开云体育

On Jun 18, 2018, at 8:13 PM, toby@... wrote:

no interest in
replacing the bulb with LED?

-----Original Message-----
From: Fabio Trevisan Sent: Monday, June 18, 2018 4:31 PM

Hello guys,
I wasn't sure if I should post it as an answer to a previous topic on
this previously discussed subject, or if I should start a new one...
And since this is not a question, but an informative message, I decided
for adding it as a new topic.

I successfully relabeled some of my Tek 464 push-button labels using a
reinvented and/or adapted technique of heat transferring a laser
printed text from temporary printed medium.

1. I started from the indication by the group of the correct font:
Univers Condensed and went on to search for a freely available TTF font
of such (and found one, which I uploaded to the Tekscopes Files (all
links further down).
2. Then I printed a sample sheet of paper and visually compared the
result to the original buttons.
3. Found the best results to be the mentioned font, in Bold, at 7pt
height, with 90% horizontal scale (shrunk horizontally to 90% of
nominal width), 4. Created a Word file (sorry MS-Haters... it was the
first thing at hand) with all the vertically oriented buttons (the
majority) of the 464.
Horizontally oriented buttons or other Tek scopes buttons are yet
to be made. Contributions are welcome.
6. Printed the file to PDF, using CutePDF writer and used the "Mirrored
Output" option from the Advanced -> PostScript options.
7. Peeled off all the labels from any label sheet at hand (think of
Avery or the equivalent to you).
8. Printed the PDF file without any scaling, to a laser printer, to
print on the non-sticking side of the label sheet (labels peeled off).
-> The result is a very finely printed labels, that lifts very easily
from the supporting paper... Care in handling from this point on.
9. Used an x-acto cutter knife to cut a cross-shaped around every
label, as illustrated on the pictures that I posted on the Photos
section (all links further down).
10. Wrapped the labels around the buttons and held them with adhesive
tape on the button sides. Don't let the adhesive tape crossover into
the button face. Keep them on the sides.
11. Heat transferred the labels to the buttons using a pressing iron
set at mid-high temperature (used an water steaming pressing iron to
ensure it doesn't get too hot), applying gentle pressure with the tip
of the iron, in sliding movements, for about 5 seconds.

Here are the files that I used, including the font (I got it as a free
font... I can't tell for sure if it's copyright free):
/g/TekScopes/files/Tek%20push-
button%20lettering%20using%20pressing%20iron%20transfer%20of%20laser%20
printed%20text%20on%20non-sticking%20paper

Here are the pictures of the process, before and after.
/g/TekScopes/album?id=60161

You will notice the first set of buttons (the vertical mode buttons)
are not just relabeled but whitened as well...(removed the yellowish
stain) That has nothing to do with the re-labeling itself... On the
first button I did, the CH1, the Iron was out of water and got too hot
(I didn't notice before it was too late)... The excess heat left an
even darker yellowish tint (almost brown) on the button and I had to
sand it off (fine grit 600, then 1200, then car polish).
Since it would become too distinct from the others, I decided to do the
same sanding to all the vertical mode buttons.
On the second group of buttons (horizontal mode), I only applied the
label to one of them... I dare you to spot which one.

KRgrds,

Fabio

Hi Dieter,

Thanks to Fabio's detailed and clever reasoning (you're very gifted Fabio), I
have found the issue with the Alt mode. The problem turned out to be a
defective U4391 (74LS02) that can be found on diagram 8 (Horizontal Display
Logic A&B Sweep Generator). When measuring pin 3 on this IC there was no
change in state (stayed low) when operating the ALT button in the "Horiz
display" section on the front control panel (after checking the switch first).
Replacing this IC from a butchered 465B restored the Alt mode and the scope
now reliably displays two traces :)

Note that your problem might be caused by a different component failure or
break in the Vert Alt Sync path, but if you follow Fabio's excellent
diagnostics, you will find the problem. Good luck, and another big THANKS to
Fabio, I owe you a drink!

Regards,

Edward Thomas.

Thanks Albert, you are of course right that I don't have a good grasp of even
the basics. Your posts do help. But I've had enough of this project.

I didn't even want a 465- I wanted a 465B but haven't been able to find one
locally and hesitate to buy one online. If anyone here on the forum can sell
me a good working 465B within a few hours driving distance of Louisville KY
then please PM me.

I will mention that a few years ago Albert, Raymond, David Hess, Ed B., Tom
Miller, Hank, and a few others did help me fix the 465B I had at that time- it
too was a long drawn out discussion, but ultimately together we got it working
and I used it for a few years until I lost everything in my divorce...

Thanks for everyone’s help, this is really a friendly and fascinating group.
At some point in the near future I will post for selling or parting out the
465 and the 464.

Keith Ostertag

From: "machineguy59 via Groups.Io" <machineguy59@...>

Menahem,
Any slight offense is in the past, lets go forward. ?

My goal here is to "first do no harm" then to payback for the help I have received from others.? I don't usually speak up right away, instead giving time for more experienced scope technicians to lead the way.? But I am very experienced with a wide technical base.? Like you I repaired radios and TVs (in the 1960's for me) and was appalled at the corners some manufacturers took to save a few cents.? After graduation from college (1963), I worked for the old Bell Telephone Laboratory, then Collins Radio (both quality minded, high technology organizations).? During my career I worked on the Nike anti-missile system, the first GPS receivers, auto-pilots, cockpit flight instruments, and many other avionics products.? I sometimes consulted for Rockwell International on computer matters.? If you ever ride in a Boeing airplane your pilot uses instrument displays done by the organization I lead.? The Tektronix 24xx series of oscilloscope was everywhere during those working years.? Often even in the conference rooms.? At one time, as Director of Engineering for Air Transport, I authorized purchase of 75 of them in one year.? I tell this story to better introduce myself and to validate my statement that I, too, seek quality in our work.

I think your goals for a perfect (or near perfect) BOM are admirable and I encourage you to lead that effort.? I will contribute when able and when my contributions are helpful.? But perhaps we should consider that some users are unable to source all parts or from all vendors.? At one time, the list I posted included part numbers from Mouser as well as Digikey so they could be ordered form either.? But it was tedious to keep up, especially when some parts are not available from both vendors.? And my goals do not prevent part substitutions when the perfect part is difficult to source.

Finally, what capacitors do you advise to use on the 24x5B A5 board?? I am now repairing my second one and need to make choices for at least the electrolytics.? Both boards I have are missing pads from missing electrolyte leakage.? I clean the boards and replace the pads.? But if I replace the capacitors with electrolytic caps it is certain they will fail one day and it is certain they will further damage the board and my replacement pads are not as robust as the originals.? I see one seller of rebuilt A5 boards uses tantalum electrolytics.? But tantalums are notorious for failure unless significantly de-rated for voltage.? For now I have used electrolytics but have started a plan to change them out for tantalums, derated 2:1 or more.?
? ??
On ?Monday?, ?June? ?18?, ?2018? ?01?:?54?:?55? ?AM? ?CDT, M Yachad <yachadm@...> wrote:

Hey Ron

Nice to get to know you! Thanks for telling us your story.
I understand your dilemma with your wife - we all empathize, even if we won't admit it as candidly as you did ;-)

I had no intention to deprecate, even if if it came across that way, and if I offended you, please accept my apology.

My purpose here is to build an iron-clad 2465 BoM, which will offer ALL users (experienced or not) an optimal long-lasting solution which will not require subsequent intervention under the cover again in our lifetimes.
In short, bringing together ALL our combined knowledge to provide an expert community solution.

I would not be writing all this, if it was not for all your help, because 9 years ago, when I started out on this journey and overhauled my own 2465B, I had no idea where to start, or which parts to select. All I knew was audio and linear PSU's. Only by asking these questions on this forum, was I able to get the info I needed, to do this once-only-required overhaul.

Today, SMPS overhaul (especially in TV's) is a substantial part of my workload, and I have built up my knowledge base substantially, regarding which component types are suited best in which areas of the circuit. I normally go through a few hundred capacitors every month, in these repairs.
So, I bring that acquired knowledge back to the forum, as a form of gratitude.

9 years later, the 2465B is still operating flawlessly, except for 2 problems (unrelated to the overhaul) - U700 failure, and a diode failure.
Solved quickly and painlessly, with the help of the generous people here.

I expect to pass all my lab equipment onto my middle son, aged 17, who is the only one of my 4 children who shows any serious interest in my work. With the maintenance I do on my equipment, I expect it to last 30 years for him as well.

Regarding suppliers, when approaching a project like this, I have learnt to not skimp, and if I have to source the optimal BoM from more than one supplier, then the small additional shipping cost (from the 2nd supplier) is peanuts, when figuring in the 20-30-year lifetime of a job done perfectly, not requiring any redo's in the future.

I use both Mouser and Digikey, but for the 2465 kits, Mouser offers me the parts I want, and also cheaper than Digikey by a few $ for this particular selection. So that extra $1 which you may pay Mouser for shipping, you'll probably save on individual parts costs.

Ancel,
I have used Nichicon PJ in the past as well - I have no aversion to them at all - and I normally use Nichicon PW (a tighter-tolerance brother of PJ) as my #1 choice.
That preference was based entirely on the datasheet specs, I did no comparison testing at all.

Menahem