 7L5 knob encoder disassembly

Update:

I have several bids out to laser cut the skirts and print the lettering for the SC502, SC503, and SC504.

If you are in need of a skirt let me know I will include it in the order!

Thanks for all your comments.

Barry

I tried progressive wound but it didn't work properly for two reasons, the first being the high potential at the intersections at the ends obviously and these eventually broke down in a 556 I owned....The second being the unblanking circuit had difficulty on high sweep speeds causing the trace to skew I suspect from the latent charge in the windings hysteresis or maybe even self capacitance... Basket wound solved both these problems. I do also put a layer of fibreglass tape every 100 or so turns to further protect any arc-over. Yes it was a lot of effort but when my 570 HV transformer failed a couple of months ago, I was able to repair it in 8 hours, and where do you find one of them!

Ooops...

Also, my TDS3064B is setup with a static IP address on my local LAN
which is 192.168.1.70

I have a TDS3064B, so this is probably useful for you.

I have been using the following script (batch file) on Windows 7 Pro
for over a decade and Windows 11 Pro more recently.

You need to install wget , and add its location to PATH

The two FOR statements generate a unique name, and the last line
displays the image on my computer because I have it setup to
run a viewer if a .png is given at the command prompt.
I also created a desktop shortcut to the batch file, so whenever I want
a screen capture, I just double click the shortcut.

REM Get current image from TDS3064B scope, and name it uniquely
REM
REM Updated for W7-x64
REM

FOR /F "tokens=1-4 delims=/ " %%I IN ('DATE /t') DO SET mydate=%%L_%%J_%%K
FOR /F "tokens=1-3 delims=.: " %%M IN ("%time%") DO SET mytime=%%M_%%N_%%O
wget --ignore-length 192.168.1.70/Image.png

rename Image.png TDS3064B_screen_%mydate%_at_%mytime%.png

TDS3064B_screen_%mydate%_at_%mytime%.png


Cheers,
Philip

Well, I think the first step would be the re-check the work you did on A5 board, e.g. soldering of the components, since it seems that the problem has got worse after changing the components. I assume , when you mentioned corrosion that the SMD capacitors leaked. If J119 voltages are correct, I'd assume that Rifa caps were changed correctly. So, again, I suggest check the work you did on A5.