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J Mcvein, email me. ecmechtech@...

5"long - looks like Mike Nelson's scuba mask?
Has a light filter diagonal to view.
One here: p/n 016-053

In Vancouver, WA US

JimMc

Thank you Tony. I appreciate your efforts!

Sam

Gentlemen, to all of you who got involved, thank you for responses and an apology, I just realized that due to the brain fog and the fact that I do have a few Tektronix oscilloscopes, this is happening on the 464 model !
The whole title of the thread is wrong - should be reading Tektronix 464.
I put the wrong model in the description !

Goran,

It is best to totally recap this. I used Nichicon ULD, UCY and UHE for the secondary side and 470mfd LGR for the two screw mount cans off the mains. Raising the capacitance is fine. I did in mine. Also use a 25V for the replacement of a 15V tantalum on the 13V supply! This original will short causing a tic tic....

Replace R1651 and R1659 with Vishay VR37 types. These will be high causing the trace to be bright at first then dimming over 15-20 minutes without touching the intensity control. I did raise wattage of some resistors in mine in areas.

If yours is a 'lower' serial number, make the mod in the front ends for both channels to protect the ICs from damage when switching from 50 to 1meg. I did use a 16V cap for the 9V supply in the front ends.

Mark

I saw one on ebay just recently. I don't know if it will fit a 545A, though.

DaveD
KC0WJN


On Mon, Feb 3, 2025 at 11:21 Eric Church via groups.io <ecmechtech=
[email protected]> wrote:

Good afternoon everyone. I'm looking for one of those long tubular light
shades for my 545a, if anyone has one they're looking to part with that
would be great. Thank you, for reference in the beginning of most of Mr
Carlson's videos on YouTube the long light shade on his tek scopes is what
I'm looking for. Thank you again.

Good afternoon everyone. I'm looking for one of those long tubular light shades for my 545a, if anyone has one they're looking to part with that would be great. Thank you, for reference in the beginning of most of Mr Carlson's videos on YouTube the long light shade on his tek scopes is what I'm looking for. Thank you again.

Gotcha, just suggested it since tektronix specifically mentioned that method in a FAQ on their site:

Good luck! I had a floppy drive with strange issues like this in my tds5054b and replacement of the drive is ultimately what fixed it.

Thanks. I started with checking DC voltages of power supply and ( surprise, surprise ) there is a capacitor issue in the +140 V circuit. So there is a big ripple there.
First will have to fix this , and who knows, maybe this causes the display problem,

It really has more to do with the physical width of the read-write heads on a 1.44Mb drive .vs. a 720Mb drive. The track width of the read-write head is much narrower on a 1.44Mb drive than it is on a 720Mb drive. When using a 1.44Mb formatted diskette on a 720Mb drive, this typically has the effect of causing the previously written data (or noise) to show up on either side of the formatted track. This issue will cause read problems for the drive controller. For best results, you should always try to format the diskette using the type of drive in which it's to be used. Barring that, the diskette being used should be either a new un-formatted diskette, or should be bulk erased to remove any previous data prior to use.

All the best,
Bill W4WHW

There's some funkyness WRT to the coercivity of 720K disks vs 144Mb
disks that I don't recall the specifics of off hand. But the gist
is, the tape trick isn't known for its effectiveness.

On Mon, Feb 3, 2025 at 8:40?AM pac1085 via groups.io
<pac1085@...> wrote:

When you tried the 1.44mb floppies, did you tape over the hole? I assume you did since you knew it only supported 720k floppies, but in case your 720k floppies are bad and you didn't try it with the 1.44's, might be worth a shot.

"The floppy drives in 370A/371A support 720K diskettes only. To use 1.44M media, tape over the empty hole in the upper left corner of the diskette (i.e. the one opposite the write protect switch)."

There is a B & K group at /g/Bruel-Kjaer.

DaveD

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When you tried the 1.44mb floppies, did you tape over the hole? I assume you did since you knew it only supported 720k floppies, but in case your 720k floppies are bad and you didn't try it with the 1.44's, might be worth a shot.

"The floppy drives in 370A/371A support 720K diskettes only. To use 1.44M media, tape over the empty hole in the upper left corner of the diskette (i.e. the one opposite the write protect switch)."

I know this is not the natural place for this request, but perhaps there are like minded people here?

Does anybody here have a copy of the boot code disk for the B&K 2012 analyser?

My unit has lost its memory after some years in storage.

The hardware is in good shape.

Any help would be appreciated.

Please contact me off list

Pete
G4GJL

Thank you for the information. I will look into GOTEK. I think that is the easiest option.
thank you David !

Hi:
I am using CT-71 currently!
I may take some pictures for your references.
Rd
Tony Cheung
Feb 3 2025
从我的颈笔丑辞苍别传送

Annoyingly, any CT-71 test fixture seems impossible to find.

On Sun, 2 Feb 2025, 23:04 Sam Reaves via groups.io, <sam.reaves=
[email protected]> wrote:

Hello,

I am looking for the TO-66/TO-3 combination test fixture for the
Telequipment CT-71 Semiconductor Curve Tracer.

If I can't find one I would also like to have internal and external
pictures of one so I can make one. The pictures I have found on-line are
inadequate and the schematic
in the manual does not show either of the two fixtures that came with the
unit. I do have the TO-5 fixture and note that there are componets under
the bottom cover of the
fixure so I suspect tha the TO-66/TO-3 fixture may be similar.

The Tek part number for the fixture is:

013-0119-00

Thank you very much,

Sam
W3OHM

Nice lot Bill. Makes me wish that I had a need. Just want to remind you (and everyone) of the test equipment for sale group as well as this one.

pac1085 beat me to it . . . use the MT200 --> TO-3P adapter and new output devices.

Hello,

I am looking for the TO-66/TO-3 combination test fixture for the Telequipment CT-71 Semiconductor Curve Tracer.

If I can't find one I would also like to have internal and external pictures of one so I can make one. The pictures I have found on-line are inadequate and the schematic
in the manual does not show either of the two fixtures that came with the unit. I do have the TO-5 fixture and note that there are componets under the bottom cover of the
fixure so I suspect tha the TO-66/TO-3 fixture may be similar.

The Tek part number for the fixture is:

013-0119-00

Thank you very much,

Sam
W3OHM