Date   

Re: CRT book by Keller

Roy Thistle
 

On Thu, Jan 14, 2021 at 12:20 PM, Tom Lee wrote:


If someone were to hand you a non-Coke bottle crt, would you ask, "Yeah, but what does it do?"
No... but if it was claimed to be an "operable" Coketron, I would. (... a topic which is apparently broached in subsequent posts.)


Re: CRT book by Keller

Tom Lee
 

Not a dumb question at all! These were (supposed to be) working crts, so they pulled a vacuum. In the picture in Pete's book, though, there's no visible close-off nipple. I also don't see a getter, so the cathode didn't have a long life. But I would still want one (lit up and showing a trace, of course).

--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 1/14/2021 19:01, n4buq wrote:
Maybe a dumb question, but did they pull a vacuum on the coke bottle?

Thanks,
Barry - N4BUQ

----- Original Message -----

From: "Tom Lee" <tomlee@ee.stanford.edu>
To: TekScopes@groups.io
Sent: Thursday, January 14, 2021 6:32:05 PM
Subject: Re: [TekScopes] CRT book by Keller
The Coketron actually has no components inside the Coke bottle. It takes what
I believe is a 1EP1, sans screen, and mates it to a Coke bottle. It actually
has deflection plates (at least, that’s what I recall from visiting
Vintagetek, where they have one on display), so it has all the guts of an
electrostatically deflected scope crt.
I never saw one light up, though.
—Cheers,
Tom
Sent from my iThing, so please forgive typos and brevity.
On Jan 14, 2021, at 3:47 PM, Jeff Dutky <jeff.dutky@gmail.com> wrote:

Chuck,

That's what I figured. The neck of a Coke bottle is pretty narrow to get
much of a mechanism through.

-- Jef Dutky






Re: CRT book by Keller

n4buq
 

Maybe a dumb question, but did they pull a vacuum on the coke bottle?

Thanks,
Barry - N4BUQ

----- Original Message -----

From: "Tom Lee" <tomlee@ee.stanford.edu>
To: TekScopes@groups.io
Sent: Thursday, January 14, 2021 6:32:05 PM
Subject: Re: [TekScopes] CRT book by Keller
The Coketron actually has no components inside the Coke bottle. It takes what
I believe is a 1EP1, sans screen, and mates it to a Coke bottle. It actually
has deflection plates (at least, that’s what I recall from visiting
Vintagetek, where they have one on display), so it has all the guts of an
electrostatically deflected scope crt.
I never saw one light up, though.
—Cheers,
Tom
Sent from my iThing, so please forgive typos and brevity.
On Jan 14, 2021, at 3:47 PM, Jeff Dutky <jeff.dutky@gmail.com> wrote:

Chuck,

That's what I figured. The neck of a Coke bottle is pretty narrow to get
much of a mechanism through.

-- Jef Dutky





Re: Who has not received their book in the US by now?

 

FastGuido:
The reason I requested people to reply OFF-LIST was to avoid unnecessary (and useless) replies to TekScopes that serve no purpose for every one of our 8,000+ members who received it wasting their bandwidth and storage, and requiring them to take time to delete.

Please use some common sense and stop replying to the list when someone says to specifically contact them OFF-LIST.

Dennis Tillman W7pF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of fastguido@charter.net
Sent: Thursday, January 14, 2021 4:37 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Who has not received their book in the US by now?

Also sent off a email.







--
Dennis Tillman W7pF
TekScopes Moderator


Re: T912 storage oscilloscope - No 2.7 KV high Voltage

Trevor
 

Attilio-

Please note that the two diodes should be "Fast Recovery" (100ns) since the frequency is 50 kHz or so.

Trevor


Re: Who has not received their book in the US by now?

fastguido@...
 

Also sent off a email.


Re: 2465B trace and readout focus at different positions of focus knob

Mark Hatch
 

Thanks! I remember several years ago replacing the u400 hybrid because I had a distorted video (see https://www.youtube.com/watch?v=KGj_ssJxkEA&t=42s ), but I suspect I never ran through the calibration procedures fully after that.

Regards,

Mark


Re: CRT book by Keller

Tom Lee
 

The Coketron actually has no components inside the Coke bottle. It takes what I believe is a 1EP1, sans screen, and mates it to a Coke bottle. It actually has deflection plates (at least, that’s what I recall from visiting Vintagetek, where they have one on display), so it has all the guts of an electrostatically deflected scope crt.

I never saw one light up, though.

—Cheers,
Tom

Sent from my iThing, so please forgive typos and brevity.

On Jan 14, 2021, at 3:47 PM, Jeff Dutky <jeff.dutky@gmail.com> wrote:

Chuck,

That's what I figured. The neck of a Coke bottle is pretty narrow to get much of a mechanism through.

-- Jef Dutky





Re: CRT book by Keller

 

Chuck,

That's what I figured. The neck of a Coke bottle is pretty narrow to get much of a mechanism through.

-- Jef Dutky


Re: Who has not received their book in the US by now?

Stephen
 

E-mail sent offline.


Re: CRT book by Keller

Chuck Harris <cfharris@...>
 

Originally, the cathode ray tube, was a device to project
"cathode rays" at a phosphor screen... possibly with some
object (Maltese Cross) in between.

As I understand the description of the Coketron, it has something
like one of the ubiquitous 5UP1 gun assemblies in the neck, and
no internal deflection plates.

So, you should be able to focus the beam, and with a magnet do
experiments with magnetic deflection of said beam.

-Chuck Harris

Jeff Dutky wrote:

Tom,

I actually have the same question as Roy.

There are "CRTs" that merely illuminate the entire face of the tube, and others that have some limited amount of control over the illumination (e.g. the 6E5 tuning eye, or DM160 "Magic-Eye" indicator tubes). It is not clear from the description that the "coketron" was able to scan the beam, or whether it merely caused the end of the tube to illuminate like these Russian ILD3-K tubes (https://www.ebay.com/itm/ILD3-K-P590-ULTRARARE-VINTAGE-CRT-VFD-INDICATOR-TUBE-for-DIY-and-education/112031678404).

My copy of Peter Keller's book has not arrived, so I am speaking from a certain depth of ignorance.

-- Jeff Dutky






Re: Tektronix 492BP

 

I think option 8 remove the extended frequency. This unit may had that as the options tag has been erased as it is old probably 90s.


Re: 2465B trace and readout focus at different positions of focus knob

Chuck Harris <cfharris@...>
 

Yes, that is where the compromise that makes both
focus at about the same point happens.

Unfortunately, it is a compromise adjustment. The
readout is considered the designated loser in this
race.

-Chuck Harris

Mark Hatch wrote:

Hi,

Have a late model 2465B. Noticed today that the focus point for the readout is at one point on the focus knob. But it I also want to get an optimal focus for the trace, I need to turn the knob to a different position.

I guessing that I should first perform the 2465B CRT Adjustments (Grid Bias, High Drive Focus, and Edge Focus). Is this the right path here?

Focus knob is more or less in the center position when Readout is in focus and only a little off center with trace in focus.

Thanks

Mark






Re: Tektronix 492BP

 

May have been unit has been opened before, but works fine up to 21GHz. But what switches do you refer to on what board? Where can I find where the switches suppose to be?


Who has not received their book in the US by now?

 

If you have NOT received Peter Keller's book by now please contact me
off-list at dennis at ridesoft dot com and I will see if I can locate it for
you. Include your zip code in your email.

If you DID NOT receive Peter's book in the mail by TUESDAY EVENING please
let me know and include your zip code in the email.

Dennis Tillman W7pF


Re: CRT book by Keller

 

Tom,

I actually have the same question as Roy.

There are "CRTs" that merely illuminate the entire face of the tube, and others that have some limited amount of control over the illumination (e.g. the 6E5 tuning eye, or DM160 "Magic-Eye" indicator tubes). It is not clear from the description that the "coketron" was able to scan the beam, or whether it merely caused the end of the tube to illuminate like these Russian ILD3-K tubes (https://www.ebay.com/itm/ILD3-K-P590-ULTRARARE-VINTAGE-CRT-VFD-INDICATOR-TUBE-for-DIY-and-education/112031678404).

My copy of Peter Keller's book has not arrived, so I am speaking from a certain depth of ignorance.

-- Jeff Dutky


Re: Tektronix 492BP

Thomas S. Knutsen
 

You want to check those dip switches again, the alternative may be that the
EPROM is losing its memory, and that's not a fault you want to have.
Could it be that the switches have been fooled with by a former owner?

BR.
Thomas.


tor. 14. jan. 2021 kl. 21:56 skrev Mike Yepes <theamberco@hotmail.com>:

Thanks a lot for hte help but the dip switches on those boards are ok.
(Vertical digital storage and memory board)





--
With Best regards, Thomas S. Knutsen.

Please avoid sending me Word or PowerPoint attachments.


Re: Tektronix 492BP

 

Thanks a lot for hte help but the dip switches on those boards are ok. (Vertical digital storage and memory board)


Re: CRT book by Keller

Tom Lee
 

Your question baffles me, Roy. If someone were to hand you a non-Coke bottle crt, would you ask, "Yeah, but what does it do?"

It's a crt. Made out of a Coke bottle, yes, but a crt nonetheless.

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 1/14/2021 12:09, Roy Thistle wrote:
On Wed, Jan 13, 2021 at 05:49 PM, Glydeck wrote:

check it out
There is a bad photo of Peter's artifact... and as Peter claims... '... results in an operable CRT..." [pg. 24]
But given that it was "operable," what did it do?
Peter doesn't say?




Re: CRT book by Keller

Roy Thistle
 

On Wed, Jan 13, 2021 at 05:49 PM, Glydeck wrote:


check it out
There is a bad photo of Peter's artifact... and as Peter claims... '... results in an operable CRT..." [pg. 24]
But given that it was "operable," what did it do?
Peter doesn't say?

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