Re: Up to date capacitor list for Tek 2465A and 2465B scopes (2018)
Michael,
That sounds like a great idea. Is it reasonable to assume that a given part, like a 47uF 35V electrolytic, would have a single modern replacement recommendation? Or would it perhaps be necessary to use the Tek part number as the 'index' into the set of new part pages?
Either way, there could be a wiki page for each part, with notes associated with it like the ref-des for various models and any gotchas.
Then each model could have a list, by ref-des, of the parts that are candidates for replacement, with each line then clicking-through to the part page. The lists could perhaps even be partitioned into obvious areas like SMPS, PS, Vert, Trig, TB, etc. The only downside to this (general wiki pages) would be that it wouldn't be simple to get a BoM for the replacements for a model. That sort of stuff requires a more data base like back end I expect.
Cheers, Brian.
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Success!
Harvey White and machineguy59 - thank you so much for your prompt and insightful replies.
It was a transistor Q1062 that went bad (Base to Emitter open circuit failure) as R1071 was getting hot from over current (inverter drive circuit).
Replaced it and the squeaky "tick mode" came back. At first I had the original C1072 (3.3u/100v) replaced, although it had good capacitance and ESR (~3.2R) with an inferior chinese temporary replacement cap which blown after 10 sec...
So I reverted back to the original Nichicon (34 years!). Q1062 is a NPN transistor PN:151-0302-00 and the equivalent I used is 2N2222.
It's the 1st time I see this 2445 beautiful display and is so clear and steady and no faults/error codes displayed, nice readout clarity! what a joy resurrecting it!
After all that, I had another small but important issue: No Cooling
Fan not spinning, I measured supply 24V instead of 19.2V (15V unregulated) - I wondered is it too high??...
The fan doesn't spin, it's held in place by very strong magnetic force induced, at one time it did move a bit upon power up and stopped firmly,
only when unit powered down I can rotate the spindle easily with my fingers so I was thinking/testing:
Could the hall effect motor that this 2445 uses be faulty?
Could it be the fan board is getting to much voltage to make it stuck so hard?
I put 330uF/50V for C1116 at the rectifier section, could it be too much capacitance? (original is 180uF...)
The fan is temperature controlled and should be constantly spinning right? Or is the temp sensor that kicks in when temp is high and releases the motor shaft
The temp sense RT1696 reads 4.15Kohm at cold state and goes down to 1K after 15sec from power on, or from 24V to 7V. When does it kick in and moves the motor?
Finally - discovered U1690 IC (Quad transistor) which drives the motor 4 windings, had a faulty transistor: shorted Collector to Emitter (4 ohm) !
Under this IC pcb shows quite a blackening and probably suffered alot of heat trying to move a stuck motor.
This was probably one of the causes that made the faulty inverter capacitors fail from high temps over time (no air flow)...
Fortunately, the motor is still good and spins freely, all I did is replace U1690 (MPQ3725) with 4x 2N2222 transistors as suggested by Kibi on EEvblog:
{-thanks}
The temperature resistor also reacts nicely to temp changes and controls fan speed.
Now I'm waiting for a full cure of the squirrel-fan collet I glued together as I broke it, I hope it will work fine and hang nicely on to the motor shaft.
Thanks again guys.
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Re: Tek push-button lettering using pressing iron transfer of laser printed text on non-sticking paper
Hi Dennis,
Thanks for the heads up.
I didn't use any protection - YET - but I was planning to spray it on with protective varnish... of the kind that designers use to protect pencil drawn sketches.
But, I`m giving second thoughts as if it will be necessary at all... I explain why...
It took me quite more than a few trials to refine the process of how to properly center the labels on the buttons, as you can imagine.
The idea to cut the labels in that cross shape, with the cuts aligned to the outer contours of each label was, ultimately, what given me good reference lines that I could center about each button's corners...
In the process, I probably have done, and rejected, about 75% of all the labels I applied.
Every time I needed to redo one, i needed to scrape off the wrongly placed label and realized they became quite strong and scratch proof.
After the first or second I tried to scrape off gently, I gave up and decided to sand them out... and even sanding them, they wouldn't go away very easily.
I will leave it like that for some time and see how well they resist to time and use.
Rgrds,
Fabio
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On Mon, Jun 18, 2018 at 05:38 pm, Dennis Tillman W7PF wrote:
Hi Fabio,
Very nice idea and good documentation on how to do it. You didn't say what if
anything you put over the label to protect it after you transferred it to the
button.
Dennis Tillman W7PF
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Re: Tektronix 453 Power Indicator Bulb needed
At 10:13 PM 6/18/2018, Toby wrote: ... why is there no interest in replacing the bulb with LED? Probably because the lamps are cheap, easily available, and a lot less work. Dale H. Cook, GR/HP/Tek Collector, Roanoke/Lynchburg, VA
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Re: 576 Curve Tracer: Trace moving off screen and jittering when pressing CAL/Zero
I agree with Ed's diagnosis. The push button switches seem to be particularly vulnerable, and are a
bear to get to in order to squirt something like Deoxit into.
I took all the four main boards out, which meant that I could clean the cam switches too. This gives
access to the push button board. Squirt of deoxit and lots of pushing in and out cured it 100%.
The four boards have push on connections, so are easy to take out - just make sure the wires go back
in the right place!
Craig
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-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Ed Breya via Groups.Io
Sent: 19 June 2018 04:24
To: [email protected]
Subject: Re: [TekScopes] 576 Curve Tracer: Trace moving off screen and jittering when pressing
CAL/Zero
You have likely already found the problem - it's poor contact in the switches. Try working them
through all their states a lot (may take up to about a hundred times) and see if it settles down.
Also try
jiggling the buttons. If you can open it up enough to get some contact spray cleaner into them, that
would help a lot. This is a common problem with the 576.
Ed
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Re: 576 Curve Tracer: Trace moving off screen and jittering when pressing CAL/Zero
Okay looks like you're right. I guess some pins float that shouldn't when the switch doesn't make contact, causing odd behavior.
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Re: Tektronix 453 Power Indicator Bulb needed
T¡¯would be an easy proposition... if I need to replace one in my 453, that¡¯s what I will do.
Phil, N6OMM
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On Jun 18, 2018, at 8:13 PM, toby@... wrote:
no interest in
replacing the bulb with LED?
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Re: 576 Curve Tracer: Trace moving off screen and jittering when pressing CAL/Zero
I should say that I don't see the same behavior on the gates of Q531A/B, Q631A/B... I just see the switches being a bit flakey. I only see the exponential convergence on the source pins of these JFETs
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Re: 576 Curve Tracer: Trace moving off screen and jittering when pressing CAL/Zero
You have likely already found the problem - it's poor contact in the switches. Try working them through all their states a lot (may take up to about a hundred times) and see if it settles down. Also try jiggling the buttons. If you can open it up enough to get some contact spray cleaner into them, that would help a lot. This is a common problem with the 576.
Ed
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576 Curve Tracer: Trace moving off screen and jittering when pressing CAL/Zero
Hey all,
I'm trying to restore a 576 curve tracer. When I turn it on, the trace will go off screen... usually I'm able to move the trace back on screen using the position dials. However, when pressing the "invert", "zero", or "cal" buttons, the display will jitter quickly and then drift around, often settling off screen. I've traced the problem as far back as sources of Q531A/B and Q631A/B. What's curious is the drifting can appear independently on the vertical and horizontal. Sometimes both drift together. Sometimes one drifts. Sometimes the other drifts. The convergence to a steady value appears to be exponential with some jumps when observing the sources of Q531A/B and Q631A/B. The 100V supply and +/-12.5 V supplies seem steady, though reading off the decoupled 12.5 rails shows some twitching. Any ideas what could be going on?
Evan
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Re: Tektronix 453 Power Indicator Bulb needed
On 2018-06-18 5:38 PM, Michael Gladu via Groups.Io wrote: Thank you to everyone that took the time to reply to my message.
I had no idea that the bulb was in a bulb holder! I should have looked closer.
Thanks once again!
Pardon me if this is a dumb question, but why is there no interest in replacing the bulb with LED? --Toby 73 de N1FBZ
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Re: Tek push-button lettering using pressing iron transfer of laser printed text on non-sticking paper
Hi Fabio,
Very nice idea and good documentation on how to do it. You didn't say what if anything you put over the label to protect it after you transferred it to the button.
Dennis Tillman W7PF
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Show quoted text
-----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 -- Dennis Tillman W7PF TekScopes Moderator
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Re: Tek push-button lettering using pressing iron transfer of laser printed text on non-sticking paper
I've used the cold transfer method - it works a lot better than heat transfer for transferring images. There are many youtube videos on the method. The process can be used on just about any medium - wood, plastic, metal: Check out "TheCrafsman" - very cool and entertaining: Enjoy, JJ On Mon, Jun 18, 2018 at 7:31 PM, Fabio Trevisan <fabio.tr3visan@...> wrote: 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%20printed%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
|
Tek push-button lettering using pressing iron transfer of laser printed text on non-sticking paper
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%20printed%20text%20on%20non-sticking%20paperHere are the pictures of the process, before and after. /g/TekScopes/album?id=60161You 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
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OT: Looking for HP 334A H25 parts
Hi all. I will keep this short. Please respond to me off list.
I am looking for two feet 5060-0767 and tilt stand feet 1490-0030.
I¡¯ve searched on the inter web to no avail... if there is someone with extras, I¡¯d love to hear from you. Thanks!
Phil, N6OMM
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Re: Self Governance of TekScopes.
On Mon, Jun 18, 2018 at 12:57 pm, Dave Wise wrote:
It is perfectly acceptable to have unexpressed thoughts.
Dave Wise
______________________________________
Dave, Just ask any married man although not in the presence of his better half!! Jack
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Hello Edward,
Thanks for the update, and for the kind words... I think I was just in a good day.
In your case, I confess, when I jumped in I was believing the problem could be related to the ROM, only because I had a clear remembrance of reading about many incidents of ROM rots on some oscilloscope model(s) of that vintage.
But then, I decided to double check and learnt that that ROM in particular was not among the ones known to suffer from problems... AND ULTIMATELY, when I got to look a little bit more in detail to how the circuit worked, it wasn't that hard to see that it wasn't likely to be around the ROM chip, because the signal that tells ALT from CHOP doesn't even go into the ROM and doesn't matter to the operation of that circuit... and that was important to notice, because we knew CHOP was working.
Finally, to this particular control logic, if we rule-out the ROM and the LS175, and we also rule out a the Chop clock generator that we knew was working too... there was really very little left to get busy with.
Still, Dieter could have been right all along, because those Texas IC sockets are indeed awful.
They're particularly bad if the mating IC is one of the kind in which the pins are only tinned before the pins are cut-out to form the IC bonding spider (or whatever it's called in English).
On those ICs, the pin faces that were formerly the cross-section of the plate from which the pins are cut, are left exposed to the environment and ugly copper/brass oxides develop.
The evil in those Texas sockets is that they grab the pins exactly in that direction, that is prone to become badly oxidized (on the IC pin)... the IC socket contacts themselves are good quality gold-plated, but it's of little help if they contact the pins on the oxidized surface.
I`m glad that it worked,
Rgrds,
Fabio
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On Thu, Jun 14, 2018 at 01:53 am, <edward@...> wrote:
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.
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Re: Tektronix 453 Power Indicator Bulb needed
Thank you to everyone that took the time to reply to my message.
I had no idea that the bulb was in a bulb holder! I should have looked closer.
Thanks once again!
73 de N1FBZ
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Re: Tektronix 453 Power Indicator Bulb needed
Definitely Obtainium. Available at Mouser and Digikey for a dollar or two, and at BulbTown for fifty cents. Dave Wise ________________________________________ From: [email protected] < [email protected]> on behalf of ¸é±ð²Ô¨¦±ð <k6fsb.1@...> Sent: Monday, June 18, 2018 12:14 PM To: [email protected]Subject: Re: [TekScopes] Tektronix 453 Power Indicator Bulb needed according to TEK cross reference book page 15-4 (like pg 339 of 414 pages) bulb is #685,, 5V 60ma, 25K hrs .05 MSCP ¸é±ð²Ô¨¦±ð On 2018-06-18 12:03 PM, ROLYNN PRECHTL K7DFW wrote: I am looking for one B1107, 'Power On' indicator bulb, for the Tektronix 453 that I am trying to fix. The Tek part number is 150-0045-00. Does anyone have one that they would like to sell me or can anybody suggest a place to buy a replacement? The bulb appears to be a custom built bulb and may be pure un-obtainium.
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Re: Self Governance of TekScopes.
It is perfectly acceptable to have unexpressed thoughts. Dave Wise ________________________________________ From: [email protected] < [email protected]> on behalf of stefan_trethan <stefan_trethan@...> Sent: Monday, June 18, 2018 11:25 AM To: [email protected]Subject: Re: [TekScopes] Self Governance of TekScopes. No politics, no religion, no sports, simple as that. This has been the golden rule for groups for a long time, because it works. It doesn't matter how tempting it is to reply, how much a false statement cries out for correction, I must not reply. (And I intentionally write _I_ must not reply, because I am prone to off topic posting myself.) The sad truth is as much as we might agree on Tek scopes and technical topics in general, you'd be surprised how much we disagree on those three topics. Best not to find out. Forget all the other crap, forget off topic tangents or even the personal attacks (which happen quite rarely here, thankfully). That stuff just blows over by itself as people get bored or ashamed, but the big three have the real potential to break a group. The way I personally took Dennis's post was this: "Do not engage if you see something very off topic, no matter how much you want to". Admittedly this might be reading between the lines a bit, but if most of us just stick to that simple rule everything else will sort itself out. I was quite pleased with myself that I managed to delete my response to the Hiroshima post. ST
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Brian Cockburn
Fabio Trevisan
Dale H. Cook