Date   

Re: Scopes in nuclear testing - was Re: [TekScopes] Tek 7103 found at auction in NM

Clark Foley
 

I found a few photographs, before and after, of a few of the racks of R7103s and R7903s with the custom cameras attached. In all, some 32 million dollars worth of test, monitoring, recording and diagnostic equipment was lost due to the containment door failure.
The photographs are posted in the album named Mighty Oak.


Re: Tek 7103 found at auction in NM

Dave Wise
 

I have never implemented any of the Kick Starts, but the last one should be the best. Remember, these were just design exercises to scratch an itch.
I put the TL431 in my first 141T. If the second one turns out to have a regulator tube, I’ll try KS9.

Dave Wise

From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of nonIonizing EMF via groups.io
Sent: Tuesday, August 24, 2021 2:20 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Tek 7103 found at auction in NM

Dave, or anyone else with experience with the TL431 VR tube replacement designs, which Kick Start or other version is you perfected design?

I haven't studied tube designs much and have no hands on experience. However, seems like great info to know for the 141 and possible others I might find in the future.

Reads like this link has the design iterations: https://groups.io/g/HP-Agilent-Keysight-equipment/photo/68333/2?p=Name,,,20,1,0,0<https://groups.io/g/HP-Agilent-Keysight-equipment/photo/68333/2?p=Name,,,20,1,0,0>

Figured I'd ask for future reference.

James


On Tue, Aug 24, 2021 at 07:46 AM, Dave Wise wrote:


I perfected Ed Breya’s suggestion of replacing it with a TL431 plus
excess-voltage-absorbing zener.


Re: Tek 7103 found at auction in NM

Jim Ford
 

LOL at the prospects of treating scopes like that, Roy!             Jim Ford Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------From: Roy Thistle <roy.thistle@mail.utoronto.ca> Date: 8/24/21 2:32 PM (GMT-08:00) To: TekScopes@groups.io Subject: Re: [TekScopes] Tek 7103 found at auction in NM On Mon, Aug 23, 2021 at 12:47 PM, stevenhorii wrote:>> I'm a radiologist>So... I'm guessing unless you're doing radio-oncology, or nuclear medicine, most of the ionising radiation you deal with is x rays.But, I want to ask... if you get the chance to commentAFAIK, much of the danger from the effective dose, or absorbed dose... caused by the radionuclide decay you described... would be if those radionuclides come to be entered into the body.For example, polonium-210 is a rare but energetic alpha emitter, but is considered very dangerous only when ingested. You didn't mention neutron emitters. But Americium 241 is an alpha neutron emitter that is/was commonly used in smoke detector/alarms.On the other hand...Technetium-99m is a gamma emitter; but, it is routinely used for nuclear medicine imaging, as a solute in solution, given intravenously. Doctors aren't supposed to kill their patients.So I guess my point is...Unless you lick your fingers, lick your oscilloscopes clean, make tea from oscilloscope knobs, or grind up scopes and smoke them... how much danger is there from potentially radioactive oscilloscopes?... potentially contaminated decades ago. -- Roy Thistle


Re: Tek 7103 found at auction in NM

Roy Thistle
 

On Mon, Aug 23, 2021 at 12:47 PM, stevenhorii wrote:


I'm a radiologist
So... I'm guessing unless you're doing radio-oncology, or nuclear medicine, most of the ionising radiation you deal with is x rays.
But, I want to ask... if you get the chance to comment
AFAIK, much of the danger from the effective dose, or absorbed dose... caused by the radionuclide decay you described... would be if those radionuclides come to be entered into the body.
For example, polonium-210 is a rare but energetic alpha emitter, but is considered very dangerous only when ingested.
You didn't mention neutron emitters. But Americium 241 is an alpha neutron emitter that is/was commonly used in smoke detector/alarms.
On the other hand...Technetium-99m is a gamma emitter; but, it is routinely used for nuclear medicine imaging, as a solute in solution, given intravenously. Doctors aren't supposed to kill their patients.
So I guess my point is...
Unless you lick your fingers, lick your oscilloscopes clean, make tea from oscilloscope knobs, or grind up scopes and smoke them... how much danger is there from potentially radioactive oscilloscopes?... potentially contaminated decades ago.



--
Roy Thistle


Re: Tek 7103 found at auction in NM

nonIonizing EMF
 

Dave, or anyone else with experience with the TL431 VR tube replacement designs, which Kick Start or other version is you perfected design?

I haven't studied tube designs much and have no hands on experience. However, seems like great info to know for the 141 and possible others I might find in the future.

Reads like this link has the design iterations: https://groups.io/g/HP-Agilent-Keysight-equipment/photo/68333/2?p=Name,,,20,1,0,0

Figured I'd ask for future reference.

James

On Tue, Aug 24, 2021 at 07:46 AM, Dave Wise wrote:


I perfected Ed Breya’s suggestion of replacing it with a TL431 plus
excess-voltage-absorbing zener.


Re: Tek 7103 found at auction in NM

ChrisBeee
 

Jeff,

I got one of these plug-ins (very rare over here in Germany) a while ago. It's an Ino-tech 5200 Multichannel Scaler / Integrator and it is intended to live in a 5000 series scope. One modification in particular, necessary to make it work, is 'ambitious' to say the least! There are a couple of unused pins in the upper area of the plug-in edge connector and the plug-in asks for 220VAC because it has its own transformer. Obviously, the 5000 series power supplies did not have enough oomph to feed this plug-in. Bet what you need to do? Route mains AC from the primary AC windings to these contacts (I have created the album 'Ino-tech 5200 plug-in for 5000 series scopes', see the twisted yellow wires going to the right plug-in edge connector in one of the pictures). Don't want to know if you insert whatever 5000-series plug-in that has these contacts used in a different way...Very scary! I have fixed the plug-in to the frame and put a sticker on it in case someone else screws around with this apparatus once I'm six feet under.
Found the necessary wiring to feed the horizontal section, but still could not figure out how to connect the vertical amp. Either there was additional circuitry necessary or a modification in the scope directly to bring it to life. Dunno...

BTW: if anybody is in the possession of an Ino-tech 5200 schematic: I would be very grateful if I could obtain an (electronic) copy!

Chris

On Mon, Aug 23, 2021 at 10:35 PM, Jeff Kruth wrote:


Hi Steve!Yep, third party folks bought 5000 series scopes and made
multichannel analyzers (MCA's) out of them for energy spectrum. I have a
couple in the back room. They have died and I dont want to troubleshoot early
'70's uP units.... Jeff Kruth In a message dated 8/23/2021 3:47:55 PM
Eastern Standard Time, sonodocsch@gmail.com writes:
I wonder if Tek or a third-party manufacturer ever made a plug-in
for one of the Tek scopes that would turn it into a gamma spectrometer. I
know some nuclear medicine systems had Tek displays with custom electronics
that did this.


Re: Tek 7103 found at auction in NM

Roy Thistle
 

Hi George:
I read your message.
Well... if your mad at me... why?
The scopes were "hot" and you were at Brookhaven: and likely got NRC training.
Given that... a natural question is... what radionuclide(s) containing particulates were the scopes contaminated with? (Or, was it neutron activation?)
If it isn't known what the exposure was, and the dose... saying the scopes were "hot" ... IMO... isn't saying anything meaningful.
There is a lot of nonsense, and fear generated, around the mentioning of radiation.
People ought to ask about it.
Perhaps... since your job was working with radiation... if you get a chance... you'd like to explain.

--
Roy Thistle


Re: CRT for a 546

 

Dave,

Oh dear, well that’s unfortunate. If I’m lucky the lack of traces will be some other issue (and that’s still quite likely, since I haven’t really started to investigate the CRT circuitry yet). There’s also a lot more work to do on the scope, including what will likely be a complete jokers disassembly (several chassis members are deformed) so I’ve got time to wait for something to turn up, if it turns out to be needed.

- Jeff Dutky


Re: tunnel diodes retrace lines in curve tracer

Miguel Work
 

Did you find your notes?


Re: Corona advice - no not that one!

Michael W. Lynch
 

On Tue, Aug 24, 2021 at 11:21 AM, n4buq wrote:


It looks like Dow Corning RTV 732 uses acetoxy curing. Wouldn't that be
ill-advised in this application?

Thanks,
Barry - N4BUQ
Barry,

Good point. This was recommended by a HV transformer manufacturer I would need to investigate the recommendation further and report back. Thanks for bringing this up.

--
Michael Lynch
Dardanelle, AR


Re: Corona advice - no not that one!

n4buq
 

It looks like Dow Corning RTV 732 uses acetoxy curing. Wouldn't that be ill-advised in this application?

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Michael W. Lynch via groups.io" <mlynch003=yahoo.com@groups.io>
To: TekScopes@groups.io
Sent: Tuesday, August 24, 2021 11:10:19 AM
Subject: Re: [TekScopes] Corona advice - no not that one!

Regarding the use of "Black RTV", Certain RTV's are excellent insulators.
Keep in mind that TEK used silicone potted HV transformers in the later
Type 576.

Here is one recommended product: Dow Corning RTV 732 BLACK This product has
excellent Electrical properties. Full Datasheet is available online here:
https://www.farnell.com/datasheets/91600.pdf.

Here are some relevant electrical details.

"Electrical properties, cured 7 days in air at 25°C (77°F) and 50% relative
humidity.

Dielectric strength: 21.6kV/mm per ASTM D149
Dielectric constant at 100Hz/100kHz: 2.80112 per ASTM D150
Dissipation factor at 100Hz/100kHz: 0.0015 per ASTM D150 "

There are likely more materials available that will do the job.

--
Michael Lynch
Dardanelle, AR






Re: Scopes in nuclear testing - was Re: [TekScopes] Tek 7103 found at auction in NM

Greg Muir
 

I picked up several 500 series scopes several decades ago directly from the then Rocky Flats nuclear trigger processing plant in Colorado. It turned out that one of them was quite smoked up from apparently being in a fire. I had remembered that there was a news story a few years earlier where the evacuation ductwork in one of the Plutonium processing buildings had caught fire and everything in the structure was contaminated. I was preparing for a move so packed the scopes in crates and to this time I still haven’t brought them out to see the light of day.

Always wondering if……

Greg


Re: Corona advice - no not that one!

Michael W. Lynch
 

Regarding the use of "Black RTV", Certain RTV's are excellent insulators. Keep in mind that TEK used silicone potted HV transformers in the later Type 576.

Here is one recommended product: Dow Corning RTV 732 BLACK This product has excellent Electrical properties. Full Datasheet is available online here: https://www.farnell.com/datasheets/91600.pdf.

Here are some relevant electrical details.

"Electrical properties, cured 7 days in air at 25°C (77°F) and 50% relative humidity.

Dielectric strength: 21.6kV/mm per ASTM D149
Dielectric constant at 100Hz/100kHz: 2.80112 per ASTM D150
Dissipation factor at 100Hz/100kHz: 0.0015 per ASTM D150 "

There are likely more materials available that will do the job.

--
Michael Lynch
Dardanelle, AR


Re: Corona advice - no not that one!

Michael W. Lynch
 

On Tue, Aug 24, 2021 at 10:27 AM, Jeff Dutky wrote:


Michael,

(taking a sip of coffee with visibly shaking hands) that advice would have
been slightly more useful last fall, when I was actively poking around the HV
section of a 475A.

-- Jeff Dutky
Jeff,

Thankfully, those voltages are typically well insulated and hidden from view for the most part. But the CRT can get dirty and leak anode voltage where it should not go. The CRT can store considerable voltage, as you know. But the bottom line is, that HV multiplier can deliver a nasty shock under the right circumstances. It pays to be very careful with these HV sources. .

--
Michael Lynch
Dardanelle, AR


Re: Corona advice - no not that one!

benx618(g)
 

How nice it is to read corona discussion devoid of the word virus.

Ben


Re: CRT for a 546

Dave Wise
 

581A/585A is out due to their using distributed deflection. 545/545A are designed for 500V less on the cathode, 500V more on the anode. Even if the deflection factors work, you may have geometry trouble. If you have nothing to lose, I suppose you could replace the transformer with a 545 part and re-trim the regulator and geometry so you’re using 545 voltages throughout, and see how it goes. But I would bet real money you’ll end up with transients that you can’t trim out, simply because the 546 output amp was designed to terminate at 546 deflection plates.

Dave Wise

From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Jeff Dutky via groups.io
Sent: Tuesday, August 24, 2021 8:03 AM
To: TekScopes@groups.io
Subject: [TekScopes] CRT for a 546

I'm in the early stages of restoring a 546 and I'm worried that the CRT is dead (even after fixing a couple of issues I've still got nothing on the CRT, not even a faint glow). While it's too early to really be worrying about this (I haven't even checked the HV section) I would like to know what my options are in case I need to replace the CRT. I don't see any 546 CRTs (PN 154-429 or T5470) for sale on the auction site, but I see CRTs for the 545, 545A, 581A, and 585A. Can I adapt one of these tubes to the 546 if necessary?

-- Jeff Dutky


Re: Corona advice - no not that one!

 

Michael,

(taking a sip of coffee with visibly shaking hands) that advice would have been slightly more useful last fall, when I was actively poking around the HV section of a 475A.

-- Jeff Dutky


Re: Corona advice - no not that one!

Michael W. Lynch
 

On Tue, Aug 24, 2021 at 09:39 AM, Jeff Dutky wrote:


"ONLY like 10kV" seems like hyperbolic understatement to me (but the scope's
I've worked most on, the 475 and 2200-series, use unusually low cathode
potentials)

-- Jeff Dutky
Jeff,

Keep in mind that the HV Multiplier of the 465/475 supplies about 14kV PDA to the Anode terminal of the CRT..

--
Michael Lynch
Dardanelle, AR


CRT for a 546

 

I'm in the early stages of restoring a 546 and I'm worried that the CRT is dead (even after fixing a couple of issues I've still got nothing on the CRT, not even a faint glow). While it's too early to really be worrying about this (I haven't even checked the HV section) I would like to know what my options are in case I need to replace the CRT. I don't see any 546 CRTs (PN 154-429 or T5470) for sale on the auction site, but I see CRTs for the 545, 545A, 581A, and 585A. Can I adapt one of these tubes to the 546 if necessary?

-- Jeff Dutky


Re: Corona advice - no not that one!

 

On Tue, Aug 24, 2021 at 04:41 PM, Dave Wise wrote:


black on the tripler ceramic strip, that’s corona dope
Probably GC #47-2 by GC Electronics, Tek P/N 006-0541-00

/Håkan

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