Date   

Re: Need obsolete IC

Scott
 

--- In TekScopes@..., "Tom Miller" <tmiller@...> wrote:

There are several BINs on ebay now. Just search "ca3096".

Tom

----- Original Message -----
From: Robert
To: TekScopes@...
Sent: Sunday, September 26, 2010 8:06 AM
Subject: [TekScopes] Need obsolete IC



Good morning all,

Does anyone have or know of a source for a CA3096AE-17 (Tek # 156-1381-00 originally made by RCA, used in 2215 scope "A13 Alternate Sweep Board", U648) general purpose high voltage silicon transistor array? I know the "A" means, parameter matching. I don't know what the "E" or "17" mean. I have searched Sphere and the usual Internet sites. I am down to the "brokers", and I wont go there. Intersil suggests an HFA3096 as a possible substitute but it's major electrical specifications are much lower than the CA version. I could of coped with the package difference with an adaptor.

Bob Curran
Try here:

http://www.ceitron.com/semi/semi.phtml?part=CA3096


Re: Missing Time BAse on Tektronix 214

Tom Miller <tmiller@...>
 

The 5.6 volts should be slightly low. It is from a 15 ohm decoupling RC circuit. R-401 & C-491.
 
As suggested, check all the caps. Tantalums are known to short or get very leaky.
 
Tom
 
 
 
 
 

----- Original Message -----
Sent: Sunday, September 26, 2010 4:25 PM
Subject: [TekScopes] Re: Missing Time BAse on Tektronix 214

 

Once again, with correct formatting (third try):

Lars Heineken>  writes:

  >  >  Sorry for the long delay, I had to wait until the weekend to continue
  >  >  working on the sweep generator.
  >  >  What has been discovered so far:
  >  >
  >  >     * All reference voltages are OK.
  >  >     * Blanking signal not present.
  >  >     * Horizontal signal not present (except on X/Y).
  >  >
  >  >     * The sweep generator used in the Tektronix 214 (U370) is:
  >  >       Tek Hybrid, 155-0048-00, MICROCIRCUIT,DI:TRIG&  SWEEP AMPL
  >  >       It creates a sawtooth signal (working as an integrator) based on
  >  >       the DIV/SEC knob.
  >  >     * The R/C pairs selected by the SEC/DIV knob are OK.
  >  >
  >  >  It looks like a defective U370 but I'm unsure how to verify that
  >  >  without a replacement :-(

  >  I'm still a newbie when it comes to electronics in general and scope
  >  r epair in particular.  However, undaunted, I downloaded and
  >  eyeballed the manual for the 214...

  >  It does make sense, logically, what you say, since a blown U370
  >  would cause a lack of unblanking and horizontal signals.  OTOH,
  >  isn't the U370 the only thing that feeds the horizontal signal to
  >  the the paraphase amp, U105?  If it was blown, you'd get no
  >  horizontal in *either* XY or X/t modes.

This is definitely a point. After I removed U370, there was no display

at all :-)



  >  Since caps tend to fail, I'd check the nearby caps a s well -- C372,
  >  C373, C374, C376, C378 -- either in circuit or out.

Testing them in circuit gave me some weird results. I'm going to

check back on them tomorrow. (PS: These capacitors are of the Tantal
type, so they shouldn't fail too easy, but I'm not an expert).


  >  Likewise, the input -- throw a signal at Ch-1, in auto-trigger
  >  mode, is there signal on R442?

Yes, as R442 leads to pin 1 of U370 (via S345).



  >  So I wonder, did you confirm by probing on the U370 output to see if
  >  anything is coming out?  Figure 9-3 has expected waveforms and pins.

So far I have checked the following pins of U370:

*  1 Trigger input: Identical to input signal, but amplified  (OK).< br>

*  2       ?      : -1.70V DC, no ripple  (OK).
*  3     Ground   :  0.00V DC, GND        (OK).
*  4: Blanking out: -4,43V DC, no signal  (*fail*). BAD
*  5: Sweep calib.: -1.00V DC, no signal  (OK).
*  6:      ?      :  2.06V DC, no signal, 17MHz ripple  (*fail*).
*  7: Single SWP  :  3.75V DC, no signal  (*fail*)
*  8: Horiz. out  : -0.20V DC, no signal  (*fail*)
*  9: Amp. input  :  1.80V DC, no signal, decreases to 1.4VDC when
                                            measuring  (?)
* 10:      ?      : -0.007V DC, no signal  (?)      Bad
* 11: +5.6V supl. :  5.20V DC, no signal  (OK?)  OK
                       Interestingly, this should be the +5.6V reference
                       voltage (Note: reference voltage from power
         ;               supply is at 5.6V, but this pin isn't).
* 12: -5.6V supl. : -5.18V DC, no signal  (OK?)  OK
                       Interestingly, this should be the -5.6V reference
                       voltage (Note: reference voltage from power
                       supply is at -5.6V, but this pin isn't).
* 13: -3.8V supl. : -3.82V DC, no signal  (OK)
* 14: +2.4V supl. :  2.98V DC, no signal  (OK?)  OK
                       As this voltage is taken from the -5.6V supply
                       measured at -5.18V (pin 12), this might be the
                       reason for being 0.5V off.
* 15: Sing. SWP In: -4.42V DC, no signal  (*fail*)
                       Does not change when closing/opening SW375
* 16: Slope       :  4.66V DC, no signal (?)
                       When watching the pin with an oscilloscope,
                        it acts like it's floating without GND reference.
                       As it's only coupled via small capacitor this
                       might be alright?

In summary, there's a lot of strange this going around U370. What

irritates me is the strange 5.6V reference voltage, but the slight
offset shouldn't cause such a havoc..

Best regards and hoping for further hints
:-),

Lars.



Re: Re-lettering push buttons (was problems with 465 etc) [1 Attachment]

Leon Robinson
 

Ben,

If you hadn't said anything I wouldn't know it.

Leon     K5JLR

Political Correctness is a Political Disease. K5JLR


--- On Sun, 9/26/10, Ben Clarke wrote:

From: Ben Clarke
Subject: [TekScopes] Re: Re-lettering push buttons (was problems with 465 etc) [1 Attachment]
To: TekScopes@...
Date: Sunday, September 26, 2010, 5:57 PM

 

At 22:22 26/09/2010, you wrote:
>Ben,
>Your process seems very interesting and may be useful in a number of
>situations. Do you have any photos to accompany your description?

Only of a finished example.
All the buttons shown in the attachment (providing it comes through
OK) have been produced this way.
They are not quite as skewed as they look in the photo, but a couple
are slightly off centre. I've got better since doing these!

Ben


Re: Re-lettering push buttons (was problems with 465 etc)

benclarke_uk
 

At 22:22 26/09/2010, you wrote:
Ben,
Your process seems very interesting and may be useful in a number of situations. Do you have any photos to accompany your description?
Only of a finished example.
All the buttons shown in the attachment (providing it comes through OK) have been produced this way.
They are not quite as skewed as they look in the photo, but a couple are slightly off centre. I've got better since doing these!

Ben


7854 self test...

Goran <goran.krusell@...>
 

Hello group,
when I switch on my 7854 the fan starts running, the power lamp turns on, the graticule is on but the self test never begins. Is this a known behaviour? Anything to do with ROMs? Where do I start looking?

Göran


Re: Re-lettering push buttons (was problems with 465 etc)

Frank P
 

Ben,
Your process seems very interesting and may be useful in a number of situations. Do you have any photos to accompany your description?


Thanks.

Frank P.


Tek 465 vertical preamp minor problem (amplitude to low for calibration)

Göran Krusell <goran.krusell@...>
 

Dennis,
something is wrong in the R83 vicinity. The upper end of R83 shall have signal but not the lower end since this point is a low impedance current input into Q86. The amplifier gain is based on having a voltage difference across R83 - but in this case you have not. Delta_V/R83 shall be your signal current. Try to check the passive components R75 to R93 and see what you find.

Göran


Re: Need obsolete IC

teamlarryohio
 

The 2213 & 2215 were born around 1981, and are not in the 93 catalog.
I *think* they (or the 'A' versions) were still in production when I left
in 86. I'd guess they may be supported on a best effort basis, given
it's a 30 year old design. I can't speak to the 222X's. They were after
my time.
-ls-

JanRwl@... wrote:

In a message dated 9/26/2010 7:06:18 A.M. Central Daylight Time,
rwcurranjr@... writes:

Does anyone have or know of a source for a CA3096AE-17 (Tek # 156-1381-00
originally made by RCA, used in 2215 scope <<
All this fuss for a REASONABLY-recent Tek part! What about asking Tek in
Beaverton? Don't they "back up" their products? I HOPE so, as I have a
seldom-fire-up 2225, bought new, just about the time CRT's went into the Dark
Ages, and so far, it's perfect. (Will it become a collectors' item???)


WTB PG-506/506A

Rich Miller
 

Hello:

 

I am looking for a PG-506 or 506A preferably with mainframe. I am not too concerned with cosmetic condition, but not looking to do repair work. Please respond directly to av8torrich@....

 

 

Rich


Re: Missing Time BAse on Tektronix 214

lars.heineken@ymail.com <Lars.Heineken@...>
 

Once again, with correct formatting (third try):

Lars Heineken>  writes:

  >  >  Sorry for the long delay, I had to wait until the weekend to continue
  >  >  working on the sweep generator.
  >  >  What has been discovered so far:
  >  >
  >  >     * All reference voltages are OK.
  >  >     * Blanking signal not present.
  >  >     * Horizontal signal not present (except on X/Y).
  >  >
  >  >     * The sweep generator used in the Tektronix 214 (U370) is:
  >  >       Tek Hybrid, 155-0048-00, MICROCIRCUIT,DI:TRIG&  SWEEP AMPL
  >  >       It creates a sawtooth signal (working as an integrator) based on
  >  >       the DIV/SEC knob.
  >  >     * The R/C pairs selected by the SEC/DIV knob are OK.
  >  >
  >  >  It looks like a defective U370 but I'm unsure how to verify that
  >  >  without a replacement :-(

  >  I'm still a newbie when it comes to electronics in general and scope
  >  repair in particular.  However, undaunted, I downloaded and
  >  eyeballed the manual for the 214...

  >  It does make sense, logically, what you say, since a blown U370
  >  would cause a lack of unblanking and horizontal signals.  OTOH,
  >  isn't the U370 the only thing that feeds the horizontal signal to
  >  the the paraphase amp, U105?  If it was blown, you'd get no
  >  horizontal in *either* XY or X/t modes.

This is definitely a point. After I removed U370, there was no display

at all :-)



  >  Since caps tend to fail, I'd check the nearby caps as well -- C372,
  >  C373, C374, C376, C378 -- either in circuit or out.

Testing them in circuit gave me some weird results. I'm going to

check back on them tomorrow. (PS: These capacitors are of the Tantal
type, so they shouldn't fail too easy, but I'm not an expert).


  >  Likewise, the input -- throw a signal at Ch-1, in auto-trigger
  >  mode, is there signal on R442?

Yes, as R442 leads to pin 1 of U370 (via S345).



  >  So I wonder, did you confirm by probing on the U370 output to see if
  >  anything is coming out?  Figure 9-3 has expected waveforms and pins.

So far I have checked the following pins of U370:

*  1 Trigger input: Identical to input signal, but amplified  (OK).
*  2       ?      : -1.70V DC, no ripple  (OK).
*  3     Ground   :  0.00V DC, GND        (OK).
*  4: Blanking out: -4,43V DC, no signal  (*fail*).
*  5: Sweep calib.: -1.00V DC, no signal  (OK).
*  6:      ?      :  2.06V DC, no signal, 17MHz ripple  (*fail*).
*  7: Single SWP  :  3.75V DC, no signal  (*fail*)
*  8: Horiz. out  : -0.20V DC, no signal  (*fail*)
*  9: Amp. input  :  1.80V DC, no signal, decreases to 1.4VDC when
                                            measuring  (?)
* 10:      ?      : -0.007V DC, no signal  (?)
* 11: +5.6V supl. :  5.20V DC, no signal  (OK?)
                       Interestingly, this should be the +5.6V reference
                       voltage (Note: reference voltage from power
                       supply is at 5.6V, but this pin isn't).
* 12: -5.6V supl. : -5.18V DC, no signal  (OK?)
                       Interestingly, this should be the -5.6V reference
                       voltage (Note: reference voltage from power
                       supply is at -5.6V, but this pin isn't).
* 13: -3.8V supl. : -3.82V DC, no signal  (OK)
* 14: +2.4V supl. :  2.98V DC, no signal  (OK?)
                       As this voltage is taken from the -5.6V supply
                       measured at -5.18V (pin 12), this might be the
                       reason for being 0.5V off.
* 15: Sing. SWP In: -4.42V DC, no signal  (*fail*)
                       Does not change when closing/opening SW375
* 16: Slope       :  4.66V DC, no signal (?)
                       When watching the pin with an oscilloscope,
                       it acts like it's floating without GND reference.
                       As it's only coupled via small capacitor this
                       might be alright?

In summary, there's a lot of strange this going around U370. What

irritates me is the strange 5.6V reference voltage, but the slight
offset shouldn't cause such a havoc..

Best regards and hoping for further hints
:-),

Lars.



Tek 465 vertical preamp minor problem (amplitude to low for calibration)

Dennis Dingeldein
 

After having brought back my Tek 465 to live, I went through the first part of the
calibration procedure. Beam is now sharp. Channel 1 vertical amp is also calibrated.

During procedure for channel 2, I found that I could not adjust the amplitude of the 300 mV
test signal to use 3 graticules in the 100mV range. Maximum wI got as about 2 graticules, looking like
200mV. Hm. I could not found any pot besides CH2 GAIN CAL to improve the level displayed. The
vertical output amp which has an overall output level in the non-IC-version was also not helpful in
my case because I have the IC-version of the vertical output amp without that pot.

So I moved from calibration mode back to repair mode :-(

I tracked the problem down to the following situation by comparing signals from both channels.

Signal is fine until TP2 (ch1) and TP12 (ch2).

For ch1, signal stays fine at TP3 and TP4 and after that. ch1 is fine at all places.

For ch2, signal amplitude is ok at TP13, but signal is very noisy. At TP14, I have only noise,
no signal visible.

Conclusion up to here: The problem is somewhere between TP12 and TP13/14.

I changed the transistor pairs involved:

Changing Q32/36 with Q82/86 has no effect. So Q82/86 seem ok.

Changing Q42/44 with Q92/94 has no effect. So Q42/44 seem ok.

Changing Q102/104 with Q202/204 has no effect. So Q102/104 seem ok.

Conclusion up to here: transistors involved seem not to be responsible for the problem.

Next I measured at the well-working ch1 the signal at Collector of Q32 and at Emitter of Q36.
Both have ~170mV and nice-looking waveforms.

I compared this to the situation in the channel 2 at Q82 and Q86:
I found there only ~80mV, signal waveform looks ok.
So the amplitude is to low in channel 2 at these points.
(Yes I am sure that I selected the .1V range)

Then I observed all DC voltage levels at transistors Q32,36,82,86, all look very good.

Continuing the search, I found two additional things:

At ch1, I can measure the input signal only at upper end of R33, at lower end I see no signal.
At ch2, I can see the signal at both ends of R83. This is a difference between both channels, but I do
not understand why.

At the right side of R35 and R85 (=in both channels) I measure only ~3,3V, the manual
mentiones 4,2V there. Because it's in both channels, I think this does not produce the problem.

The funny thing here is that the ch2 preamp is basically amplifying the signal, so it does what it should.
But the amplitude is to low. And this is not related to an active component. So there remain condensators,
resistirs, diodes (including capacity diodes CR34/84, a NTC(?) RT39 and a thing called FED (CR39) looking
like an germanium diode...


Re: problems repairing a 465 (Calibration questions)

Dennis Dingeldein
 

Hello Doug,
the calibration procedure is very well described in the service manual. You can download the manual (If you do not already have it) from the following link:

http://bama.edebris.com/manuals/tek/

They have manuals for both 465 and 465B. Section 6 of the manual decsribes the calibration procedure (~50 pages).

The service manual is also here at the TekGroup:
http://tech.groups.yahoo.com/group/TekScopArc/files/

I was interrupted in my calibration at the channel 2 preamp calibration, but this can be found in another post from me :-)

Dennis

--- In TekScopes@..., Douglas Ho <dho695@...> wrote:


Hello Dennis,

I have been reading your blog, very interesting. I also have a working 465 and I think it is about time to do calibration. You did mention about calibration. Can you give me a shot cut or a simplest way to do it myself.

Doug

To: TekScopes@...
From: dennis_4011@...
Date: Thu, 23 Sep 2010 13:00:15 +0000
Subject: [TekScopes] Re: RE:problems repairing a 465 (large ripple voltage and CH2 failure) / z axis




























Göran,

there is really a shortcut between Emitter and Base of Q1472.



I checked carefully the easy accessible side of the interface board, everything there was ok. To check the other side, the interface board has to be removed. This lasts some hours and I've already done that some days ago :-(((



So I decided to do an initial approach with less effort by isolating the part of the PCB that connects B and E by disconnecting all components that are soldered to the "Emitter-Solder-Island" of Q1472. These were:

- R1472

- C1476

- CR1472



Then I inserted Q1472 with Emitter not connected to the PCB and wired all open ends together with some temporary wires.



And: TADA!!! I have a very bright screen now, can vary intensity in a wide range and I do not see beam return traces on the display anymore.

Wow, that was the last bug, a shortcut on the inner side of the PCB!



So electronically everything seems ok now. Beam is not very sharp but very bright :-) and I think I will go though the calibration process and can improve this considerably.

The scope was repaired (or try-to-repaired) by someone else before, I could see that at several places inside. So I guess some pots inside have also been touched and can be corrected by doing calibration.



One Question left: The shortcut is on the inner side on the interface board. Is there an easier way to get to that area without removing the whole interface board? Removing the interface board is hard work...



Next I will check where to get the two broken Knobs:

- Volts/Div Knob with Scale for Channel 2

- Slope Level Outer Knob

(- "A Lock Knobs" Pressbutton has no text on it anymore)



So many many thanks, Göran, you were virtually holding my hands going through the 465!!! Thanks also to the other ones who helped with their knowledge!!!



Dennis



--- In TekScopes@..., Göran Krusell <goran.krusell@> wrote:

Dennis,
Your current calculation is quite correct!! I(R1476) = 6.09mA, I(R1478) = 2.59mA, I(Q1478) = 3.5mA and this may very well explain why it runs hot, 350mW, if the can is small size.
There seems to be a short between base and emitter of Q1472 which may explain why there is no collector current through Q1472, you measured 0V at the collector. If there is no collector current through Q1472 the anode of CR1472 may rise to a higher voltage. Check the soldering around Q1472.
Göran


Re: Manuals for a Tek 2335

MIKE DURKIN <Patriot121@...>
 

I have a vertical deflection issues on a 2336YA .....

Moving the vertical up and down doesn't help usually. After it warms it works (aprox 5min) beam is usually at the bottom and beam finder does work (beam shows up at the bottom 1/4)

I swapped CH1 for CH2 vertical control with no change in issue.

Mike




To: TekScopes@...
From: dcasey@...
Date: Sun, 26 Sep 2010 13:12:24 -0500
Subject: Re: [TekScopes] Re: Manuals for a Tek 2335

 

Yes, I have a full manual with fold out schematics, but for the 2336, not the 2335. I believe they are almost identical but not entirely. So again, if you want something simple looked up or a macro-mode photo of a page or two, I can help.
 
Dave Casey
Sent from my PC

----- Original Message -----
From: Frank P
Sent: Sunday, September 26, 2010 10:08 AM
Subject: [TekScopes] Re: Manuals for a Tek 2335

 
Dave,
Does your information include the schematics?

Frank P.

--- In TekScopes@..., "Dave Casey" wrote:
>
> I have hardcopy 2336 manuals if there's something you need me to look up. If you need extensive information, you should probably just invest in a PDF from Artek.
>
> Dave Casey
> Sent from my PC
> ----- Original Message -----
> From: Frank P
> To: TekScopes@...
> Sent: Saturday, September 25, 2010 9:40 PM
> Subject: [TekScopes] Manuals for a Tek 2335
>
>
>
> Does anyone have the manuals for a Tek 2335 (BAMA doesn't)?
>
> Thanks.
>




Re: problems repairing a 465 (Calibration questions)

Angela(Eastman) Ho
 

Hello Dennis,

I have been reading your blog, very interesting.  I also have a working 465 and I think it is about time to do calibration.  You did mention about calibration.  Can you give me a shot cut or a simplest way to do it myself.

Doug


To: TekScopes@...
From: dennis_4011@...
Date: Thu, 23 Sep 2010 13:00:15 +0000
Subject: [TekScopes] Re: RE:problems repairing a 465 (large ripple voltage and CH2 failure) / z axis

 
Göran,
there is really a shortcut between Emitter and Base of Q1472.

I checked carefully the easy accessible side of the interface board, everything there was ok. To check the other side, the interface board has to be removed. This lasts some hours and I've already done that some days ago :-(((

So I decided to do an initial approach with less effort by isolating the part of the PCB that connects B and E by disconnecting all components that are soldered to the "Emitter-Solder-Island" of Q1472. These were:
- R1472
- C1476
- CR1472

Then I inserted Q1472 with Emitter not connected to the PCB and wired all open ends together with some temporary wires.

And: TADA!!! I have a very bright screen now, can vary intensity in a wide range and I do not see beam return traces on the display anymore.
Wow, that was the last bug, a shortcut on the inner side of the PCB!

So electronically everything seems ok now. Beam is not very sharp but very bright :-) and I think I will go though the calibration process and can improve this considerably.
The scope was repaired (or try-to-repaired) by someone else before, I could see that at several places inside. So I guess some pots inside have also been touched and can be corrected by doing calibration.

One Question left: The shortcut is on the inner side on the interface board. Is there an easier way to get to that area without removing the whole interface board? Removing the interface board is hard work...

Next I will check where to get the two broken Knobs:
- Volts/Div Knob with Scale for Channel 2
- Slope Level Outer Knob
(- "A Lock Knobs" Pressbutton has no text on it anymore)

So many many thanks, Göran, you were virtually holding my hands going through the 465!!! Thanks also to the other ones who helped with their knowledge!!!

Dennis

--- In TekScopes@..., Göran Krusell wrote:
>
> Dennis,
>
> Your current calculation is quite correct!! I(R1476) = 6.09mA, I(R1478) = 2.59mA, I(Q1478) = 3.5mA and this may very well explain why it runs hot, 350mW, if the can is small size.
>
> There seems to be a short between base and emitter of Q1472 which may explain why there is no collector current through Q1472, you measured 0V at the collector. If there is no collector current through Q1472 the anode of CR1472 may rise to a higher voltage. Check the soldering around Q1472.
>
> Göran
>



Re: Manuals for a Tek 2335

MIKE DURKIN <Patriot121@...>
 

Sad .. its just a User Manual .. no service manual for the 2335 - or what im looking for a 2336YA ..




To: TekScopes@...
From: jayw_comark@...
Date: Sun, 26 Sep 2010 10:36:49 +0000
Subject: [TekScopes] Re: Manuals for a Tek 2335

 
Hi Frank,

You can find one here:
http://128.238.9.201/~kurt/manuals/manuals/Tektronix/

Jay

--- In TekScopes@..., "Frank P" >
> Does anyone have the manuals for a Tek 2335 (BAMA doesn't)?
>
> Thanks.
>



Re: Manuals for a Tek 2335

Dave Casey <dcasey@...>
 

Yes, I have a full manual with fold out schematics, but for the 2336, not the 2335. I believe they are almost identical but not entirely. So again, if you want something simple looked up or a macro-mode photo of a page or two, I can help.
 
Dave Casey
Sent from my PC

----- Original Message -----
From: Frank P
Sent: Sunday, September 26, 2010 10:08 AM
Subject: [TekScopes] Re: Manuals for a Tek 2335

 

Dave,
Does your information include the schematics?

Frank P.

--- In TekScopes@..., "Dave Casey" wrote:
>
> I have hardcopy 2336 manuals if there's something you need me to look up. If you need extensive information, you should probably just invest in a PDF from Artek.
>
> Dave Casey
> Sent from my PC
> ----- Original Message -----
> From: Frank P
> To: TekScopes@...
> Sent: Saturday, September 25, 2010 9:40 PM
> Subject: [TekScopes] Manuals for a Tek 2335
>
>
>
> Does anyone have the manuals for a Tek 2335 (BAMA doesn't)?
>
> Thanks.
>


Shanon Hill Contact info

Artekmedia <manuals@...>
 

Does anyone have Shanon Hills (manoman.sqhill.com) email address?

Please replay direct to manuals@...

Dave

--
Dave& Lynn Henderson
Manuals@...
www.Artekmedia.com
PO Box 175
Welch,MN 55089


Re: Need obsolete IC

JanRwl@...
 

In a message dated 9/26/2010 7:06:18 A.M. Central Daylight Time, rwcurranjr@... writes:
Does anyone have or know of a source for a CA3096AE-17 (Tek # 156-1381-00 originally made by RCA, used in 2215 scope <<
All this fuss for a REASONABLY-recent Tek part!  What about asking Tek in Beaverton?  Don't they "back up" their products?  I HOPE so, as I have a seldom-fire-up 2225, bought new, just about the time CRT's went into the Dark Ages, and so far, it's perfect.   (Will it become a collectors' item???)        Jan Rowland


Re: 2440 CCD Problem - HELP!

Rich Miller
 

Hi Victor:

 

I did see that warning, and had both the internal and an external fan blowing. I don't think the original muffin fan was "cutting the mustard", so I am now utilizing a large blower. This seems to have solved the problem with regards to cooling issue. The CCD hybrids are now staying very cool, and if I had to guess, cooler than when the chassis is installed.

 

Thanks for the help!

 


Rich

 

From: TekScopes@... [mailto:TekScopes@...] On Behalf Of gwangju3
Sent: Sunday, September 26, 2010 10:04 AM
To: TekScopes@...
Subject: [TekScopes] Re: 2440 CCD Problem - HELP!

 

 

The warning in the SM is that if you remove the case you must have both the built in fan running and another fan with the same CFM rating blowing on the CCDs.

--Victor


Re: HV supply tektronix 535A

guy allo
 

Hi,
Hi
You have a stable voltage -161V on the grid of V814B (pin 2).
 
How is the voltage on C845 when you turn R856 (Focus)? is it always -1350V?

 

From: majefepe
To: TekScopes@...
Sent: Sat, September 25, 2010 9:06:27 PM
Subject: [TekScopes] Re: HV supply tektronix 535A

Hi, sorry for my


--- In TekScopes@..., guy allo wrote:
>hi, actually the high voltage is +8650 v. The comparator is a 12AU7A valve and 6au6 for 100v. I downloaded the cathode voltage up to-1200v and then went up to -1400V. but in the grid I have always comparator-161v. I checked the circuit, but always I have this voltage. so that any variation in load does not affect this tension, is always fixed. Any idea? Thank you.
> Hi,
> I have one one my bench.
> Which high voltage supply ? CRT high voltage +8650Volts?
> What is the comparator valve number?  V664 for the +100V supply?
> Tek508
>
>
>
> ________________________________
> From: majefepe
> To: TekScopes@...
> Sent: Sat, September 25, 2010 5:57:29 PM
> Subject: [TekScopes] HV supply tektronix 535A
>
> I need help, I have a tektronix 535A and I have a problem at the source of high
> voltage, the comparator output is always 160 volts, the output is independent of
> the cathode voltage, which does not stabilize this tension, which can be the
> problem? changed and high voltage capacitors and comparator valve to no avail.
> The resistance of the comparator are good, what can be the problem? Thank you
> all for your help.
>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>




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