Date   
Re: Barrie Gilbert has passed away

guy232
 

I remember enjoying your story a couple weeks ago about you meeting him. Oddly enough later that day after reading your story I was out shopping with my girlfriend who just so happened to purchase the book "Peter Pan" of whom you mentioned Barrie was named after the author, was quite the coincidence.

RIP, sounded like a talented man.

Re: voltage limit of CA plugin

Chuck Harris
 

If the little AC/DC/GND switch can handle the voltage.

Tektronix was silent on the issue, which usually means
you have to hope you are lucky.

-Chuck Harris

John Williams wrote:

Jamie the input capacitor is specd at 600 vdc. That means that the input dc plus peak ac should not exceed 600.



Re: voltage limit of CA plugin

Jamie Ostrowski
 

Thanks John. Is there a chance that even though that capacitor was spec'd
at 600 volts there may be a possibility that other components in the
circuit aren't - that they tossed in the 600 VDC rated capacitor because
they already had a large supply at that voltage rating at the factory that
they used in other designs when in fact the rest of the circuitry could not
actually handle the full spec of the cap? That's why I was hoping the
manual would say but it doesn't. I'm probably being overly cautious but I'm
a novice who has never played with these voltage levels before on this
equipment and I'm probably overthinking it.

You've been working with these scopes so long though if you think it's fine
then I'll give it a shot.

On Sat, Feb 1, 2020 at 3:49 PM John Williams <books4you@...> wrote:

Jamie the input capacitor is specd at 600 vdc. That means that the input
dc plus peak ac should not exceed 600.



Re: 5111 Storage Scope Loss of -30VDC

Tim Phillips
 

From Tim P (UK)

I have a manual, thanks - in fact, after perusing the schematic, I realised
that my +38 V on the +30V test point is the UNREG voltage.
So, maybe the erstwhile +30V is not being regulated at all. I will check
around the +30V circuitry. Are the Darlington pass transistors (MJE800)
reliable with age ?

Tim

On Sat, 1 Feb 2020 at 21:06, p mc <pmc@...> wrote:

Tim,

TekWiki has a complete 5441 manual. http://w140.com/tekwiki/wiki/5441
It doesn't have "voltage and waveform" data but has the schematic, board
layout, adjustment & Theory of Operation info.

Do you have that?

pmc

On Fri, Jan 31, 2020 at 10:14 AM, Tim Phillips wrote:


from Tim P (UK)
re the 5111 - what was the problem with the -30V ?
I have a 5441 with a low -15V (11V) and a high +30V (+38V)
The LVPS in the 5000-series seem to be very similar. I would be
interested
in your investigations and cure
regards
Tim


On Thu, 30 Jan 2020 at 18:13, Mlynch001 <@mlynch001> wrote:

I believe that the "stuff" is a sealer of some sort that TEK used on
many
of their flush socket units. I see this on many of the newer TM5XX
plug
ins as well as many scopes that use those soldered into the board pin
sockets.


--
Michael Lynch
Dardanelle, AR





Re: voltage limit of CA plugin

John Williams
 

Jamie the input capacitor is specd at 600 vdc. That means that the input dc plus peak ac should not exceed 600.

Re: 5111 Storage Scope Loss of -30VDC

p mc
 

Tim,

TekWiki has a complete 5441 manual. http://w140.com/tekwiki/wiki/5441
It doesn't have "voltage and waveform" data but has the schematic, board layout, adjustment & Theory of Operation info.

Do you have that?

pmc

On Fri, Jan 31, 2020 at 10:14 AM, Tim Phillips wrote:


from Tim P (UK)
re the 5111 - what was the problem with the -30V ?
I have a 5441 with a low -15V (11V) and a high +30V (+38V)
The LVPS in the 5000-series seem to be very similar. I would be interested
in your investigations and cure
regards
Tim


On Thu, 30 Jan 2020 at 18:13, Mlynch001 <@mlynch001> wrote:

I believe that the "stuff" is a sealer of some sort that TEK used on many
of their flush socket units. I see this on many of the newer TM5XX plug
ins as well as many scopes that use those soldered into the board pin
sockets.


--
Michael Lynch
Dardanelle, AR



Re: 5111 Storage Scope Loss of -30VDC

p mc
 

Of course I've nev<cough>r put a cap in backwards...

I don't have a 51xx scope, but I looked at a bunch of 51xx manuals & schematics in the course of figuring out 5D10/mainframe interaction (https://groups.io/g/TekScopes/message/163941).

The 5110.pdf manual at BAMA includes change notes up to 1987 so it likely covers your scope. Do you have that? It includes lots of "voltage and waveform conditions" info that should help since you also have a working scope.
http://bama.edebris.com/manuals/tek/5110/

I'm curious: do your 5110 & 5111 have a perpendicular daughter card stuck out the back of the interface board (where the plugins plug in)?

pmc

Re: voltage limit of CA plugin

Albert Otten
 

The advantage of 100X probes P6007 and P6009 is that the divider is (mostly) inside the probe. Then the input capacitor sees not a high voltage.
Albert

Re: voltage limit of CA plugin

Jamie Ostrowski
 

Thanks Nenad. This gives me some things to think about. I also do have a
1A1 plugin so I may go with that. It is rated for 600V but to your point
due to the age I'm really pushing things to the max. I was just curious if
anyone knew about the voltage range of the CA since it is so common.

On Sat, Feb 1, 2020 at 4:56 AM Nenad Filipovic <ilmuerte@...> wrote:

Damn, I typed my answer before I was fully awake. HV probes are certainly
handy, but their attenuation might be a problem if you want to measure
noise in the millivolts range on top of a few hundred volts rail (case
common with tube voltage regulators). For that you might put the CA into DC
input mode and use an external high voltage capacitor (e.g. 100nF 1kV) to
filter out the DC component. But you'd also need a surge suppressor circuit
to handle charging of that capacitor once you touch the rail to be
measured. A 1K-ish wire-wound resistor in series with the external
capacitor together with two zeners (in series, cathode-cathode or
anode-anode connected) in parallel with the CA input might do the trick.
You could size the zeners according to the Volts/div range you'd be using
on the CA.

Best Regards,
Nenad



Re: 2465B - Weak Readout Intensity

Bruce Atwood
 

( I sent this some time ago but I think I only sent it to myself, I'll try again)

When I was servicing TV's (mid 60's!) we carried, in our tube caddy, tiny auto-transformers that would, for most BW tubes plug inline with the socket and boost the heater voltage by a volt or so. For Color tubes you would have to do a couple of cuts and splices. It was always the red gun. We also had a " Cathode Rejuvenator " Which would basically draw and arc between G1 and the cathode, the theory being that you could get a new oxide surface on the cathode. When it worked it was great, when it went bad the CRT was dead. There are several rejuvinators on ebay. If you are resigned to buying a new tube it might be worth it. The other trick, which is truly bold, is to whack the neck against your hand. Here the theory is that you might be able to move the cathode to the side, exposing and unused section of the oxide. Definitely wear leather gloves and a full face shield.


good luck

Re: 2465B - Weak Readout Intensity

flanneltuba@...
 

I finally found the time to check the DAC sample-and-hold circuits for the Intensity signals, and they tested perfectly fine. Both the readout and display levels (ROIR and DIR) at the output of the op amps (U2630A and B) as well as the downstream signals where they arrive at pins 23 and 22 respectively on the Display Sequencer (U650), all show as fully responsive and their voltage levels follow the front panel intensity controls all the way through their rotation range. This also exonerates the A5 DAC circuit itself, which I previously spent a fair amount of time cleaning, validating components and recalibrating.

I've also swapped out both the Display Sequencer and the Z-Axis Amplifier ICs (U650 and u950) with known good chips, to no avail.

So I believe Chuck was right on this one: It's down to the CRT. I have a CRT on order which should be here in the next week. I was not able to ascertain from the seller if it was a bona-fide 2465A/B tube or the plain 2465 tube. The eBay seller (part2go from Israel) has been utterly unresponsive to my repeated inquiries. I should have listen to Chuck's advice to order from Dinos in Greece! I was being a cheapskate and went with a $53 tube. Ah well, if I have to order another one from Greece for $150, well, that's what I call "tuition" in the school of life. At lease now, with the $50 CRT I'll be able to prove that the CRT is in fact the faulty player. I don't like just tossing money into a hole like this, but I can always resell the cheap tube, or hold onto it and gift it to someone else down the line who needs one.

TDS3000B USB floppy emulator

Tom B
 

Hello All,

Can someone tell me which USB floppy emulator will fit and function in the TDS3000B scopes?

I found some on ebay that say they are for the TDS3000 but they are a bit pricey.

Tom Bryan
N3AJA

Re: 5111 Storage Scope Loss of -30VDC

Bob Wilson
 

OK, I must confess I had the replacement cap in backwards. A new cap with the correct polarity fixed the -30V problem.
I still would like some tips on how to troubleshoot the 5110 scope. The horizontal circuit appears to not be working. I think I have read that the transformer is a a common problem.
Bob

Re: Guernsey Island 2445

Colin Herbert
 

I have (painstakingly) gone through my non-Beaverton Tek gear and the serial-numbers and here is the result:

7623A Guernsey 100195
7A13 Guernsey 104748
7A13 Guernsey 101247
7A16A Guernsey 100171
7A18 Guernsey 100717
7A18 Guernsey 106430
7A18 Guernsey 102640
7A18(Opt.6) Guernsey 102481
7A18A Guernsey 118496
7A26 Guernsey 102925
7B53A Guernsey 110259
7B53A Guernsey 104565
7B50 Guernsey 100235
7B51 Guernsey 100078
7B70 Guernsey 102168

TM503 UK 200778

453 Guernsey 102671
466(Opt.7) Heerenveen 704422
468 Heerenveen 710840
475A Heerenveen 706343
475A(w/DM44) Heerenveen 710664

Note that none of these has any initial letters. It is probably worth adding that not all of these are fully functional and am not trying to show how well-equipped I am. Since I typed this out using the "TAB" key, it might be that Groups.io won't tabulate it correctly. E &OE.

Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Charlie.c
Sent: 31 January 2020 01:22
To: TekScopes@groups.io
Subject: Re: [TekScopes] Guernsey Island 2445

I do not but do remember this being discussed several times. My experience was from 1980-2011. It seemed that most of the instruments followed the letter manufacturing convention you show above in 1988.
As far as correlation between units manufactured in various locations I am not aware of any system.

Re: voltage limit of CA plugin

Nenad Filipovic
 

Damn, I typed my answer before I was fully awake. HV probes are certainly
handy, but their attenuation might be a problem if you want to measure
noise in the millivolts range on top of a few hundred volts rail (case
common with tube voltage regulators). For that you might put the CA into DC
input mode and use an external high voltage capacitor (e.g. 100nF 1kV) to
filter out the DC component. But you'd also need a surge suppressor circuit
to handle charging of that capacitor once you touch the rail to be
measured. A 1K-ish wire-wound resistor in series with the external
capacitor together with two zeners (in series, cathode-cathode or
anode-anode connected) in parallel with the CA input might do the trick.
You could size the zeners according to the Volts/div range you'd be using
on the CA.

Best Regards,
Nenad

Re: voltage limit of CA plugin

Nenad Filipovic
 

No idea as well, but most likely it will be your probe that will determine
the max voltage to be worked on. That is if you're using the "usual" x10 or
higher attenuation probes like you should.

CA plugin uses a 600V capacitor for the AC input mode (which is what you'd
be using to measure ripple). Given the age of any CA today, I'd derate that
somewhat.

Tek P6007 or P6009 probes (x100, 1.5kV) would be suitable for your
application and most work on tube circuits. For low freq work like mains
ripple you might even improvise one using multiple resistors in series.

Best Regards,
Nenad

On Sat, Feb 1, 2020 at 6:54 AM Jamie Ostrowski <jamie.ostrowski@...>
wrote:



Does anyone know what the upper voltage limit is on the CA plugins? I
couldn't find the spec in the manual, and I'm interested in measuring
ripple in a 550 VDC power supply so I want to be sure I'm not overloading
anything.


Thanks,

- Jamie

voltage limit of CA plugin

Jamie Ostrowski
 

Does anyone know what the upper voltage limit is on the CA plugins? I couldn't find the spec in the manual, and I'm interested in measuring ripple in a 550 VDC power supply so I want to be sure I'm not overloading anything.


Thanks,

- Jamie

Re: Barrie Gilbert's 2007 Biographical Story

Raymond Cote
 

Great! Thanks. Ill read it.

On Jan 31, 2020, at 18:50, Dennis Tillman W7PF <@Dennis_Tillman_W7PF> wrote:

I placed a fascinating article about his life in our archives. It is at https://groups.io/g/TekScopes/files/Barrie%20Gilbert%20Biography%20IEEE%20SSCN%20News%20Fall%202007.pdf

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Mlynch001
Sent: Friday, January 31, 2020 6:46 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Barrie Gilbert has passed away

Dennis,

I had just recently finished reading Barrie's Biography in the IEEE SSCS NEWS from 2007, a supremely fascinating story. This would be a good starting place for anyone wanting to learn more about Mr. Gilbert. I am not sure that the term "giant" comes close to what this man has meant to mankind as a whole. His contributions will live on, probably for centuries? This is a sad day for us all.

Michael Lynch
Dardanelle, AR




--
Dennis Tillman W7PF
TekScopes Moderator


Barrie Gilbert's 2007 Biographical Story

 

I placed a fascinating article about his life in our archives. It is at https://groups.io/g/TekScopes/files/Barrie%20Gilbert%20Biography%20IEEE%20SSCN%20News%20Fall%202007.pdf

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Mlynch001
Sent: Friday, January 31, 2020 6:46 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Barrie Gilbert has passed away

Dennis,

I had just recently finished reading Barrie's Biography in the IEEE SSCS NEWS from 2007, a supremely fascinating story. This would be a good starting place for anyone wanting to learn more about Mr. Gilbert. I am not sure that the term "giant" comes close to what this man has meant to mankind as a whole. His contributions will live on, probably for centuries? This is a sad day for us all.

Michael Lynch
Dardanelle, AR




--
Dennis Tillman W7PF
TekScopes Moderator

Re: Barrie Gilbert has passed away

nonIonizing EMF
 

On Fri, Jan 31, 2020 at 06:01 PM, Dennis Tillman W7PF wrote:


I lost a friend! We lost a giant analog IC designer! Barrie passed away
after a fall yesterday.
Wow! I literally watched w2aew's video on the Gilbert Cell maybe three days ago: https://www.youtube.com/watch?v=7nmmb0pqTU0

I've been studying the various mixer, divider and multiplier circuit designs... from the AD datasheets circuit references on the AD831 as well as Mini-Circuits ADE-1 and ADE-24MH. Those datasheets are what got me inquiring more.

Not to sound paranoid... though I'd be rationally paranoid when the U.S. is at War and our domestic policy let's anyone in the World come in with remote sensing and remote transmission systems. I'm hoping there isn't an alarming trend that is being written off as "baby boomers" causation.

Seems there isn't as much an interest in our National Intelligence Brain Trust as much as the National Security Internal Affairs National Security farce compounding and concealing remote sensing and remote transmission poaching that the latest CBS News 60 Minutes report barely detailed and others have been advocating threat awareness of the imminent threat situation then being written off invalidly.
https://www.cbsnews.com/news/brain-trauma-suffered-by-u-s-diplomats-abroad-could-be-work-of-hostile-foreign-government-60-minutes-2019-09-01/