Date   

Re: Special Offer from Peter Keller to TekScopes Members: The Cathode Ray Tube, Technology, History, and Applications"

n4buq
 

I may be misremembering that. I recall looking at a color display and seeing the dots but that may not have been my Trinitron. Sorry for the confusion.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "snapdiode via groups.io" <snapdiode=yahoo.com@groups.io>
To: TekScopes@groups.io
Sent: Monday, November 16, 2020 11:58:35 AM
Subject: Re: [TekScopes] Special Offer from Peter Keller to TekScopes Members: The Cathode Ray Tube, Technology,
History, and Applications"

I'm a bit confused about the Trinitron having "dots", the Trinitron relies on
stripes and the mask is an aperture grille.






Re: Special Offer from Peter Keller to TekScopes Members: The Cathode Ray Tube, Technology, History, and Applications"

Chuck Harris <cfharris@...>
 

The trinitron works in much the same way as the shadow mask
CRT's, with their triangular gun orientation, that GE and others
developed.

The major difference is the trinitron uses a common gun, with three
horizontally spaced, cathodes.... one for each of the red, blue, and
green phosphor colors.

At the screen is a grill made up of high tension parallel wires that
go from the top of the screen to the bottom. There is usually a couple
of wires welded horizontally at various placements to keep the high
tension wires from vibrating much.

The common gun has three horizontally spaced RGB cathodes, and the
alignment of the beams is arranged so that they travel at slightly
different angles, converging at the slots formed by the high tension
shadow mask wires.

Any beam that can pass through a slot between the wires can only illuminate
the appropriate stripe of color phosphor. When it is in a position where
it could illuminate a wrong phosphor color, it is blocked by the shadow
wire.

-Chuck Harris

n4buq wrote:

Hi Tom,

My question is probably quite simple but, like I said, I'm not finding a good answer.

As I understand it (and from personal observation when I had a Trinitron TV and I'm primarily wondering about this type of CRT but the question probably applies to others), the screen has groupings of RBG phospher dots and the RGB guns "activate" those dots as needed; however, what I'm not understanding is how a given gun "activates" a given dot. Is a particular phosphor dot sensitive to a property of one of the color guns such that a blue dot ignores a red gun, etc.? If so, then I can somewhat understand it but I'm wondering if I'm way off in that assumption.

The various sites just seem to indicate there are three guns, each of which magically cause a given color to appear but it's not explained how a single color gun causes a corresponding dot to glow without affecting the ones around it.

(Hope that made sense...)

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Tom Lee" <tomlee@ee.stanford.edu>
To: TekScopes@groups.io
Sent: Monday, November 16, 2020 11:27:46 AM
Subject: Re: [TekScopes] Special Offer from Peter Keller to TekScopes Members: The Cathode Ray Tube, Technology,
History, and Applications"

Hi Barry,

Pete's book mainly covers electrostatically deflected crts. Except for
some very early models, TVs used magnetically deflected crts (to allow
large screens without absurd set depths). The guns are similar, but the
deflection methods are very different because of the different
optimization objectives.

--Tom

--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
http://www-smirc.stanford.edu

On 11/16/2020 07:18, n4buq wrote:
Does anyone know whether this book covers CRTs that were used for color TVs
(and other color displays)? I ask because I'm not finding good
information on how those work.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Dennis Tillman W7pF" <dennis@ridesoft.com>
To: TekScopes@groups.io
Sent: Monday, November 16, 2020 12:15:11 AM
Subject: Re: [TekScopes] Special Offer from Peter Keller to TekScopes
Members: The Cathode Ray Tube, Technology,
History, and Applications"

Hi Chris,
I don't expect any problems shipping this to Germany.

One correction:
This offer is strictly between Peter Keller and individual members of the
group. I did offer to act as the go-between because I thought there might
be
some interest and because I understood how "sensitive" our members are to
price. I was also hoping this would give Peter some well-deserved cash as
we
get close to the holidays.

So I told Peter I thought I might be able to pass along 10 orders for his
book. When he said OK I notified TekScopes. That was 36 hours ago. I have
orders for over 50 of his books as of this moment.

This brings back memories of when I asked for small donations to pay
Groups.io the annual fee for hosting TekScopes back at the beginning of
the
year. Somebody please remind me the next time I think up something like
this
to think twice about what happened the last two times I had a bright idea.
:)

Dennis Tillman W7pF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of
ChrisBeee
via groups.io
Sent: Sunday, November 15, 2020 8:47 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Special Offer from Peter Keller to TekScopes
Members: The Cathode Ray Tube, Technology, History, and Applications"

Hi Dennis,
I would be more than glad if I could support the group buy and get a copy
of
Peter's book, many thanks for making this possible! My only concern is if
you would ship to Germany too. I will send you a PM with my contact data.
Cheers
Chris







--
Dennis Tillman W7pF
TekScopes Moderator

















Re: Special Offer from Peter Keller to TekScopes Members: The Cathode Ray Tube, Technology, History, and Applications"

snapdiode
 

I'm a bit confused about the Trinitron having "dots", the Trinitron relies on stripes and the mask is an aperture grille.


Re: Special Offer from Peter Keller to TekScopes Members: The Cathode Ray Tube, Technology, History, and Applications"

Dave Voorhis
 

On 16 Nov 2020, at 17:43, n4buq <n4buq@knology.net> wrote:

Hi Tom,

My question is probably quite simple but, like I said, I'm not finding a good answer.

As I understand it (and from personal observation when I had a Trinitron TV and I'm primarily wondering about this type of CRT but the question probably applies to others), the screen has groupings of RBG phospher dots and the RGB guns "activate" those dots as needed; however, what I'm not understanding is how a given gun "activates" a given dot. Is a particular phosphor dot sensitive to a property of one of the color guns such that a blue dot ignores a red gun, etc.? If so, then I can somewhat understand it but I'm wondering if I'm way off in that assumption.

The various sites just seem to indicate there are three guns, each of which magically cause a given color to appear but it's not explained how a single color gun causes a corresponding dot to glow without affecting the ones around it.
The three beams are dynamically and statically aligned via a set of magnets and electromagnets arranged around the neck of the tube, in addition to the yoke coils that deflect the three beams together. The beams are aimed at a photo-etched perforated barrier called a shadow mask, which is either etched with holes (conventional colour CRT) or slots (Sony Trinitron) to further refine and align the beam. The combination of the static and dynamic deflection, plus the shadow mask, ensures that each colour gun only illuminates the relevant colour phosphor dots or bars on the face of the tube.

At least, that’s what I recall from about 40 years ago, which is when I last repaired colour televisions.


Re: Special Offer from Peter Keller to TekScopes Members: The Cathode Ray Tube, Technology, History, and Applications"

Colin Herbert
 

OK, I have a _very_ limited knowledge of colour CRTs, but I think the "magic" is called a "shadow-mask". The three electron guns are located in slightly different places ate the "gun" end of the tube and accelerate electrons to the phosphor screen. The shadow-mask has tiny holes in it in a matrix and the electron guns fire through these to only hit the three different colour phosphor spots that they are associated with. Does that make any sense?
Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of n4buq
Sent: 16 November 2020 17:43
To: TekScopes@groups.io
Subject: Re: [TekScopes] Special Offer from Peter Keller to TekScopes Members: The Cathode Ray Tube, Technology, History, and Applications"

Hi Tom,

My question is probably quite simple but, like I said, I'm not finding a good answer.

As I understand it (and from personal observation when I had a Trinitron TV and I'm primarily wondering about this type of CRT but the question probably applies to others), the screen has groupings of RBG phospher dots and the RGB guns "activate" those dots as needed; however, what I'm not understanding is how a given gun "activates" a given dot. Is a particular phosphor dot sensitive to a property of one of the color guns such that a blue dot ignores a red gun, etc.? If so, then I can somewhat understand it but I'm wondering if I'm way off in that assumption.

The various sites just seem to indicate there are three guns, each of which magically cause a given color to appear but it's not explained how a single color gun causes a corresponding dot to glow without affecting the ones around it.

(Hope that made sense...)

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Tom Lee" <tomlee@ee.stanford.edu>
To: TekScopes@groups.io
Sent: Monday, November 16, 2020 11:27:46 AM
Subject: Re: [TekScopes] Special Offer from Peter Keller to TekScopes Members: The Cathode Ray Tube, Technology,
History, and Applications"

Hi Barry,

Pete's book mainly covers electrostatically deflected crts. Except for
some very early models, TVs used magnetically deflected crts (to allow
large screens without absurd set depths). The guns are similar, but the
deflection methods are very different because of the different
optimization objectives.

--Tom

--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
http://www-smirc.stanford.edu

On 11/16/2020 07:18, n4buq wrote:
Does anyone know whether this book covers CRTs that were used for color TVs
(and other color displays)? I ask because I'm not finding good
information on how those work.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Dennis Tillman W7pF" <dennis@ridesoft.com>
To: TekScopes@groups.io
Sent: Monday, November 16, 2020 12:15:11 AM
Subject: Re: [TekScopes] Special Offer from Peter Keller to TekScopes
Members: The Cathode Ray Tube, Technology,
History, and Applications"

Hi Chris,
I don't expect any problems shipping this to Germany.

One correction:
This offer is strictly between Peter Keller and individual members of the
group. I did offer to act as the go-between because I thought there might
be
some interest and because I understood how "sensitive" our members are to
price. I was also hoping this would give Peter some well-deserved cash as
we
get close to the holidays.

So I told Peter I thought I might be able to pass along 10 orders for his
book. When he said OK I notified TekScopes. That was 36 hours ago. I have
orders for over 50 of his books as of this moment.

This brings back memories of when I asked for small donations to pay
Groups.io the annual fee for hosting TekScopes back at the beginning of
the
year. Somebody please remind me the next time I think up something like
this
to think twice about what happened the last two times I had a bright idea.
:)

Dennis Tillman W7pF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of
ChrisBeee
via groups.io
Sent: Sunday, November 15, 2020 8:47 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Special Offer from Peter Keller to TekScopes
Members: The Cathode Ray Tube, Technology, History, and Applications"

Hi Dennis,
I would be more than glad if I could support the group buy and get a copy
of
Peter's book, many thanks for making this possible! My only concern is if
you would ship to Germany too. I will send you a PM with my contact data.
Cheers
Chris







--
Dennis Tillman W7pF
TekScopes Moderator













Re: Tek 577 D1 storage adjustment questions.

Dave Voorhis
 

On 16 Nov 2020, at 17:08, Eric <ericsp@gmail.com> wrote:

I am working on some 577’s D1 storage curve tracers. I am trying to get a 178 working. So I need the storage tubes up and running. I do not have much experience with storage tubes hence the noob question. I think one of these units has been miss adjusted pretty badly, my problem Is I do not know which one. When I do the 6 minute startup as called for in the manual both units will get some glow bloom on the tubes. One is far dimmer then the other but both tubes have really good brightness so I do not believe that it is a tired tube. If I hit erase on both tubes they will blank as expected but the bright one will again go to full glow. At the full brightness the tube will not actually store anything as it looks like the glow is too bright. On the dimmer tube after the initial power up the tube will not bloom any more in storage mod and it will store a waveform however the “brightness control” must be all the way up. At minimum storage brightness it will store but it will only store at the edges.

So having minimal exposure to storage tubes is this normal behavior or is one or both miss adjusted? I can take some pictures if it will help. In the service manual it talks about adjusting the tubes but it does not say where the brightness control should be during the adjustment curious if anyone has insight on that as well.
I have a 577 D1 which is rather similar to your dimmer tube. It originally had an obviously failing CRT — dim to barely visible in non-store mode and double-peaking — but storage mode worked surprisingly well despite the dim trace.

I replaced the CRT with a used spare that came with the curve tracer. Now it’s bright and sharp in non-store mode but despite multiple attempts at tuning the storage settings per the service manual, it will only store if the intensity is turned up to be uncomfortably bright and the brightness control doesn’t appear to affect storage sensitivity, only the brightness of a stored trace.

I suspect either the replacement CRT has worn-out storage gubbins or is in some manner mismatched to the drive circuitry, or I’ve somehow repeatedly failed to correctly follow the service manual instructions.

Sorry, that’s obviously no help at all, but I’m hoping someone will chime in with knowledge that will help both of us.


Re: Special Offer from Peter Keller to TekScopes Members: The Cathode Ray Tube, Technology, History, and Applications"

n4buq
 

Hi Tom,

My question is probably quite simple but, like I said, I'm not finding a good answer.

As I understand it (and from personal observation when I had a Trinitron TV and I'm primarily wondering about this type of CRT but the question probably applies to others), the screen has groupings of RBG phospher dots and the RGB guns "activate" those dots as needed; however, what I'm not understanding is how a given gun "activates" a given dot. Is a particular phosphor dot sensitive to a property of one of the color guns such that a blue dot ignores a red gun, etc.? If so, then I can somewhat understand it but I'm wondering if I'm way off in that assumption.

The various sites just seem to indicate there are three guns, each of which magically cause a given color to appear but it's not explained how a single color gun causes a corresponding dot to glow without affecting the ones around it.

(Hope that made sense...)

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Tom Lee" <tomlee@ee.stanford.edu>
To: TekScopes@groups.io
Sent: Monday, November 16, 2020 11:27:46 AM
Subject: Re: [TekScopes] Special Offer from Peter Keller to TekScopes Members: The Cathode Ray Tube, Technology,
History, and Applications"

Hi Barry,

Pete's book mainly covers electrostatically deflected crts. Except for
some very early models, TVs used magnetically deflected crts (to allow
large screens without absurd set depths). The guns are similar, but the
deflection methods are very different because of the different
optimization objectives.

--Tom

--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
http://www-smirc.stanford.edu

On 11/16/2020 07:18, n4buq wrote:
Does anyone know whether this book covers CRTs that were used for color TVs
(and other color displays)? I ask because I'm not finding good
information on how those work.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Dennis Tillman W7pF" <dennis@ridesoft.com>
To: TekScopes@groups.io
Sent: Monday, November 16, 2020 12:15:11 AM
Subject: Re: [TekScopes] Special Offer from Peter Keller to TekScopes
Members: The Cathode Ray Tube, Technology,
History, and Applications"

Hi Chris,
I don't expect any problems shipping this to Germany.

One correction:
This offer is strictly between Peter Keller and individual members of the
group. I did offer to act as the go-between because I thought there might
be
some interest and because I understood how "sensitive" our members are to
price. I was also hoping this would give Peter some well-deserved cash as
we
get close to the holidays.

So I told Peter I thought I might be able to pass along 10 orders for his
book. When he said OK I notified TekScopes. That was 36 hours ago. I have
orders for over 50 of his books as of this moment.

This brings back memories of when I asked for small donations to pay
Groups.io the annual fee for hosting TekScopes back at the beginning of
the
year. Somebody please remind me the next time I think up something like
this
to think twice about what happened the last two times I had a bright idea.
:)

Dennis Tillman W7pF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of
ChrisBeee
via groups.io
Sent: Sunday, November 15, 2020 8:47 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Special Offer from Peter Keller to TekScopes
Members: The Cathode Ray Tube, Technology, History, and Applications"

Hi Dennis,
I would be more than glad if I could support the group buy and get a copy
of
Peter's book, many thanks for making this possible! My only concern is if
you would ship to Germany too. I will send you a PM with my contact data.
Cheers
Chris







--
Dennis Tillman W7pF
TekScopes Moderator













Re: Q122/222 Jfet J300 subs for 2215A scope ?

Jeff Kruth
 

I dont know if this helps, but I have a small stash of metal can J310 type.Jeff Kruth In a message dated 11/16/2020 9:35:56 AM Eastern Standard Time, charlesterrebonne@hotmail.com writes: 
thanks to all who replied - the 2215A scope is off the bench for now but Ill get back to it soon and will report when I get this working...I am almost at the point of sticking a high quality transistor socket there and just trying some other close to J300 specs Jfets I have on hand...FYI all the parts I have tried in the Q122/Q222 position in the scope : 2N3918, NTE133, k19, NTE132 tested good out of circuit...i have some more Jfet #s in my stock I need to try.

From the Tektronix replaceable parts reg. : 151-1124-00 = Siliconix J-2400...would'nt be surprised this was not a custom design but more likely tested/hand picked J300s jfets and assigned a Tektronix custom part# from Siliconix...searching Siliconix j-2400 brings up nothing...Id suspect most input boards from that 22xx series scopes came off the assembly line with "J300" marked Jfets in those Q122/222 positions..thanks


Re: Q122/222 Jfet J300 subs for 2215A scope ?

Tom Lee
 

Instead of sticking in a socket, just measure IDSS first. I posted the current range that will work.

You may still have a problem with the bias circuit. I've never run into a 22xx scope that was anywhere near as fussy about FETs as yours. That bias circuit is quite forgiving.

--Tom

--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
http://www-smirc.stanford.edu

On 11/16/2020 06:35, charlesterrebonne@hotmail.com wrote:
thanks to all who replied - the 2215A scope is off the bench for now but Ill get back to it soon and will report when I get this working...I am almost at the point of sticking a high quality transistor socket there and just trying some other close to J300 specs Jfets I have on hand...FYI all the parts I have tried in the Q122/Q222 position in the scope : 2N3918, NTE133, k19, NTE132 tested good out of circuit...i have some more Jfet #s in my stock I need to try.

From the Tektronix replaceable parts reg. : 151-1124-00 = Siliconix J-2400...would'nt be surprised this was not a custom design but more likely tested/hand picked J300s jfets and assigned a Tektronix custom part# from Siliconix...searching Siliconix j-2400 brings up nothing...Id suspect most input boards from that 22xx series scopes came off the assembly line with "J300" marked Jfets in those Q122/222 positions..thanks




Re: Special Offer from Peter Keller to TekScopes Members: The Cathode Ray Tube, Technology, History, and Applications"

Tom Lee
 

Hi Barry,

Pete's book mainly covers electrostatically deflected crts. Except for some very early models, TVs used magnetically deflected crts (to allow large screens without absurd set depths). The guns are similar, but the deflection methods are very different because of the different optimization objectives.

--Tom

--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
http://www-smirc.stanford.edu

On 11/16/2020 07:18, n4buq wrote:
Does anyone know whether this book covers CRTs that were used for color TVs (and other color displays)? I ask because I'm not finding good information on how those work.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Dennis Tillman W7pF" <dennis@ridesoft.com>
To: TekScopes@groups.io
Sent: Monday, November 16, 2020 12:15:11 AM
Subject: Re: [TekScopes] Special Offer from Peter Keller to TekScopes Members: The Cathode Ray Tube, Technology,
History, and Applications"

Hi Chris,
I don't expect any problems shipping this to Germany.

One correction:
This offer is strictly between Peter Keller and individual members of the
group. I did offer to act as the go-between because I thought there might be
some interest and because I understood how "sensitive" our members are to
price. I was also hoping this would give Peter some well-deserved cash as we
get close to the holidays.

So I told Peter I thought I might be able to pass along 10 orders for his
book. When he said OK I notified TekScopes. That was 36 hours ago. I have
orders for over 50 of his books as of this moment.

This brings back memories of when I asked for small donations to pay
Groups.io the annual fee for hosting TekScopes back at the beginning of the
year. Somebody please remind me the next time I think up something like this
to think twice about what happened the last two times I had a bright idea.
:)

Dennis Tillman W7pF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of ChrisBeee
via groups.io
Sent: Sunday, November 15, 2020 8:47 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Special Offer from Peter Keller to TekScopes
Members: The Cathode Ray Tube, Technology, History, and Applications"

Hi Dennis,
I would be more than glad if I could support the group buy and get a copy of
Peter's book, many thanks for making this possible! My only concern is if
you would ship to Germany too. I will send you a PM with my contact data.
Cheers
Chris







--
Dennis Tillman W7pF
TekScopes Moderator







Tek 577 D1 storage adjustment questions.

Eric
 

I am working on some 577’s D1 storage curve tracers. I am trying to get a 178 working. So I need the storage tubes up and running. I do not have much experience with storage tubes hence the noob question. I think one of these units has been miss adjusted pretty badly, my problem Is I do not know which one. When I do the 6 minute startup as called for in the manual both units will get some glow bloom on the tubes. One is far dimmer then the other but both tubes have really good brightness so I do not believe that it is a tired tube. If I hit erase on both tubes they will blank as expected but the bright one will again go to full glow. At the full brightness the tube will not actually store anything as it looks like the glow is too bright. On the dimmer tube after the initial power up the tube will not bloom any more in storage mod and it will store a waveform however the “brightness control” must be all the way up. At minimum storage brightness it will store but it will only store at the edges.

So having minimal exposure to storage tubes is this normal behavior or is one or both miss adjusted? I can take some pictures if it will help. In the service manual it talks about adjusting the tubes but it does not say where the brightness control should be during the adjustment curious if anyone has insight on that as well.

Thanks,


Re: 577 D1 IV curve question

DW
 

Yes, I am reffering to the kink at the left side of the trace, the IV curve appears to be pushed up higher on the screen than normal


Re: 577 D1 IV curve question

DW
 

Thanks for the replies

Refer to this link below
https://groups.io/g/TekScopes/photo/255355/1?p=Created,,,20,2,0,0
The offset knob is set to 0 and the ZERO and AID switches are IN. I pushed them in and out and observed no change in behavior

https://groups.io/g/TekScopes/photo/255355/0?p=Created,,,20,2,0,0
With ZERO and AID switches set in the OUT position and the offset set to 4 I am able to remove the vertical offset of the IV curve where it appears to look normal.

This seems to be a new problem that has occurred recently, when I got this instrument I don't recall this problem from before.


Re: 577 D1 IV curve question

Michael W. Lynch
 

Dennis beat me to it. Are you possibly referring to that little kink near the left side of the trace?

--
Michael Lynch
Dardanelle, AR


Re: Special Offer from Peter Keller to TekScopes Members: The Cathode Ray Tube, Technology, History, and Applications"

Chuck Harris <cfharris@...>
 

It has about 100 pages on TV type CRT's.

CONTENTS

Cathode-Ray Tube Fundamentals
A Laboratory Curiosity
RADAR Indicator Cathode-Ray Tubes
Oscilloscope Cathode-Ray Tubes
Monochrome Television Picture Tubes
Color Television Picture Tubes
Data Display Cathode-Ray Tubes
Avionics and Vehicular Cathode-Ray Tubes
Photo-Recording Cathode-Ray Tubes
Flat Cathode-Ray Tubes...

There are about 300 pages in total

-Chuck Harris

n4buq wrote:

Does anyone know whether this book covers CRTs that were used for color TVs (and other color displays)? I ask because I'm not finding good information on how those work.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Dennis Tillman W7pF" <dennis@ridesoft.com>
To: TekScopes@groups.io
Sent: Monday, November 16, 2020 12:15:11 AM
Subject: Re: [TekScopes] Special Offer from Peter Keller to TekScopes Members: The Cathode Ray Tube, Technology,
History, and Applications"

Hi Chris,
I don't expect any problems shipping this to Germany.

One correction:
This offer is strictly between Peter Keller and individual members of the
group. I did offer to act as the go-between because I thought there might be
some interest and because I understood how "sensitive" our members are to
price. I was also hoping this would give Peter some well-deserved cash as we
get close to the holidays.

So I told Peter I thought I might be able to pass along 10 orders for his
book. When he said OK I notified TekScopes. That was 36 hours ago. I have
orders for over 50 of his books as of this moment.

This brings back memories of when I asked for small donations to pay
Groups.io the annual fee for hosting TekScopes back at the beginning of the
year. Somebody please remind me the next time I think up something like this
to think twice about what happened the last two times I had a bright idea.
:)

Dennis Tillman W7pF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of ChrisBeee
via groups.io
Sent: Sunday, November 15, 2020 8:47 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Special Offer from Peter Keller to TekScopes
Members: The Cathode Ray Tube, Technology, History, and Applications"

Hi Dennis,
I would be more than glad if I could support the group buy and get a copy of
Peter's book, many thanks for making this possible! My only concern is if
you would ship to Germany too. I will send you a PM with my contact data.
Cheers
Chris







--
Dennis Tillman W7pF
TekScopes Moderator










Re: 577 D1 IV curve question

 

Hi DW,
It would help if you said what you thought was odd about the curves so we knew what we were looking for.
There is nothing wrong at all as far as I can tell other than the base steps are offset. To confirm this turn the silver 10 turn OFFSET pot. As you turn it the offset will change making the entire set of curves move up and down on the CRT.
The odd thing is the offset button does not appear to be in the "activated" position. Try pressing this push button. It may be stuck somehow in the active position.
Dennis Tillman W7pF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of DW
Sent: Monday, November 16, 2020 7:26 AM
To: TekScopes@groups.io
Subject: [TekScopes] 577 D1 IV curve question

Hello, I have a 577 D1 serial B030223 that appears to have developed a slight problem with displaying an IV curve

https://groups.io/g/TekScopes/photo/255355/2?p=Created,,,20,2,0,0

If you click on the link above notice the oddly displayed IV curve, I also included pictures of the instrument settings if that is questioned

Any one experience this issue before or have any thoughts, thanks







--
Dennis Tillman W7pF
TekScopes Moderator


Re: Peter Keller CRT book

 

Hi Simon,
Yes, I got your info and added you to the list.
I will keep everyone posted via TekScopes on what comes next once the orders stop, Peter runs out of books, or I stop accepting orders in about 5 days.
Dennis

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Simon
Sent: Sunday, November 15, 2020 11:01 PM
To: TekScopes@groups.io
Subject: [TekScopes] Peter Keller CRT book

Hello Dennis

Did you get my request for a copy?

Simon Jarman
Tougnet
32100 Castelnau sur l'Auvignon
FRANCE

Best regards

Simon Jarman








--
Dennis Tillman W7pF
TekScopes Moderator


577 D1 IV curve question

DW
 

Hello, I have a 577 D1 serial B030223 that appears to have developed a slight problem with displaying an IV curve

https://groups.io/g/TekScopes/photo/255355/2?p=Created,,,20,2,0,0

If you click on the link above notice the oddly displayed IV curve, I also included pictures of the instrument settings if that is questioned

Any one experience this issue before or have any thoughts, thanks


Re: Special Offer from Peter Keller to TekScopes Members: The Cathode Ray Tube, Technology, History, and Applications"

n4buq
 

Does anyone know whether this book covers CRTs that were used for color TVs (and other color displays)? I ask because I'm not finding good information on how those work.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Dennis Tillman W7pF" <dennis@ridesoft.com>
To: TekScopes@groups.io
Sent: Monday, November 16, 2020 12:15:11 AM
Subject: Re: [TekScopes] Special Offer from Peter Keller to TekScopes Members: The Cathode Ray Tube, Technology,
History, and Applications"

Hi Chris,
I don't expect any problems shipping this to Germany.

One correction:
This offer is strictly between Peter Keller and individual members of the
group. I did offer to act as the go-between because I thought there might be
some interest and because I understood how "sensitive" our members are to
price. I was also hoping this would give Peter some well-deserved cash as we
get close to the holidays.

So I told Peter I thought I might be able to pass along 10 orders for his
book. When he said OK I notified TekScopes. That was 36 hours ago. I have
orders for over 50 of his books as of this moment.

This brings back memories of when I asked for small donations to pay
Groups.io the annual fee for hosting TekScopes back at the beginning of the
year. Somebody please remind me the next time I think up something like this
to think twice about what happened the last two times I had a bright idea.
:)

Dennis Tillman W7pF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of ChrisBeee
via groups.io
Sent: Sunday, November 15, 2020 8:47 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Special Offer from Peter Keller to TekScopes
Members: The Cathode Ray Tube, Technology, History, and Applications"

Hi Dennis,
I would be more than glad if I could support the group buy and get a copy of
Peter's book, many thanks for making this possible! My only concern is if
you would ship to Germany too. I will send you a PM with my contact data.
Cheers
Chris







--
Dennis Tillman W7pF
TekScopes Moderator






Re: Q122/222 Jfet J300 subs for 2215A scope ?

charlesterrebonne@...
 

thanks to all who replied - the 2215A scope is off the bench for now but Ill get back to it soon and will report when I get this working...I am almost at the point of sticking a high quality transistor socket there and just trying some other close to J300 specs Jfets I have on hand...FYI all the parts I have tried in the Q122/Q222 position in the scope : 2N3918, NTE133, k19, NTE132 tested good out of circuit...i have some more Jfet #s in my stock I need to try.

From the Tektronix replaceable parts reg. : 151-1124-00 = Siliconix J-2400...would'nt be surprised this was not a custom design but more likely tested/hand picked J300s jfets and assigned a Tektronix custom part# from Siliconix...searching Siliconix j-2400 brings up nothing...Id suspect most input boards from that 22xx series scopes came off the assembly line with "J300" marked Jfets in those Q122/222 positions..thanks

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