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Tek 2430A hybrid compatiblity.

Max Frister
 

I'm back working on the 2430a. I suspect that trigger hybrid is bad. Does anyone know the compatibility between hybrid numbers? The installed U150 hybrid is a

155 0239 02

and I have a donor 2465 with a trigger hybrid of

155 0239 01

with the pcb marked 155 0239 XX.

Is it safe to substitute the 01 for the 02?

Max

P.s., I assume it IS NOT SAFE to substitute the preamps since the numbers are not even close (165 2235 02 and 155 0235 00).

Re: Tek 465 no display

 

The voltage at the collector of Q1404 will show if the high voltage
inverter is working correctly. If it is low then there is no high
voltage output and the regulator is trying to drive the inverter to
full power.

You could also measure the anode of CR1427 which should be -150 volts.

On Fri, 15 Jan 2016 10:37:06 +0000 (UTC), you wrote:

HiI have just joined the group and would appreciate any advice to assist me in resolving a problem.The 465 has been in storage for several years and was working when last used.  It was originally used for computer troubleshooting and later for various radio hobby work.The problem is no display visible even when using the beam finder.The screen illumination and front panel indicators are working. Also trigger indicators follow input signals on ch1 & 2.  I have checked the following voltages with a DVM +110, +55, +15, +5 and -8 and all are OK. Fuse 1419 is OK.  I have also checked for ripple using the AC range of the DVM and all appears surprisingly good given the age of the caps.Unfortunately I do not have a second scope or any way of checking the HV as my DVM only allows 600v max.I have tried reseating the socketed transistors but no changeIf anyone has any ideas how I can proceed taking into account the restrictions of my available test kit it would be great.ThanksDave

Re: My New Me Tek 465M Scope

 

On Fri, 15 Jan 2016 15:55:03 +0000, you wrote:

On 15/01/2016 09:58, David @DWH [TekScopes] wrote:

At high frequecies the coupling capacitor increases the current into
the protection diodes or forward biased JFET gate so the input voltage
limit drops with frequency.
Quite a lot, 1000p is ~1.5 Ohms at 100MHz.

Gordon
It is practically a short.

The 465M specifications say +/- 5 volts at 100 MHz and +/- 10 volts at
1 MHz with a 0.01 microfarad coupling capacitor which is 10 times
larger than the 465B coupling capacitor.

+/- 5 volts is within the input range of the protection circuits so
that is no surprise. For the +/- 10 volt specification, the 51 ohms
of input resistance plays a major role in limiting the current into
the protection diodes.

SG5050 on EBay.de

 

See: <http://cgi.ebay.de/262246576299> I have no affiliation with the seller
and this is *way* more than I can afford.

Re: 576 revisited

Ed Breya
 

Yes, the light exposure can decrease the strike voltage, but I don't think it should cause any problems - you can experiment with it in subdued lighting to see, or shine a bright light on them to accentuate it.

In the original HVPS with the "bad" epoxy transformer, the two series neons lit up all of the time toward one end of the intensity pot. After I did the HVPS swap and looked closely, I saw that one of the neons had its electrodes bent so close together that they almost touch, so maybe it went at a lower voltage. I don't know if this was a defect or damage from handling somewhere along the line while it was still a single part - like maybe someone dropped it on the floor. These two neons are bigger than normal - about twice the electrode length as the common NE-2 style, so are relatively flimsy in comparison. It would probably still take a lot of gs, so I don't think the 576 could have been dropped hard enough and survived.

The "new" HVPS had some problems that I finally tracked down to either a bad solder joint or bad rectifiers in the 225V supply. I had pulled at least one end of almost every part in the HVPS circuit trying to diagnose it, with no luck, until I finally changed out those rectifiers - I put in Tek -0400- diodes I had on hand in place of the -0107- originals, and it worked. However, when I checked the old diodes, they seemed to be just fine. The neons in this one have never fired, under any conditions, even with bright (LED warm white, lots of lumens) garage lighting.

It's entirely possible that the real culprit was a bad solder joint somewhere that got inadvertently fixed while checking various parts. I replaced the diodes right after a rehooking a whole bunch of other stuff that was up in the air, and then it worked on the next turn-on. Those gold plated boards look nice but what a PITA to tin and resolder - I did everything from the top side of the board, and had only a crappy iron at this location. Now I've got a good one here for further work on this project.

Ed

Re: 7603 Strange HV Need Help

Robert Simpson
 

Progress!
I have a trace but...

Starting from the front panel intensity control, I measured OK all the way to the logic board. The control voltage would vary coming out of Q90A but not out of U99C. Checking around, I found pin ED, a blanking control, was stuck LO, near ground, Zero volts, and using another scope, no signal. It's stuck in blanking mode.

Un-plugging J2139 from the readout board allows a trace to show!

Note: there are some circuit errors in a couple of PDF manuals:
For the Z Axis shutdown, The 7603 his res from Manoman.SQHILL.com version reprint November 1977 has an error listing on the logic circuit, lower left as P61-3 which is really P39-1. Same for a standard res version.

The December 1984 manual shows 39-2, which is actually ground. It should be 39-1

39 comes from J2139 off the readout board.

Bob

Re: 576 revisited

Albert Otten
 

Hi Ed,

While I was doing those CRT beam current measurements I ran into a probably non-existent problem. When I switched the DMM from 2V range to 20V range the DMM display jumped from 0 V to 3.3 V, despite intensity was still set at minimum. Being afraid I had damaged something I immediately switched off the 576. After switching on again to do diagnostic measurements I noticed that the grid-kathode protection neons B885-B886 were on and stayed on. The voltage across the 140V zener D882 was only 120 V, so I concluded that D882 was open and that the initial overvoltage caused the neons to switch on. However an in situ test of D882 showed that this zener was still good. But then a sufficient increase of the Intensity pot should force the neons to switch off again and return the 576 to normal operation; such indeed appeared to be the case.
In hindsight I think that when the HV cover and the 576 side panel are removed the circuit around the neons is very sensitive to noise signals from outside. Once fired the neons stay on when intensity is set near minimum. Maybe normally this also happens once and a while but goes unnoticed.
Did you ever encounter this "problem"?

Albert



---In TekScopes@..., <aodiversen@...> wrote :

Not exactly your question Ed, but I measured beam current via DC voltage across R886, 27k. Ten steps, full screen width. Normal viewing brightness about 2 uA. Curves are already visible below 50 nA. Current could easily be cranked up above 100 uA (overflow at 2 V range).

310A mains connector

Malcolm Hunter
 

Hi,

Forgive my ignorance, but is the power socket on a Tek 310A simply a
reversed US plug? i.e. Can I use one of these as an alternative?

http://www.lowes.com/pd_83901-1571-PS5269-XCCV8_1z0yt4p__?productId=3236817&pl=1

Are these available in Europe?

Thanks,
Malcolm

Re: Brookhaven 'wall-of-teks' link

Craig Sawyers <c.sawyers@...>
 

from Tim P (UK)

this is what I meant (I posted same long ago; Craig, you are right !)

https://www.flickr.com/photos/brookhavenlab/8495993808
Thanks for the big version, Tim - I've saved that!

Craig

Re: Brookhaven 'wall-of-teks' link

Daniel Koller
 

Awesome cool! I was wondering what instrument they were being used for. By the age, it looks like it could have been the Alternating Gradient Synchrotron, and I was right. Here's the photo in context:


https://www.bnl.gov/about/history/accelerators.php

My humble RM503 was the beam monitor at the Rutgers Van de Graaf for many years. The control room was similar, but smaller and far fewer scopes!

Dan

Brookhaven 'wall-of-teks' link

Tim Phillips <tim@...>
 

from Tim P (UK)

this is what I meant (I posted same long ago; Craig, you are right !)

https://www.flickr.com/photos/brookhavenlab/8495993808

Re: Wall-to-wall Teks Apologies :-(

Craig Sawyers <c.sawyers@...>
 

from Tim P(UK)
sorry, everyone - I meant Brookhaven Labs. The link got lost .
The AGS control room had about 30 teks, lots of 555s. I'll try and find the
link.
About a third of the way down the page https://www.bnl.gov/about/history/accelerators.php

Craig

Re: Wall-to-wall Teks Apologies :-(

Craig Sawyers <c.sawyers@...>
 

from Tim P(UK)
sorry, everyone - I meant Brookhaven Labs. The link got lost .
The AGS control room had about 30 teks, lots of 555s. I'll try and find the link.
I think I have seen the image before - it was basically a wall full of 500-series scopes. Heaven
knows how much air conditioning they needed to cope!

Craig

Re: Wall-to-wall Teks Apologies :-(

Tim Phillips <tim@...>
 

from Tim P(UK)
sorry, everyone - I meant Brookhaven Labs. The link got lost .
The AGS control room had about 30 teks, lots of 555s. I'll try and find the link.

----- Original Message -----
From: "'Tim Phillips' tim@... [TekScopes]" <TekScopes@...>
To: <TekScopes@...>
Sent: Monday, January 18, 2016 10:46 AM
Subject: [TekScopes] Wall-to-wall Teks @ BNPL





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Yahoo Groups Links


Re: 1A4 plug-in on Big Bang

stefan_trethan
 

Helmut Singer is now in the movie business too. ;-)
<http://www.helmut-singer.de/stock/862374989.html>

ST

On Mon, Jan 18, 2016 at 2:48 PM, public@... [TekScopes]
<TekScopes@...> wrote:
In one of the recent "The Expanse" (Scifi on Syfy) episodes there was a
whole bunch of Tek 7000 plugins at the lair of a "data broker". They
were, of course, knocked over by the cop.

Cheers, Marian
On 18.01.2016 14:22, Dwayne Verhey yg@... [TekScopes] wrote:
On 17/01/2016 6:07 PM, Peter Hildebrandt petertech99h@...
[TekScopes] wrote:

Our life's work reduced to TV props ! kinda sad but better then nothing!
Pete
Look at it this way: your life's work is a cultural icon that has been
immortalized in celluloid.



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Posted by: public@...
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Yahoo Groups Links


Re: 1A4 plug-in on Big Bang

Marian B
 

In one of the recent "The Expanse" (Scifi on Syfy) episodes there was a
whole bunch of Tek 7000 plugins at the lair of a "data broker". They
were, of course, knocked over by the cop.

Cheers, Marian

On 18.01.2016 14:22, Dwayne Verhey yg@... [TekScopes] wrote:
On 17/01/2016 6:07 PM, Peter Hildebrandt petertech99h@...
[TekScopes] wrote:

Our life's work reduced to TV props ! kinda sad but better then nothing!
Pete
Look at it this way: your life's work is a cultural icon that has been
immortalized in celluloid.

Re: 1A4 plug-in on Big Bang

Dwayne Verhey <yg@...>
 

On 17/01/2016 6:07 PM, Peter Hildebrandt petertech99h@... [TekScopes] wrote:

Our life's work reduced to TV props ! kinda sad but better then nothing!
Pete
Look at it this way: your life's work is a cultural icon that has been immortalized in celluloid.

Re: Wall-to-wall Teks @ BNPL

stefan_trethan
 

= UK equiv. of NIST

On Mon, Jan 18, 2016 at 12:37 PM, Stefan Trethan <stefan_trethan@...> wrote:
British National Physical Laboratory

On Mon, Jan 18, 2016 at 11:48 AM, Malcolm Hunter
malcolm.r.hunter@... [TekScopes] <TekScopes@...>
wrote:
Buy Now Pay Later?







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Posted by: Malcolm Hunter <malcolm.r.hunter@...>
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Yahoo Groups Links


Re: Wall-to-wall Teks @ BNPL

stefan_trethan
 

British National Physical Laboratory

On Mon, Jan 18, 2016 at 11:48 AM, Malcolm Hunter
malcolm.r.hunter@... [TekScopes] <TekScopes@...>
wrote:

Buy Now Pay Later?







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Posted by: Malcolm Hunter <malcolm.r.hunter@...>
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Yahoo Groups Links


Re: Wall-to-wall Teks @ BNPL

Malcolm Hunter
 

​Buy Now Pay Later?​