Date   
Re: Tek 2465 Problem

Panos
 

Yeah maybe it's better to do so. Nevertheless I thought about making an effort, since after the calibration the oscilloscope is working properly, apart from this detail.
To be fair opposite to QService, the calibration cost did not include any minor repairs to the machine.

In the meantime as I looking the reason for this problem, I made some progress. As I check the waveforms around the U500-U700-U800 according to the service manual, I see some instabilities on the signal during the interference.

Specific from the Inverted A Trigger output of U500 pin 18 to Trigger In of U700 pin 2.
After the same from the ramp output of U700 pin 35 to the A Sweep Input of the U735 pin 9.
Finally the same from the U735 pin3 to U800 A Sweep Input pin18.

That gave me the idea to look before the U500 the the trigger level lines A and B. There in A5 digital board, is a double operational amplifier marked as TL072, which drive the A and B trigger lines to U500.
Measuring the amplifier input and output with a voltmeter, I was surprised by the very low voltage across the full range of the trigger level control knob. The measurement was lower than +/- 500 mVolt across the range and in the trigger status about 200 mVolt in line A, contrary to 2.5 volt and 600 mVolt of line B.

I replaced the TL072 operational amplifier and now things was improved! As for the level of the voltage during trigger moment came at the same level for both A and B lines. About 600 mVolt.
Although it seemed that the problem was completely solved, something strange appeared using a different type probe.
As a remind, the interference was appeared when the volt/div selector was in the range of 20 mVolt and below (200 in my case using a x10 probe).

But enough with the written. I have to make a video.

Re: telonics sweep generator

battyhugh
 

Thanks Dave - I'll try the eBay link first - where can I get the old style 3 pin plug?

Re: telonics sweep generator

battyhugh
 

Thanks for that - I'll chase up the link.

Re: Tek 2465 Problem

Harvey White
 

Some of the trigger settings have high pass or low pass filters, and can be sensitive to the frequency of the waveform.

Harvey

On 12/16/2019 2:58 PM, Panos wrote:
Hi Chuck,
Yes I have a problem about the trigger in the vertical amplitude in 200 mV and below, AC or DC input coupling at any horizontal timing setting. This will disappear only if I set Noise or HF Rejection coupling. On screen it look like a second sweep identical to the main sweep during the trigger in a signal. This happen at any of the two first input channels 1 or 2.

Initially I did not understand what exactly was the problem, because I was using the calibrator of oscilloscope with my x10 probe as a source.
So during the triggering I was seeing the upper and lower faces of the square wave sweep signal to roll like a straight line left or right on the screen.
I have checked the output of my calibrator on another (Protek) oscilloscope, and the trigger working perfect in all horizontal settings.

So I thought to feed the same amplitude signal 400mV p-p in my oscilloscope from my CFG253 external generator, using a sawtooth or sinewave signal at 1KHz.
Τhen the second waveform was clearly visible.
This second waveform will be moved left or right on screen using the trigger level, but never disappear except if I using the Noise or HF Rejection coupling setting.
It looks like it can't work correctly the trigger level, or better off having a poor trigger.

Maybe i will be better to do a video about this as you will better understand what I mean.

As a memo must I inform you that in this oscilloscope all the PSU capacitors have been replaced with alternate Nichicon type, and also have been calibrated before 15 days from QService.

Panos



Re: Tek 2465 Problem

Chuck Harris
 

If your scope was calibrated 15 days ago by Q-Service, you
need to get it back to them.

I have a suspicion that what you are describing is a retrace
problem (Z-Axis), but, I am having some trouble following your
meaning.

Whatever the problem, it should have been discovered when the
calibration was done.

-Chuck Harris

Panos wrote:

Hi Chuck,
Yes I have a problem about the trigger in the vertical amplitude in 200 mV and below, AC or DC input coupling at any horizontal timing setting. This will disappear only if I set Noise or HF Rejection coupling. On screen it look like a second sweep identical to the main sweep during the trigger in a signal. This happen at any of the two first input channels 1 or 2.

Initially I did not understand what exactly was the problem, because I was using the calibrator of oscilloscope with my x10 probe as a source.
So during the triggering I was seeing the upper and lower faces of the square wave sweep signal to roll like a straight line left or right on the screen.
I have checked the output of my calibrator on another (Protek) oscilloscope, and the trigger working perfect in all horizontal settings.

So I thought to feed the same amplitude signal 400mV p-p in my oscilloscope from my CFG253 external generator, using a sawtooth or sinewave signal at 1KHz.
Τhen the second waveform was clearly visible.
This second waveform will be moved left or right on screen using the trigger level, but never disappear except if I using the Noise or HF Rejection coupling setting.
It looks like it can't work correctly the trigger level, or better off having a poor trigger.

Maybe i will be better to do a video about this as you will better understand what I mean.

As a memo must I inform you that in this oscilloscope all the PSU capacitors have been replaced with alternate Nichicon type, and also have been calibrated before 15 days from QService.

Panos



Re: Tek 2465 Problem

Panos
 

Hi Chuck,
Yes I have a problem about the trigger in the vertical amplitude in 200 mV and below, AC or DC input coupling at any horizontal timing setting. This will disappear only if I set Noise or HF Rejection coupling. On screen it look like a second sweep identical to the main sweep during the trigger in a signal. This happen at any of the two first input channels 1 or 2.

Initially I did not understand what exactly was the problem, because I was using the calibrator of oscilloscope with my x10 probe as a source.
So during the triggering I was seeing the upper and lower faces of the square wave sweep signal to roll like a straight line left or right on the screen.
I have checked the output of my calibrator on another (Protek) oscilloscope, and the trigger working perfect in all horizontal settings.

So I thought to feed the same amplitude signal 400mV p-p in my oscilloscope from my CFG253 external generator, using a sawtooth or sinewave signal at 1KHz.
Τhen the second waveform was clearly visible.
This second waveform will be moved left or right on screen using the trigger level, but never disappear except if I using the Noise or HF Rejection coupling setting.
It looks like it can't work correctly the trigger level, or better off having a poor trigger.

Maybe i will be better to do a video about this as you will better understand what I mean.

As a memo must I inform you that in this oscilloscope all the PSU capacitors have been replaced with alternate Nichicon type, and also have been calibrated before 15 days from QService.

Panos

Re: 2465 manuals - which is considered best? most searchable? through? etc.

GerryR
 

I have the 2465A manuals, op and service, and can not find any of what Mr. Panos sited in his inquiry, as well. But the manual I have is accurate as applied to my 2465A 'scope.
GerryR
KK4GER

----- Original Message -----
From: "Lawrance A. Schneider" <llaassllaaass@...>
To: <TekScopes@groups.io>
Sent: Monday, December 16, 2019 2:06 PM
Subject: [TekScopes] 2465 manuals - which is considered best? most searchable? through? etc.


Below please find a list of my 2465 - 67 manuals. I have others, but what I want to know is how do they differ. i.e NOT ONE IS IDENTICAL TO ANOTHER. I know I can compare them in bbedit or vi and others, but that is not my point. When someone cites a specific section of the manual by page or whatever, to which manual are they referring?

Mr Harris referenced: CA3046 transistor arrays. I find no such reference. Mr. Panos cited: Waveforms 28 and 46 on pages 238 and 239 in service manual. These appears in diagram No 5 in page 244.

I don't have anything relative to waveforms on pages 238 nor 239 nor 244. I do find a pulse waveform adjacent an hexagonal 28 within labeled "AUTO W/NO TRIGGER" and again hexagonal 46 unlabeled but they are on page 424.

Here is my list:

2465B - 2467B portable oscilloscope service manual 070-6863-00 no search.pdf
2465B - 2467B text_searchable 070-6863-00 somewhat search.pdf
2465B & 2467B Oscilloscopes 070-6863-01 Service Manual
2465B options and operator manual.pdf
2465B_2467B
2465B_2467B_Service_1993 070-6863-01.pdf
2465B-2467B_HI_TEXT.pdf
2465B, 2455B, 2445B Oscilloscopes and options Operators Manual (May 88) the manual number70-6860-00
2467B Library_text searchable 070-6861-00.pdf
2467B Ops text searchable.pdf

As a group, do we have a source to which we refer? In my list you may notice the manual number such as: 070-6863-00 BUT!!! 070-6863-00 and 070-6863-01 are called Service Manual when you open either. You my note I added at the end of a line: searchable or no search. That is, some I can search for "waveforms" and others I cannot.

Thank you, larry

2465 manuals - which is considered best? most searchable? through? etc.

Lawrance A. Schneider
 

Below please find a list of my 2465 - 67 manuals. I have others, but what I want to know is how do they differ. i.e NOT ONE IS IDENTICAL TO ANOTHER. I know I can compare them in bbedit or vi and others, but that is not my point. When someone cites a specific section of the manual by page or whatever, to which manual are they referring?

Mr Harris referenced: CA3046 transistor arrays. I find no such reference. Mr. Panos cited: Waveforms 28 and 46 on pages 238 and 239 in service manual. These appears in diagram No 5 in page 244.

I don't have anything relative to waveforms on pages 238 nor 239 nor 244. I do find a pulse waveform adjacent an hexagonal 28 within labeled "AUTO W/NO TRIGGER" and again hexagonal 46 unlabeled but they are on page 424.

Here is my list:

2465B - 2467B portable oscilloscope service manual 070-6863-00 no search.pdf
2465B - 2467B text_searchable 070-6863-00 somewhat search.pdf
2465B & 2467B Oscilloscopes 070-6863-01 Service Manual
2465B options and operator manual.pdf
2465B_2467B
2465B_2467B_Service_1993 070-6863-01.pdf
2465B-2467B_HI_TEXT.pdf
2465B, 2455B, 2445B Oscilloscopes and options Operators Manual (May 88) the manual number70-6860-00
2467B Library_text searchable 070-6861-00.pdf
2467B Ops text searchable.pdf

As a group, do we have a source to which we refer? In my list you may notice the manual number such as: 070-6863-00 BUT!!! 070-6863-00 and 070-6863-01 are called Service Manual when you open either. You my note I added at the end of a line: searchable or no search. That is, some I can search for "waveforms" and others I cannot.

Thank you, larry

Re: Paying it forward with David's Part's Exchange

David Berlind
 

Here's the crazy thing. Most of these parts just came with the things I
really wanted: 5 parts bins. I needed more bins to keep the parts that I
actually use. The guy sold them to me for $5 each and then he gave me 3 or
4 boxes just full of other stuff to go with it. For example, I think I have
about 200 brand new, individually wrapped banana jack extenders. But the
drawers in the bins were full. As I go through the inventory of stuff, some
of these parts sell for $3 or $4 each and I have anywhere between 10 and 40
of each. I'm guessing it's several thousand dollars in inventory that I got
for 25 bucks.

On Sun, Dec 15, 2019 at 9:40 PM nonIonizing EMF <nonionizingemf@...>
wrote:

I recently ordered some components with the same thought and intent,
needed about 8 and had to order 50, though I noted on Hackaday. I'll
email you to update the list with the components I have once I get a more
accurate inventory. I have a bunch of 0603 SMD components also. Thanks
David.



Re: TM5xx/TMxxx Pass Transistors. SUBJECT CHANGE, WAS: DC-508 repair advice

Dave Seiter
 

Thanks, Dennis!
I hadn't seen this list before, and I'm sure it will come in handy.
-Dave

On Sunday, December 15, 2019, 12:55:17 PM PST, Dennis Tillman W7PF <@Dennis_Tillman_W7pF> wrote:

Hi Michael and all TekScopes members,

As my late friend, Jerry Scheltgen (AKA Kilowatt on eBay), and I once documented, knowing which pass transistors are used in which TM500 / TM5000 mainframe, is not easy to figure out because Tek changed them often and some mainframes use different ones for no apparent reason. To make matters worse on some occasions Tek changed to a different transistor with ENTIRELY DIFFERENT lead order so they require contortions to reorient the leads to make them reach the holes the old leads went into.

To solve this mess in 8/2014, Jerry and I documented which pass transistors were used where and when you had to be careful because the lead orientation mattered.

I uploaded the list we created just now. It can be found at
https://groups.io/g/TekScopes/files/TM5xxx%20Pass%20Transistor%20List.pdf

If you search our archives of messages regarding any topic with "pass transistors" you will find several recommendations our members made for "better" or "more powerful" or "more sensitive" or "less expensive" or "more available" substitutes for what Tek used. The only consideration I would caution that you observe it is desirable (to prevent oscillation) that the pass transistor have a low cutoff frequency (Ft). Less than 1 MHz would be ideal.

Dennis Tillman W7PF
   
-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Mlynch001
Sent: Sunday, December 15, 2019 11:51 AM
Subject: Re: [TekScopes] DC-508 repair advice

The hard part is finding replacement transistors for the pass transistors.  I blew one up by plugging one of my plugins onto my extension cable upside down.  The plugin extension did not have an indexing pin, so it would fit either way. 
--
Michael Lynch
Dardanelle, AR




--
Dennis Tillman W7PF
TekScopes Moderator

Re: telonics sweep generator

Dave Seiter
 

I Have a Telonics SM2000 that I've never really played with.  I might have it's manual, I don't remember.
-Dave

On Sunday, December 15, 2019, 07:24:03 PM PST, battyhugh <@Hugh> wrote:

Hi  I have a Telonics 2003 sweep generator - has anyone still got one? - or a manual. I have had it for years mouldering away in the store room. As it is dual voltage - I can run it here (but the original 3 pin plug seems unobtainable) - it's a beautiful piece of late 1960's US technology  - and I'd like to get it going.
(that's what spectrum analysers are for!) - thanks and Cheers
Hugh

Re: Tek 2465 Problem

Chuck Harris
 

Is your scope working properly, or is it having some sort
of problem?

There are frequently problems with the CA3046 transistor
arrays, which will cause glitching in the CH1 and 2 traces
when they fail in the little addition around CH5 of the
channel hybrid.

-Chuck Harris

Panos wrote:

Hello to all.
Taking some measurements on my TEK 2465 using another oscilloscope, I see something strange.

I read for CHN5B signal -1,2 Volt versus -3,6 Volt. This only with BW LIMIT off.
Also for CHN 5A I read signal 600mV p-p versus -6 Volt as look at waveforms on service manual.

Am I doing something wrong, or I have problem somewhere in my TEK scope?

Waveforms 28 and 46 in pages 238 and 239 in service manual. These appears in diagram No 5 in page 244.



Re: telonics sweep generator

Glenn Little
 

On 12/15/2019 10:23 PM, battyhugh wrote:
Hi I have a Telonics 2003 sweep generator - has anyone still got one? - or a manual. I have had it for years mouldering away in the store room. As it is dual voltage - I can run it here (but the original 3 pin plug seems unobtainable) - it's a beautiful piece of late 1960's US technology - and I'd like to get it going.
(that's what spectrum analysers are for!) - thanks and Cheers
Hugh


--
-----------------------------------------------------------------------
Glenn Little ARRL Technical Specialist QCWA LM 28417
Amateur Callsign: WB4UIV wb4uiv@... AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) USSVI LM NRA LM SBE ARRL TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"

telonics sweep generator

battyhugh
 

Hi I have a Telonics 2003 sweep generator - has anyone still got one? - or a manual. I have had it for years mouldering away in the store room. As it is dual voltage - I can run it here (but the original 3 pin plug seems unobtainable) - it's a beautiful piece of late 1960's US technology - and I'd like to get it going.
(that's what spectrum analysers are for!) - thanks and Cheers
Hugh

Re: TM5xx/TMxxx Pass Transistors. SUBJECT CHANGE, WAS: DC-508 repair advice

 

Hi Michael,
There a lots of possible replacements provided the voltage, current, and power ratings are equivalent. The other thing to watch for is be sure the replacement pass transistor leads are in the same order as the originals. Tek changed the parts they used over the years and you must make sure your replacements have the same order for the E, B, and C pins. Beyond these 4 things the package outline is the only other detail that you need to match.

The rightmost slot of the TM504, TM506, and TM5006 are high power compartments so they probably have beefier pass transistors.

Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Mlynch001
Sent: Sunday, December 15, 2019 1:49 PM
Subject: Re: [TekScopes] TM5xx/TMxxx Pass Transistors. SUBJECT CHANGE, WAS: DC-508 repair advice

Dennis,

I was able to find the original specs for my particular unit and then found some replacements that I thought might work. It has 5 bays with the same NPN and PNP parts and the high power compartment used something different. I found some replacements and then used the curve tracer to match the old parts to the new parts as close as possible. I’m going to look at what you have written, to see how close I got by dead reckoning and using my Curve Tracer. I appreciate your guidance, I always learn something from the members of this group.

--
Michael Lynch
Dardanelle, AR




--
Dennis Tillman W7PF
TekScopes Moderator

Re: Paying it forward with David's Part's Exchange

nonIonizing EMF
 

I recently ordered some components with the same thought and intent, needed about 8 and had to order 50, though I noted on Hackaday. I'll email you to update the list with the components I have once I get a more accurate inventory. I have a bunch of 0603 SMD components also. Thanks David.

Re: Paying it forward with David's Part's Exchange

David Berlind
 

Just noticing that the web version masked my email address. So, just in case you didn't get it... it is my first name at my last name (berlind) dot "org".

Re: Paying it forward with David's Part's Exchange

David Berlind
 

Thanks Dennis...

Anyone who is interested in something that I've listed should contact me
off-group via email at david@....

The process will basically be:

1. Double check that I have the part (please only request parts that I've
listed)
2. Give you an address to send your SAS-package to.
3. I'll return the package to you with the part

Thanks.

David

On Sun, Dec 15, 2019 at 2:37 PM Dennis Tillman W7PF <@Dennis_Tillman_W7pF>
wrote:

David,

Please provide YOUR STREET ADDRESS for people to send to you for your list
or include YOUR EMAIL ADDRESS.

Interested members PLEASE contact David Berlind directly if you are
interested in his generous offer.
All inquiries should be handled OFF-LIST to keep unnecessary personal
correspondence off of TekScopes.

Dennis Tillman W7PF


-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of David
Berlind
Sent: Saturday, December 14, 2019 9:18 AM
Subject: [TekScopes] Paying it forward with David's Part's Exchange

Hi Tekkies...

I have launched a Google Spreadsheet that I am very slowly updating with
the inventory of all my parts. In an effort to pay it forward to you and
others that have been so generous in helping me to get my fingernails
dirty, I'm making 99% of the parts available to anyone for free.
Personally, it drives me nuts I need one part and I have to pay more to buy
it in bulk, or the shipping costs more than the part itself. I will never
use most of these parts and so I'd rather give them away (not in bulk). All
I ask is that you send me a self-addressed stamped envelope (or other
packaging) and I will put the part in that packaging and return it to you.
It's going to take me months to get this spreadsheet fully up to date.
Maybe years. I don't know. But each week, I'm chipping away at the iceberg,
adding new parts. So, let me know if you see something you need or like.
I'm calling this David's Part Exchange. Let me know if you have any
questions.
https://docs.google.com/spreadsheets/d/1Q4M7dnS--TXb5PW1VqEBmM2Sxonknz0vVFVk_rfho_o/edit#gid=437389817




--
Dennis Tillman W7PF
TekScopes Moderator



Re: Paying it forward with David's Part's Exchange

David Berlind
 

Thanks Michael. If you want me to add tabs to my spreadsheet that list your
inventory, let me know.

On Sat, Dec 14, 2019 at 1:41 PM Mlynch001 <@mlynch001> wrote:

David,

Very Generous of you. You have inspired me to consider doing something
similar for those on this forum.

--
Michael Lynch
Dardanelle, AR



Re: DC-508 repair advice

Mlynch001
 

This sounds interesting! I need to look into this further.

--
Michael Lynch
Dardanelle, AR