Date   

Re: Question on what to do with 4 pallets of scopes...

keithostertag <keitho@...>
 

Oh boy, this is gonna be a fun thread!

My suggestion: find worthy/interesting persons/causes and start giving them away a few pieces at a time. You don't _need_ the money, and think about all the good will you will be spreading and interesting people you will meet (and possibly help/teach). Random acts of kindness- can't get better than that.

Keith Ostertag


Re: A Way to (Sometimes) Repair Broken 22xx Knobs

Philip McIntosh
 

So you mean you just blob on a small dab and push it on wet so it molds to the shape of the insert? Neat trick.

Phil...
*****

--- In TekScopes@..., "Tom Miller" <tmiller11147@...> wrote:

I use RTV sillycone. Just a dab in the bottom of the knob then push it on. Let cure for a day and you are all set. Benefit is you can still pull the knob off in the future.


Re: 2456B whole display moved up on the CRT

allegretto2a
 

Bob,
I does effect all 4 channels.  I hope it's not the hybrid!
Thanks, AL


--- On Sun, 2/17/13, Bob Koller wrote:

From: Bob Koller
Subject: Re: [TekScopes] 2456B whole display moved up on the CRT
To: "TekScopes@..."
Date: Sunday, February 17, 2013, 7:14 AM

 

Does this affect all four channels? If so, I would suspect a problem in the vertical output, perhaps as simple as one of the CRT neck leads ha come off, or something in the vertical chain has failed. Channel switch or vertical output hybrid.



From: allegretto2a
To: TekScopes@...
Sent: Saturday, February 16, 2013 8:17 PM
Subject: [TekScopes] 2456B whole display moved up on the CRT

 
My trusty 2465B now has a vertically offset display on the CRT. The bottom of the normal display is now at mid-point. Has anyone seen and solved this problem? Where do I look for the source of this problem?
Thanks, AL




Surplus outfits in Philladephia, PA (USA)?

Daniel Koller
 

Hi folks,

  Just a random question in the event there is an affirmative answer:  Does anyone know if there are any good electronics surplus stores in the Philladelphia, PA area (USA) where one might be able to pick up old Tek Scopes or HP test instruments?  Just curious, as I might have an opportunity to check it out.

  Has e-bay put all of these places out of business?  Surely there must be *some* brick-and-mortar warehouses left, no?

  Dan


Question on what to do with 4 pallets of scopes...

Chuck Harris <cfharris@...>
 

Here's the thing:

I have 4 pallets of tektronix scopes taking up space in my
warehouse. One pallet is mostly 7000 series, with a few
5000 series mainframes, another is a mix of 7000 and 5000
series rack mount scopes, with a 564. The third is mostly
453's, 454's, and a few odd 434, 464, 465, 466, 475, and 485's.
And the fourth has a 585A, 545A, and 535A on it... the '45
and '35 were beautiful before the tube whores stripped them...
but recycler's don't get the luxury of judging, they just take
what they get.... ixed in with all of this are several large
boxes of plugins... nothing sexy, but the usual 7B53A's, and
7A16, 7A26, 7D14, kind of stuff...

I love cleaning, fixing, calibrating and restoring scopes
into good working condition. I have all of the Tek specified
gear for doing this, but judging by ebay sales, buyers don't
seem to value that effort at all.

To give you an example. I found a DOA 434 in my stash, and
because it was so cute, I cleaned it up, fixed a power supply
problem that stumped the original owner, replaced a tantalum
on one of the boards, fixed a really nasty trigger problem,
that was caused by the power supply problem, lubed all of the
pots, cleaned and lubed the panel switches, and fan, cleaned
the attenuator contacts, and did a complete calibration. It
took me a week of evenings to do the work. When it was put on
ebay, as cleaned, calibrated, and guaranteed, it got a couple
of $15 offers, and it remains unsold... as does its twin that
I did in hopes of a better result...

At current US scrap prices, I can get $17 per pound for gold
plated circuit boards, which is the standard price recyclers
are giving these days... I work with a recycler, so I am very
sure of these prices... There is easily 2 pounds of circuit
boards in a 434 [vertical, horizontal, storage, preamps, and
power supply are all gold plated]. The 453's and 454's have
easily 5x more...

Considering how much you folks are yipping and yapping about
tunnel diodes, and how hard they are to find, I could have
gotten more than $15 if I simply removed the two diodes in
this 434, and sold them on ebay. And I would still have a
good CRT, the aluminum from the chassis and can, the gold
plated circuit boards, a bunch of special IC's, etc... I have
gotten $5 just from a knob, and $15 from just selling one CRT
filter!.... to sell.

What's the answer? I keep hearing about how much you guys
love Tektronix and their scopes, but when one sells for less
than a tankful of gas, I have to wonder if it is all just
dreamy nostalgia talk. When a couple of days worth of cleaning,
repairing, and calibration is worth less than you would pay
for a dinner out with someone you don't even like all that
much... Where is the love?

What's it to be? Do I fix them, or Do I scrap them?

What shall I do with these scopes?

-Chuck Harris


Re: A Way to (Sometimes) Repair Broken 22xx Knobs

 

I'll check that out. Thanks.
 
Tom
 

----- Original Message -----
From: Jim
Sent: Sunday, February 17, 2013 12:17 PM
Subject: Re: [TekScopes] Re: A Way to (Sometimes) Repair Broken 22xx Knobs

 

I've used E6000, a soft vinyl-based adhesive, with good success on re-gluing buttons.

I'm not sure which I prefer, clear silicone or E6000.  You should have some iof both in your kit.

73
Jim N6OTQ


From: Tom Miller <tmiller11147@...>
To: TekScopes@...
Sent: Sunday, February 17, 2013 11:15 AM
Subject: Re: [TekScopes] Re: A Way to (Sometimes) Repair Broken 22xx Knobs

I use RTV sillycone. Just a dab in the bottom of the knob then push it on. Let cure for a day and you are all set. Benefit is you can still pull the knob off in the future.
 
 
Regards,
Tom


Re: A Way to (Sometimes) Repair Broken 22xx Knobs

Jim <n6otq@...>
 

I've used E6000, a soft vinyl-based adhesive, with good success on re-gluing buttons.

I'm not sure which I prefer, clear silicone or E6000.  You should have some iof both in your kit.

73
Jim N6OTQ


From: Tom Miller
To: TekScopes@...
Sent: Sunday, February 17, 2013 11:15 AM
Subject: Re: [TekScopes] Re: A Way to (Sometimes) Repair Broken 22xx Knobs

I use RTV sillycone. Just a dab in the bottom of the knob then push it on. Let cure for a day and you are all set. Benefit is you can still pull the knob off in the future.
 
 
Regards,
Tom


Re: A Way to (Sometimes) Repair Broken 22xx Knobs

ROLYNN PRECHTL K7DFW
 

I tried super glue. Maybe my superglue is too old or something, but it just snapped right back off
again.

===============================

Try giving them a long rest before replacement to assure the full cure. I usually set them aside
and give them 24 hours. Haven't had a failure yet.


Rolynn


Re: A Way to (Sometimes) Repair Broken 22xx Knobs

 

I use RTV sillycone. Just a dab in the bottom of the knob then push it on. Let cure for a day and you are all set. Benefit is you can still pull the knob off in the future.
 
 
Regards,
Tom
 
 

----- Original Message -----
From: Philip
Sent: Sunday, February 17, 2013 12:07 PM
Subject: [TekScopes] Re: A Way to (Sometimes) Repair Broken 22xx Knobs

 

I tried super glue. Maybe my superglue is too old or something, but it just snapped right back off again. That is why I looked for a method that allowed for more flexibility and less rigidity.

Phil...
*****

--- In TekScopes@..., "ROLYNN PRECHTL K7DFW" wrote:
>
>
> What generally happens is one side of the little plastic retainer clip on the inside snaps off.
>
> =================================
>
> And a drop of Super Glue will fix the broken piece back into position.
>
> Fixed-done.
>
>
>
> Rolynn
>


Re: A Way to (Sometimes) Repair Broken 22xx Knobs

Philip McIntosh
 

Great tip. I thought of that but was not too sure about hitting the front panel with a hot air gun. Since I do have a hot air station with adjustable temperature, I will try that. Thanks!

Phil...
******

--- In TekScopes@..., "Tom Miller" <tmiller11147@...> wrote:

Hello Philip,

Please let me add to your comment a way to remove the knob caps that I find works.

As you say, they are old and brittle and prone to having the clips break off when pulled off. I take a hot air (de)soldering gun and use it to heat the knob enough to make it somewhat soft...


Re: TDS 744A Power Supply Issue - Any Ideas?

Andy
 

I can tell you from experience with switching power supplies that even replacing the fuse with the correct rating can cause more collateral damage if the power supply isn't fully repaired. Doubling the rating can lead to irreparable damage. If anything, I like to halve the fuse rating for the first test.

I would check/replace everything on the gate of that FET the blew up, and any other power transistors that have failed. If there are any ICs controlling that part of the power supply, replace them. Improper gate/base drive can cause instant failure. Also, loss of regulation can cause some spectacular failures.

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

I used the fused circuit of the meter (10A) which is a little over 2x max current.

--- In TekScopes@..., larrys@ wrote:

"circuitsandcode" <circuitsandcode@> wrote:
Would prefer to have a variable P/S to ramp up voltage - but went for
broke and shorted across the fuse (using multimeter measuring amps)
and Q5 went out in flames. I've since ordered a handful of 2SK1018
parts to replace.
Might want to make sure the meter didn't take any collateral damage.
-ls-


Re: A Way to (Sometimes) Repair Broken 22xx Knobs

Philip McIntosh
 

I tried super glue. Maybe my superglue is too old or something, but it just snapped right back off again. That is why I looked for a method that allowed for more flexibility and less rigidity.

Phil...
*****

--- In TekScopes@..., "ROLYNN PRECHTL K7DFW" <k7dfw@...> wrote:


What generally happens is one side of the little plastic retainer clip on the inside snaps off.

=================================

And a drop of Super Glue will fix the broken piece back into position.

Fixed-done.



Rolynn


Re: A Way to (Sometimes) Repair Broken 22xx Knobs

ROLYNN PRECHTL K7DFW
 

What generally happens is one side of the little plastic retainer clip on the inside snaps off.

=================================

And a drop of Super Glue will fix the broken piece back into position.

Fixed-done.



Rolynn


Re: A Way to (Sometimes) Repair Broken 22xx Knobs

 

Hello Philip,
 
Please let me add to your comment a way to remove the knob caps that I find works.
 
As you say, they are old and brittle and prone to having the clips break off when pulled off. I take a hot air (de)soldering gun and use it to heat the knob enough to make it somewhat soft. Then I use a long pair of needle nose pliers to slip under the knob where I can pop it off easily. You will need to find the proper amount of heat to get this to work. I set mine up for 120 °C with the smallest nozzle that came with the gun (about 1/4 inch dia).
 
HTH,
Tom
 
 
 
 

----- Original Message -----
From: Philip
Sent: Sunday, February 17, 2013 11:46 AM
Subject: [TekScopes] A Way to (Sometimes) Repair Broken 22xx Knobs

 

Well here is my first actual contribution to the group. I had to learn the hard way what most of you probably already know--NEVER REMOVE THE KNOBS FROM A 2200 SERIES SCOPE UNLESS YOU ABSOLUTELY HAVE TO.

I figured it would be easier to clean the front panel with the knobs removed (and it is) but I have experienced about a 50% breakage rate when removing the small knobs along the top and for the trigger. They are old and brittle. As has been pointed out, they are hard to find and not cheap when you do find them (although I was fortunate enough to talk a guy on eBay into selling me a lot of them for a pretty reasonable price).

So, I have been experimenting with ways to rescue the broken ones. What generally happens is one side of the little plastic retainer clip on the inside snaps off. One thing I have tried is drilling out an HP knob that looks exactly the same and figuring out how to secure it (these are available by the bushel for cheap at a local surplus store). No luck on that so far, but that is for another time.

What does mostly work is cutting a little piece of plastic tubing in the shape of the missing piece and sliding it into position with tweezers. It works best if the clip is completely broken off flush, but that is rare, so you have to cut the tubing to account for what ever part of the clip remains. The tubing I use is the flexible, clear plastic polyethylene Tygon type with an OD of 5/16in and a wall thickness of 1/64in.

They seem to pop back on pretty well. There is ever so slight an eccentricity when they turn but you'd really have to know what you were looking for to notice it.

I think it might even work better if the entire clip was missing and you might try removing it with a small grinding tool. Trying to break off the clip or remaining pieces has resulted in complete destruction of the knob. Let me know if you come up with any improvements or better ways to rescue a knob.


Re: A Way to (Sometimes) Repair Broken 22xx Knobs

DaveC <davec2468@...>
 

A photo would be great.

Dave

Sent from my iPhone

On Feb 17, 2013, at 8:46 AM, "Philip" <ndpmcintosh@...> wrote:

Well here is my first actual contribution to the group. I had to learn the hard way what most of you probably already know--NEVER REMOVE THE KNOBS FROM A 2200 SERIES SCOPE UNLESS YOU ABSOLUTELY HAVE TO.

I figured it would be easier to clean the front panel with the knobs removed (and it is) but I have experienced about a 50% breakage rate when removing the small knobs along the top and for the trigger. They are old and brittle. As has been pointed out, they are hard to find and not cheap when you do find them (although I was fortunate enough to talk a guy on eBay into selling me a lot of them for a pretty reasonable price).

So, I have been experimenting with ways to rescue the broken ones. What generally happens is one side of the little plastic retainer clip on the inside snaps off. One thing I have tried is drilling out an HP knob that looks exactly the same and figuring out how to secure it (these are available by the bushel for cheap at a local surplus store). No luck on that so far, but that is for another time.

What does mostly work is cutting a little piece of plastic tubing in the shape of the missing piece and sliding it into position with tweezers. It works best if the clip is completely broken off flush, but that is rare, so you have to cut the tubing to account for what ever part of the clip remains. The tubing I use is the flexible, clear plastic polyethylene Tygon type with an OD of 5/16in and a wall thickness of 1/64in.

They seem to pop back on pretty well. There is ever so slight an eccentricity when they turn but you'd really have to know what you were looking for to notice it.

I think it might even work better if the entire clip was missing and you might try removing it with a small grinding tool. Trying to break off the clip or remaining pieces has resulted in complete destruction of the knob. Let me know if you come up with any improvements or better ways to rescue a knob.



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

Yahoo! Groups Links



A Way to (Sometimes) Repair Broken 22xx Knobs

Philip McIntosh
 

Well here is my first actual contribution to the group. I had to learn the hard way what most of you probably already know--NEVER REMOVE THE KNOBS FROM A 2200 SERIES SCOPE UNLESS YOU ABSOLUTELY HAVE TO.

I figured it would be easier to clean the front panel with the knobs removed (and it is) but I have experienced about a 50% breakage rate when removing the small knobs along the top and for the trigger. They are old and brittle. As has been pointed out, they are hard to find and not cheap when you do find them (although I was fortunate enough to talk a guy on eBay into selling me a lot of them for a pretty reasonable price).

So, I have been experimenting with ways to rescue the broken ones. What generally happens is one side of the little plastic retainer clip on the inside snaps off. One thing I have tried is drilling out an HP knob that looks exactly the same and figuring out how to secure it (these are available by the bushel for cheap at a local surplus store). No luck on that so far, but that is for another time.

What does mostly work is cutting a little piece of plastic tubing in the shape of the missing piece and sliding it into position with tweezers. It works best if the clip is completely broken off flush, but that is rare, so you have to cut the tubing to account for what ever part of the clip remains. The tubing I use is the flexible, clear plastic polyethylene Tygon type with an OD of 5/16in and a wall thickness of 1/64in.

They seem to pop back on pretty well. There is ever so slight an eccentricity when they turn but you'd really have to know what you were looking for to notice it.

I think it might even work better if the entire clip was missing and you might try removing it with a small grinding tool. Trying to break off the clip or remaining pieces has resulted in complete destruction of the knob. Let me know if you come up with any improvements or better ways to rescue a knob.


Need TDS5000 series system restore CD

testtech <testtech@...>
 

Greetings Group,

I am in need of the System Restore CD for the TDS5000 (non B) series scope. The instrument I have has a failed HDD. Any help appreciated!


Re: 2456B whole display moved up on the CRT

Bob Koller <testtech@...>
 

Does this affect all four channels? If so, I would suspect a problem in the vertical output, perhaps as simple as one of the CRT neck leads ha come off, or something in the vertical chain has failed. Channel switch or vertical output hybrid.



From: allegretto2a
To: TekScopes@...
Sent: Saturday, February 16, 2013 8:17 PM
Subject: [TekScopes] 2456B whole display moved up on the CRT

 
My trusty 2465B now has a vertically offset display on the CRT. The bottom of the normal display is now at mid-point. Has anyone seen and solved this problem? Where do I look for the source of this problem?
Thanks, AL




465 Repair & Refurb on Hacked Gadgets

Bill Higdon
 


Re: Tektronix A6901 ground isolation monitor

PA4TIM
 

I tested it today, first it started beeping, so I turned the plug around ( in th US and UK with 3 pin plugs you can not do that so I suppose phase and zero are allway connected according a standard. Here we can plugin as we like, but this thing needs to be plugged in the right way. 

Then I connected a non grounded lightbulb. Turned the powerswitch, and pressed the right button and click, the ground fault breaker switched so I was in the dark. 

Then I removed the Termistor like you told and now I can power the lamp. I can do this in the grounded and isolated position ( tried an indtrument too). So that worked fine. 

I pushed the left red test button and I was in the dark again. Main groundfault breaker tripped a gain. Then I found a switch at the bottom that was in 5 mA. When I switch that to 0.5 mA and the 6901 in isolated position, pushing the button only switched of the load. So this is what I want. I now can probe in an isolated DUT but if I cause a short or there is a fault in the DUT the DUT switches off. Like when using the 1:1 transformer and series lightbulb.

If I use it in grounded position everything works but if I then push the left testbutton the main ground fault breaker still trips. But I think this is correct because that is what you want when using something grounded.

Hope you find some time to copy some manual pages. 

Thanks for the advise, i would not had found this myself without a circuit.

Slightly on-topic:

I have a 230-110V transformer with a red light on it. It has some error message written on it. It burns if the transformer is switched on, it goes out if the rail powers down. But it gave 15V and I use it whithou problems, so I thought the error was if the light went out,  I now tried the same thing and if I turn the plug the light goes out. But the strange thing is that when I switch of that powerrail ( a lot mains sockets on a row in groups with a switch at each group, like you use for lights) , the red light goes on again) it only switches one line so I think it noe switches the nul instead of phasel. I had an instrument that did the same. With power on the rail and the HP switched off, the powerlight was also off, but both switced off made the light glow dim. So I think I have to reverse those connections and use that transformer to test if all sockets ( about 50) are connected the same way. 

But i then still do not know if the instruments are connected the same way and if this matters. In a lot of countrys this seems to be important but not over here. Strange, there should be a reason or advantage ( noise or so ?) for that I guess. Otherwise why the light on the transformer and the test for this on the A6902. 

Fred PA4TIM

Op 14 feb. 2013 om 10:47 heeft "Craig Sawyers" <c.sawyers@...> het volgende geschreven:

 

> So if it does not start you should have a ground impedance problem ( or is it not the right test for modern groundfault breaker circuits ( those things in cabinet where your powerlines enter the house) i believe in old houses and some countrys they do not have them)

Correct - it is not compatible with precisely those. In "old" wiring, where there was a simple fuse-box there would be no problem. But in modern cabinets (ie any time in the last 30-odd years), it takes out the breaker. Turn the A6901 on and bang! Everything gets turned off.

> But if you have the manual, would you mind making a scan for me ? ( the operation part is most important)

This weekend is a possibility. What language? There are English, German, French, Spanish and Japanese operation sections. Service information is in English only.

Craig

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