Date   

Re: Lots of corrosion on my new (newly aquired) Type 576 Curve Tracer

Brent Watson <brentleew2003@...>
 

After a day of cleaning and lubing switches and contacts on the 576, it's not as bad as I thought. I used a small artists' brush and lightly coated a few circuit board  traces with DeOxit. Using De-ox on all the controls made a big difference. I was able to go through the familiarization procedure up to #51 with optimum results.Replaced a few rusted screws and went through initial test-set up  to #51 with optimum results.

Step 47 is the Step Generator.
After inserting an NPN transistor  and getting a minimum step amplitude, I can't get any steps.  I believe I saw some briefly yesterday, but can't get anything today. I got as far as putting my meter on  step generator IC U75 pins 9,1,3,5,  which respond to the "Number of Steps" switch. But have not been able to follow the path further.
I was hoping there might be someone here who knows these well enough to suggest where to suspect a problem. adapter doesn't support it, but didn't think it . I'm using an 013-069 adapter because that's what I have.  Here's a short video showing the issue.
https://www.youtube.com/watch?v=FdC9qWejY2M&feature=youtu.be


Cheers,
Brent

On Thursday, August 3, 2017, 12:29:15 AM PDT, 'Craig Sawyers' c.sawyers@tech-enterprise.com [TekScopes] <TekScopes@yahoogroups.com> wrote:

 
Mosyt instability is due to
the Display Invert and Display Offset Zero and Cal switched being super dryed out I checked
voltages
and ripple.
Is there any easy way to get at the controls for lubrication. I have the manual, but it looks
like you strip
the knobs and pull the front off.
It looks like I'll need a lot of contract cleaner. Perhaps a larger container of De-Ox.
The push button switches are notorious on the 576 and other instruments on which they are used. I
was lucky enough to get a 576 free from a guy who worked in the BBC Technical Centre in the UK. It
had a characteristic problem with the older 576 of epoxy potting on the HT transformer (yours is a
late instrument after Tek had gone across to silicone potting, so you're OK there). The BBC were
going to put it in the skip, so this guy hauled it home intending to fix it, never got around to it
and gifted it to me.

Anyhow, to cut a long story short, this 576 had had a really nice life in a dry air conditioned
environment. But the push switches were all intermittent.

To get to one set, you have to take out all some, or all horizontal and vertical boards. You have to
take the knobs off these and undo the switch securing nuts, then a screw at the back. You have to
unplug a great number of wires (use your phone to take lots of close up photos so you can put them
back correctly). If you have the manual there are clear diagrams which show which colour wires go
where too.

Once you get them out, you will see a board with the offending switches on it. Using the flexible
nozzle on a deoxit can you get a good squirt down the inside of each switch. Exercise each one a
lot, then a final squirt. Reassemble.

Good luck - these curve tracers are well worth saving!

Craig


Re: 2465A Filter, Implode shield, gray knob

mosaicmerc
 

Ok, will compare it to my 2465a shield for dimensions.


Re: 2465A Filter, Implode shield, gray knob

Tom Jobe <tomjobe@...>
 

The implosion shield is just another loose plastic piece behind the blue
or clear filter.
It's part number and physical dimensions may vary a little bit depending
on the serial number of your scope, so look at the parts list in the
back of your service manual in case it is like a plain 2465.
tom jobe...

On 8/4/2017 4:40 PM, mosaicmerc@yahoo.com [TekScopes] wrote:

Pulled the blue lens/filter & the knob. Anyone got advice on how to
pull the implode shield off a 2465?

[Non-text portions of this message have been removed]


Re: S52 pulse head standalone wiring/trigger? S4 for sale.

Ed Breya
 

One more thing - the S-52 output may appear rather strange due to the pattern of its operation. It's not a simple on/off pulse. Only one edge is the fast one of proper level. It occurs about 85 nSec after the pre-trigger pulse - the rest of the waveform may include various other levels, and should be ignored.

Ed


Re: S52 pulse head standalone wiring/trigger? S4 for sale.

Ed Breya
 

Get the manuals for it and the 7S12 - it should be clear and quite simple to set it up for stand-alone running. When properly powered up, the S-52 free-runs and provides a pre-trigger output.

Ed


Re: 1502 what's it worth?

Richard Solomon <dickw1ksz@...>
 

I paid $50 for one on e-Bay. Once I
added a big Cap to replace the dead
battery pack, it worked.

Cute toy, did actually use it, twice.

73, Dick, W1KSZ

On Fri, Aug 4, 2017 at 5:16 PM, tigrol.lechat@gmail.com [TekScopes] <
TekScopes@yahoogroups.com> wrote:



Hello all,

What is a Tek 1502 (no suffix) with X-Y output module worth these days?
How much should I offer for one in un-diagnosed non-working condition
accounting for most common faults?

Thanks.

Paul

[Non-text portions of this message have been removed]



[Non-text portions of this message have been removed]


1502 what's it worth?

 

Hello all,

What is a Tek 1502 (no suffix) with X-Y output module worth these days?
How much should I offer for one in un-diagnosed non-working condition accounting for most common faults?

Thanks.

Paul


2230 numerical readout error and power supply noise

John Brown
 

This 2230 seems to work OK (analog section - don't know about storage).


But the readout of volt/div is wrong on some settings; always going to the next higher reading according to the analog voltage level supplied by the voltage divider. In other words 2mV/div almost always reads .2V/div which is the next higher voltage range the divider provides to the digital section. 2mV measures 2.267V (which is within the proper range 2.104 to 2.340) but the readout displays .2V (which is the next range 2.340 to 2.502).


I at first thought it was the 4 finger contacts on the drum switch; but they measure good and consistent and the voltages out of the switches also measure good - well within the range listed for each setting.


Then I scoped the switch output and found a 20ish KHz spike very noisy about 20mV. My theory now is this spike is fooling the digital decoding. Yes?


Going to the power supply all the positive supplies have some level of the 20Khz noise. The negative supplies not so much.


The 100V supply has a 250mV spike. 30V supply a 50mV spike. I replaced both filter caps (C954 and C956) with no change. The 8.6V supply a 30mV and the 5V supply a 20mV. Replacing caps made no difference.


I will keep plugging away. All power supply measurement has been at the final filter cap for that supply (diagram 9)


Isn't this in fact way too much noise on the supplies? Whether or not the cause of the bad display readouts.


Thanks
John


Re: 2465A Filter, Implode shield, gray knob

mosaicmerc
 

Pulled the blue lens/filter and the knob, CRT shield looks a bit trickier, never pulled one.
Anyone got any advice on extracting that from a 2465?


Re: 2465A Filter, Implode shield, gray knob

mosaicmerc
 

Pulled the blue lens/filter & the knob. Anyone got advice on how to pull the implode shield off a 2465?


S52 pulse head standalone wiring/trigger? S4 for sale.

mosaicmerc
 

Hi All:
I picked up a 17 psec S52 from EBAY and I am trying to figure out the way to power it up and give it a trigger.

Can anyone point me in the right direction please?




Also, got an S4 sampler in near mint condition (package deal) if anyone needs one before I put it back on EBay.


Re: Tektronix 454

erik erickson
 

The trace doesn't appear at all on channel 2. I got it to come up a few times but not lately and I don't remember what i did. And a couple times I had the cover of it and it worked for a good 10 minutes but quits again.

Sent from my iPhone

On Aug 4, 2017, at 6:18 AM, David davidwhess@gmail.com [TekScopes] <TekScopes@yahoogroups.com> wrote:

I encourage you not to give up on your 454. It has a fabulously
bright and sharp CRT.

I have to ask some of the same questions:

1. Does the trace drift off screen when the input coupling is set to
ground?

2. Does the trace drift off screen when the input coupling is set to
DC and the input is shorted?

One thing that can cause the trace to drift off of the screen is if
the DC circuit path to the grid of V113 shown on schematic 2 is open.
This could include an open R110.

The variable control is R167 and could not cause the trace to drift
off of the CRT by itself.

What does the channel 2 INVERT switch do? It would cause problems if
the switch was bad.

Since only channel 2 is affected, the problem is on either schematic 2
or schematic 3 before the delay line driver.

On Tue, 1 Aug 2017 11:24:52 -0700, you wrote:

Hey I'm very sorry for taking so long to respond. I've been very busy at work and in going out of town soon. I reseated the transistors on the channel 2 vertical preamp. The trace most of the time isn't on the screen so I can't be sure. I haven't seen a trace on channel two in a while. Channel one seems to work fine. Only problem is the red knob on the volts/division doesn't work.

Sent from my iPhone

On Jul 21, 2017, at 8:03 PM, David davidwhess@gmail.com [TekScopes] <TekScopes@yahoogroups.com> wrote:

Which transistors did you reseat?

Does the trace drift off screen when the input coupling is set to
ground?

Does the input response normally while it is on screen?

On Wed, 19 Jul 2017 22:06:56 -0700, you wrote:


Hey everyone my tektronix 454 channel two doesn't work. It worked for about 20 seconds when I reseated all the transistors and then slowly went off the screen. Sometimes it works but will always stop working within 20 seconds. The position knob would not bring it back. I'm new to this so all help will be greatly appreciated. I have the manual and I've been reading it.
Sent from my iPhone

[Non-text portions of this message have been removed]


Re: Tektronix, Fluke now part of Fortive

Daniel Koller
 

In the end, there can be only one!
  Dan

On Friday, August 4, 2017, 1:30:43 PM EDT, Artek Manuals manuals@artekmanuals.com [TekScopes] <TekScopes@yahoogroups.com> wrote:

Since Keithly was was rolled up up under Tektronix after the acquisition
by Danaher ( in competition with their now "Step brother" Fluke)  I
wonder if that means they will finally roll the Keithly stuff over to
Fluke? Never understood why Danaher  didn't do that in the first place (
or maybe they already did)
Dave
manuals@artekmanuals.com?

On 8/4/2017 1:04 PM, Brad Thompson brad.thompson@valley.net [TekScopes]
wrote:
Hello--

This slipped past me:

http://www.fortive.com/news-events?page=0

...And Fluke and Tektronix are no longer part of Danaher.

73--

Brad  AA1IP


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

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


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

Yahoo Groups Links



--
Dave
Manuals@ArtekManuals.com
www.ArtekManuals.com


Re: Tektronix, Fluke now part of Fortive

Artek Manuals <manuals@...>
 

Since Keithly was was rolled up up under Tektronix after the acquisition by Danaher ( in competition with their now "Step brother" Fluke) I wonder if that means they will finally roll the Keithly stuff over to Fluke? Never understood why Danaher didn't do that in the first place ( or maybe they already did)
Dave
manuals@artekmanuals.com?

On 8/4/2017 1:04 PM, Brad Thompson brad.thompson@valley.net [TekScopes] wrote:
Hello--

This slipped past me:

http://www.fortive.com/news-events?page=0

...And Fluke and Tektronix are no longer part of Danaher.

73--

Brad AA1IP


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

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


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

Yahoo Groups Links



--
Dave
Manuals@ArtekManuals.com
www.ArtekManuals.com


Tektronix, Fluke now part of Fortive

Brad Thompson <brad.thompson@...>
 

Hello--

This slipped past me:

http://www.fortive.com/news-events?page=0

...And Fluke and Tektronix are no longer part of Danaher.

73--

Brad AA1IP


Re: Tektronix 454

 

I encourage you not to give up on your 454. It has a fabulously
bright and sharp CRT.

I have to ask some of the same questions:

1. Does the trace drift off screen when the input coupling is set to
ground?

2. Does the trace drift off screen when the input coupling is set to
DC and the input is shorted?

One thing that can cause the trace to drift off of the screen is if
the DC circuit path to the grid of V113 shown on schematic 2 is open.
This could include an open R110.

The variable control is R167 and could not cause the trace to drift
off of the CRT by itself.

What does the channel 2 INVERT switch do? It would cause problems if
the switch was bad.

Since only channel 2 is affected, the problem is on either schematic 2
or schematic 3 before the delay line driver.

On Tue, 1 Aug 2017 11:24:52 -0700, you wrote:

Hey I'm very sorry for taking so long to respond. I've been very busy at work and in going out of town soon. I reseated the transistors on the channel 2 vertical preamp. The trace most of the time isn't on the screen so I can't be sure. I haven't seen a trace on channel two in a while. Channel one seems to work fine. Only problem is the red knob on the volts/division doesn't work.

Sent from my iPhone

On Jul 21, 2017, at 8:03 PM, David davidwhess@gmail.com [TekScopes] <TekScopes@yahoogroups.com> wrote:

Which transistors did you reseat?

Does the trace drift off screen when the input coupling is set to
ground?

Does the input response normally while it is on screen?

On Wed, 19 Jul 2017 22:06:56 -0700, you wrote:


Hey everyone my tektronix 454 channel two doesn't work. It worked for about 20 seconds when I reseated all the transistors and then slowly went off the screen. Sometimes it works but will always stop working within 20 seconds. The position knob would not bring it back. I'm new to this so all help will be greatly appreciated. I have the manual and I've been reading it.
Sent from my iPhone


Re: New 547 owner

Don Lewis <dlewis11193@...>
 

Give it bath!
I've bee washing scopes (and all electronics)  for years.  The key is allowing time to dry. 
We've had over 30 days of 100+ degree temperatures in Texas this summer, ...so 'drying' has not been a real issue. 
I am currently refurbishing a 1951, RCA-WO56A scope, but at this age, most vacuum tube test equipment is similar to Teks and HPs.
What follows is my technique.  Certainly not sacrosanct, but works for me:
- Get documentation.
- Get documentation if you can that, as a minimum, lists the scope's specifications and tube types/placements.
- Remove the cover and inspect for loose objects, wires, tubes out-of-socket, etc.  Triage the unit.
- Make your own drawing of major items on the scope chassis and tube placement.
- Remove each tube individually. 
- Compare the tube marking to what is on the schematic and hopefully what is stenciled on the tube chassis. 
- Note whether they match or not. Document what they are/ where they are.
- Clean each tube carefully.  The markings on the tube are like old fingerprints.  They will unfortunately just dust away.
- Get a 'marks-on-glass' pen.
- Write on each tube its' type, if you can verify it.
- Store away all the tubes for now.
- Take the scope outside and protect the transformer opening the best you can with a plastic baggie, saran wrap. etc.
- I then douse the entire scope, top and undersides, with a complete bottle of dishwashing detergent.  Get it good and soapy.
- Then power-wash it with a hose and a hard stream of water.
- Get it good and soapy.
- All nooks and crannies, especially the tube sockets and switch wafers.
- Do not concentrate on the transformer areas or openings.
- Once washed, take a bottle of rubbing alcohol and pour over all the slide switches and rotary switches; work them through their positions.
- Not the potentiometers.
- Let it dry.  Let it dry thoroughly.
- The key is to let the entire scope dry for at least a week outside in the wind and sun.  Turn it once a day, ultimately through all dimensions, so no liquids are left in hidden pockets. 
- Be patient.  Don't try to cur corners in drying time in an oven, etc.
- Test the tubes.
- While the scope is drying, test the tubes.
- As a minimum, use an ohmmeter to test each tube for filament continuity.
- I have both a venerable Hickok 752A mutual conductance tester as well as a basic Mercury 990 cathode emission tester.
- Use whatever tester you have, but test the tubes.  
- Ensure the correct tube came from its' requisite socket.
- Tubes get replaced over 50-60 years.  Substitutions are made.
- Convince yourself the right tube is in the right socket and that it tests ok. 
- Don't worry right now about marginally-tested tubes.  If they have filaments and some life, they may very well work for the design they are in.
- Re-install the tubes after a week of chassis drying.
- Check for loose wires, components out-of sorts, etc.
- Continuity check the power, switch and fuse circuits. 
- If the scope uses a two-wire power cord, ohm it out for hot and neutral, and always plug it in accordingly (hot-to-hot; neutral-to-neutral) until you can rewire using a grounded power cord.
- Get a Variac. 
- Now we try to reform the old caps.
- I use a Variac through a voltmeter/ammeter to the scope power plug.
- Turn the scope on and apply the first increment of 20vac.
- I start with 20vac out of the Variac and watch the current. 
- Note from the scope specifications what the power and current requirements are.  Never let this reforming exceed these specifications.
- Of course, if it does, then it's time to troubleshoot.
- Continue on if the current out of the Variac hold to spec or less.
- Be patient.
- I take one full day at 20vac increments (each day).  Ultimately, reaching 120vac.
- If you get this far, you can start checking all voltages, ripple and subsequently scope performance and go to calibration.
- Note that this 'washing' process works quite well with modern scopes and even switching power supplies.  BUT DO NOT USE THE VARIAC.  Just turn it on once it is dry and monitor the ammeter.  If current is excessive, go to debug mode.

This probably could have been stated more eloquently, but I was just trying to help; get some thoughts down.  Good 'washing'

Don

N5CID




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

On ‎Wednesday‎, ‎August‎ ‎02‎, ‎2017‎ ‎11‎:‎10‎:‎47‎ ‎PM, matthew@splitred.com [TekScopes] <TekScopes@yahoogroups.com> wrote:

 
Chuck,

Thanks for your message.


I will resist the urge to make either a parts unit - my goal is to get the 547 up and running. If I can do that, the 546 may just sit for a while before I can get to it. Too many other pressing projects.


Not sure about giving it a shower - I'm afraid to do it! Though I do have a basement sauna that would probably work well to speed the drying process.


I'll look for your transformers and check voltages & ripple when I return in two weeks.


Thanks again!



Matthew

[Non-text portions of this message have been removed]


Re: I almost blew a cerebral artery

Brad Thompson <brad.thompson@...>
 

On 8/3/2017 5:48 PM, snapdiode@yahoo.com [TekScopes] wrote:
can you guess why?
http://www.ebay.ca/itm/A-G-Tannenbaum-Tektronix-2901-Time-Mark-Generator-Bound-Manual-Copy-/172680305380?hash=item28348c5ae4:g:S6sAAOSwhvFZHeFa http://www.ebay.ca/itm/A-G-Tannenbaum-Tektronix-2901-Time-Mark-Generator-Bound-Manual-Copy-/172680305380?hash=item28348c5ae4:g:S6sAAOSwhvFZHeFa
Hello--

"Tektronics"?? The odd font of the letter "S"? Is this a knockoff of a Tannenbaum original copy?

...Or am I experiencing post-dinner digestion-induced mental obtuseness and not
seeing what's before me?

73--

Brad AA1IP


Re: 2465A Filter, Implode shield, gray knob

Spike
 

Hi AncelB,

I don't need all those knobs though, I only need one gray one.

If you get busy or something let me know.

Thanks,


Re: I almost blew a cerebral artery

Fabio Trevisan
 

That's why we cheerish the Artek Manuals folks!

That"s almost a blasphemy...

Fabio

On Aug 3, 2017 6:51 PM, "snapdiode@yahoo.com [TekScopes]" <
TekScopes@yahoogroups.com> wrote:



can you guess why?

http://www.ebay.ca/itm/A-G-Tannenbaum-Tektronix-2901-
Time-Mark-Generator-Bound-Manual-Copy-/172680305380?hash=item28348c5ae4:g:
S6sAAOSwhvFZHeFa http://www.ebay.ca/itm/A-G-Tannenbaum-Tektronix-2901-
Time-Mark-Generator-Bound-Manual-Copy-/172680305380?hash=item28348c5ae4:g:
S6sAAOSwhvFZHeFa



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