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?

I think they should exist (different geometry) but have never found one - any members in Japan?

Regards,
David Partridge

-----Original Message-----
From: TekScopes@... [mailto:TekScopes@...] On Behalf Of Stefan Trethan
Sent: 26 October 2012 09:13
To: TekScopes@...

Subject: Re: [TekScopes] Re: Screwdriver for Pozidriv (Pozi) Screws used by Tek

Now that that's sorted, anyone willing to find out if there really is such a thing as a JIS screwdriver that is different to a philips?

ST

I looked one of the x-refs I have, and it lists the same RO board number for most 7K scopes,?with the exception of the 7704 (non-A), and the 7834.? I'm pretty sure that primary PCB?had at least one major ?layout change in it's many revisions,?because I recall?checking dissimilar boards to ensure the part numbers matched.

-Dave?

----- Original Message -----

From: "David" <davidwhess@...>
To: TekScopes@...
Sent: Thursday, October 25, 2012 6:20:29 AM
Subject: Re: [TekScopes] 7000 series on-screen displays boards

As far as I know, all of the 7000 series readout boards are
interchangeable. There was a late model readout board that used a
different design in the 7623B or 7633 but I suspect it will work as
well.

You might need to make or extend the coaxial lines and ribbon cables
if they are not long enough or even present. The frequencies involved
are not high so RG-174/RG-178 size coaxial cable will be more than
adequate as a replacement for the coaxial cable Tektronix used.

The N suffix plug-ins just lack the readout signal circuits. They
will work fine but will not generate a readout. Usually this was an
option but some plug-ins like the 7CT1N curve tracer never had readout
circuitry.

On Wed, 24 Oct 2012 23:53:22 -0400, Michael Dunn < md@... >
wrote:

My 7613 has no OSD board. Can these be found, and retrofitted?

Would a 7844 use the same board?

And do some plugins not work with that? (N suffix???)

thanks
Michael

I paid $2.00 + $2.25 shipping for one on Ebay. Now I'm kicking myself for waiting so long. This is definitely worth it. The one I bought (I have no affiliation with the seller) is called "GearWrench 80084 #1 x 3-1/8" Pozi Insulated Screwdriver". The seller has 362 of them at this 'Buy It Now' price so he is not likely to run out any time soon.

--- I had a 465 apart on the bench and I tried
the #1 screwdriver on every screw I saw on the 465 and it was the correct
size. The #2 screwdriver did not fit anything on the 465, nor did it seem
like a #0 screwdriver would be useful. I think the 7000 scopes have some
larger screws that might require the #2 Pozidriv, but that remains to be
seen.
tom jobe...

Crazy people... :oD

---
Enviado do meu Motorola PT550
Meu site:

----- Original Message -----
From: "Craig Sawyers" <c.sawyers@... <mailto:c.sawyers%40tech-enterprise.com>>
To: <TekScopes@... <mailto:TekScopes%40yahoogroups.com>>
Sent: Thursday, October 25, 2012 3:18 PM
Subject: RE: [TekScopes] Re: Estate sale scopes...

You made us look very hard for the Tek connection:

<>
<>
<>
<>
<>

I can just see it now. "I've bought a plane, dear" "You've done WHAT??"
"Yes - the good news is that it'll double up as a storage facility for the
test gear collection"

Craig

--------------------------------------------------------------------------------

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Thanks Jimmy, I am always very excited to hear from you (and from everyone else of course!)

Since my rudimentary Global Specialties 2001 function generator seems to be quite out of spec (according to my Fluke 87 III, recently calibrated) I decided I'd apply the 1kHz signal from the calibrator (It's not 500mV as specified in the manual but I thought it might stille give me something). Maybe I can somehow try getting a 500 mV 1kHz square wave from my SG and try again? As for the voltages I did check them for ripple and they all appeared to be fine (I did that with my Fluke) but a second thorough check sure is in order now. I'll do this tonight as well as checking the DC voltages around U445. It looks like the trigger board is going to have to go and I'll give the coupling and source switches a good cleaning.

As for the replacement of the electros do you recommend I get a vacuum desoldering gun (of the like of the Hakko 808) or would my low tech solder pump and whick would do the trick on a multilayer board? Somewhow I doubt it. I have seen that Radio Shack sells a cheapo soldering iron/solderpump combo that might just do the trick. Maybe I can try with this?

I'm going to have a nice chunk of time this weekend for experiments so I'll follow closely all your recommendations as usual and will get back to you with some (hopefully) positive results this time. Thanks again for all your help, I'm having so much fun :)

Cheers everyone,
Jerome.

--- In TekScopes@..., "jtjewell83" <jtjewell83@> wrote:

Jerome,

Did you apply the 1 kHz square wave to both Ext. Trigger inputs, like the manual says? If you did and you don't have a signal at pin 7 of each IC, I'd say you have a problem in one or more of the SOURCE or COUPLING switches (possible water damage maybe????). Oh, have you checked the +8 and -8 volt supplies at least at Q430A/R433 (+8V) and Q430B/R???-can't read schematic (-8V)?

Also, check the DC voltages around U445, if you haven't already. Some are on schematic (in the ovals).

I thought you had already check ripple on all the supplies, but I cannot remember for sure.

I had to replace the big electrolytic caps in one of my 468s. It's a job, but if done carefully, you'll get good results. Maybe about 8 hours total for me, including time spent to order the new caps. You do not have to remove the Interface Board to it, just the Trigger Board. Be carefull and try not to damage the pads/traces too much. And you'll need to add a few jumpers for the negative/can side of several of the caps. Plenty on that in the archives for 465, 475, 468. Make sure you get polarity right on each cap too!!! Post back if you're not sure about this.

Jimmy

--- In TekScopes@..., "jeromequelin" <jerome.quelin@> wrote:

Hello Jimmy and everyone else,

I finally have some time to give you a little summary of what I did. I followed Jimmy's advice and put together a sound card oscilloscope probe (even did an attenuator circuit for voltages above 1V) and probed a few test points on the A12 trigger board. Sadly on pin 7 of U240 and U445 I cannot seem to get a signal that makes any sense (nothing that the sound card scope can trigger on) and this lackluster signal doesn't seem to be a result of my very precarious probe because I could detect and trigger quite nicely on the 1kHz calibrator signal with it. I did set up the scope according to the manual (ext. trigger on both trigger A and B, AC coupled, external triggers...) but I could not make sense of what I observed on these two pins.

I did make two new observations:
1. whenever I probed U445 the scope triggered briefly, just like when I twiddled the slope switch. It happened every time I made contact with my sound card probe and every time I removed the probe.
2. This is a grim discovery : it looks like a couple of the large electro caps (C926 and C935 by the looks of it) from the main power supply have been releasing their corrosive guts and left a black trail around them... this is not good as I think I can't easily replace these guys... (and removing the A15 interface board on which they dwell seems like quite a production!)

All in all I think the sound card scope option just isn't going to cut the mustard. I am going to put this project on the side for maybe a month or until I can finally get hold of a functioning scope. In the meantime I'm going to start giving this little guy a good cleaning and maybe work on replacing these electros if at all possible!

Thanks so much for all your willingness to help me with my meager experience and scarce test equipment (I know this kind of long distance troubleshooting can be very frustrating for those helping!).

Jerome.

PS: I am located in the USA, near Princeton, NJ.

--- In TekScopes@..., "jtjewell83" <jtjewell83@> wrote:

Jerome,

I'm thinking you're going to need a scope to trace signals (unless you
get really lucky with your DMM!!!).

For a free PC sound card based scope, try this one:
<> . Make up a
simple cable that plugs into your sound card's line or mic input on one
end, and like a DMM probe tip (signal) and alligator clip (ground) on
the other. Then play with this with like some AA batteries, a 9-volt
battery, AC adapter with an AC output, etc., etc., to get comfortable
with this s/w. I'm thinking all or most sound cards have AC-coupled
inputs, so DC sources may not shown an indication when connected, except
maybe a quick spike. (I've never used this s/w much, just with the
internal mic in my laptop.) Hopefully, 9 volts DC won't damage the
average sound card's line or mic input. Maybe someone else in the group
knows of a better free PC sound card scope. I know there're others in
the TekScope archives.

Once you get that going and understand approximate peak-to-peak signal
levels, then start looking at what kind of signals you've got at pin 7
of U240 and U445 on the Trigger Gen. and Sweep Logic Board. Sheet 6,
A&B Tigger Generator. It looks like Q230A/B and Q430A/B have plenty of
drive capability (assuming they are good), so the sound card's Line
Input impedance shouldn't be a problem at these test points (44 and 41
respectively). Mainly concetration on U445, since that's for the A
sweep. The waveforms are just before the schematic. Let us know if you
do something like this, and we'll go from there.

If someone can think of something better for this situation, please feel
free to chime in.

Oh, what part of the world are you located? Maybe there's a group
member nearby that could help you.

Jimmy


--- In TekScopes@..., "jeromequelin" <jerome.quelin@>
wrote:

Yes I have but it won't trigger either. It looks like other than the
triggering issue the storage mode is fully functioning (the markers

seem

to work, the various display modes, norm, enveloppe, avg, seem to

behave

normally). I didn't have much time to work on it today but I read the
theory of operation some more and decided to start checking

transistors.

I checked Q119 (it's alright) whose emitter is used to generate the
trigger signal for ch1. Would you recommend that I start checking

every

transistor on the triggering board?
PS: I "fixed" the problem with ch1 and 2 traces being always on, a
problem I had created by mis-plugging a connector (P307)

Jerome.
--- In TekScopes@..., "jtjewell83" jtjewell83@ wrote:

Jerome,

Have you tried triggering while in storage mode?

Jimmy

I paid $2.00 + $2.25 shipping for one on Ebay. Now I???m kicking myself for waiting so long. This is definitely worth it. The one I bought (I have no affiliation with the seller) is called ???GearWrench 80084 #1 x 3-1/8" Pozi Insulated Screwdriver???. The seller has 362 of them at this ???Buy It Now??? price so he is not likely to run out any time soon.

Is the CRT shield in place? On my 7834, I had very similar symptoms
while the CRT shield was removed.

Be sure to check all of the low voltage supply voltage levels and
their ripple.

Does the Beam Find control have any effect? Could it be stuck on?

I would check the focus circuit. How did you measure the -2450
voltage?

Then I would work my way through the z-axis circuits.

On Thu, 25 Oct 2012 18:08:29 -0000, "james_young44" <jasyoung@...>
wrote:

Greetings,
I have recently joined this group in hopes of helping me keep my Tek scopes working in good shape. The best Tek I have is a 7603 with a pair of 7A18's and a 7B53A.

I also just bought a 475 portable scope because it's easier to tote around than the 7603. That was my thinking anyway.

However the 475 has a "no trace" issue, in that there is no trace evident under any normal circumstances. I followed the Troubleshooting chart in the maintenance manual and got so far as to have the leads to the deflection plates disconnected. Still no life on the screen, no central dot.

Using an abnormal setting of the focus and intensity, with a slow sweep rate, I get a fuzzy hint of a trace. Intensity fully CW, focus fully CCW with a 50ms sweep. This is with the deflection wires disconnected, sweep is line triggered, no vertical input.

The voltages on the bottom look fine with my DVM; the -2450V is good with a VOM. I have no way to test the HV.

I should look at the Z-axis amplifier? Are there problematic tantalums on there? What voltage should I see at the intensity grid on the CRT?

This scope is in very pretty cosmetic condition and it'd be nice if it would work. Thanks very much for any and all assistance.

Best regards,
Jim Young
Oberlin, OH

Hi looking for a suitable replacement for this diode.

I can cross this number to a 1N2609 but my sources have no stock.

Recomendations?

Thnaks, B

You made us look very hard for the Tek connection:

<>
<>
<>
<>
<>

I can just see it now. "I've bought a plane, dear" "You've done WHAT??"
"Yes - the good news is that it'll double up as a storage facility for the
test gear collection"

Craig