Curved CRTs?


 

Hi guys,
I wonder why no one ever made CRTs that curve around? Long CRTs are very
thin cones and I wonder if anyone tried "folding" them into a spiral. If
the glasswork were precise enough, the electrons could be led through the
spiral without need for a very long CRT.


David Slipper
 

Not sure how practical that is.

However, CRTs that had the gun to one side were made - the beam being
bent at right angles, I think, I seem to remember that some guy used
them in a portable TV.

Dave

On 28/12/2017 22:10, cheater cheater wrote:
Hi guys,
I wonder why no one ever made CRTs that curve around? Long CRTs are very
thin cones and I wonder if anyone tried "folding" them into a spiral. If
the glasswork were precise enough, the electrons could be led through the
spiral without need for a very long CRT.



.


stefan_trethan
 

As far as I know those miniature Panasonic TVs had a straight beam.
The screen was tilted at a severe angle to make it sort of flat, and
you watched the electron side through a window in the side of the
tube..

Might be there were others that I don't know of.

Somewhere I have an old camera with a tiny CRT in the viewfinder, but
I think it is straight.
I should really make that operational again, as a display piece, in a
clear box.
It even took regular composite video in, should be able to drive that
with a raspberry pi or something.

ST

On Thu, Dec 28, 2017 at 11:37 PM, David Slipper <softfoot@hotmail.com> wrote:

Not sure how practical that is.

However, CRTs that had the gun to one side were made - the beam being
bent at right angles, I think, I seem to remember that some guy used
them in a portable TV.

Dave



On 28/12/2017 22:10, cheater cheater wrote:
Hi guys,
I wonder why no one ever made CRTs that curve around? Long CRTs are very
thin cones and I wonder if anyone tried "folding" them into a spiral. If
the glasswork were precise enough, the electrons could be led through the
spiral without need for a very long CRT.



.



Fabio Trevisan
 

Hi Guys,
Sony indeed made the equivalent of the Walkman as a TV... don't remember
how it was called, let's call it the "TV Man" (as the CD was DiscMan).
But on that mini TV, the beam was projected straight, the only thing is
that the phosphor screen was inclined so that it was viewed from its side,
instead of from its back... and the C.R.T. looking towards the gun, was a
thin rectangle.
Door Security Camera Monitors used this kind of CRT, for many years after
the Sony "TV Man" disappeared (not too long ago I still saw one of those
Door Camera Monitors).

Cheers and Happy 2018 to all.

Fabio

2017-12-28 20:37 GMT-02:00 David Slipper <softfoot@hotmail.com>:


Not sure how practical that is.

However, CRTs that had the gun to one side were made - the beam being
bent at right angles, I think, I seem to remember that some guy used
them in a portable TV.

Dave



On 28/12/2017 22:10, cheater cheater wrote:
Hi guys,
I wonder why no one ever made CRTs that curve around? Long CRTs are very
thin cones and I wonder if anyone tried "folding" them into a spiral. If
the glasswork were precise enough, the electrons could be led through the
spiral without need for a very long CRT.



.




EricJ
 

That would be the "Watchman."

https://en.m.wikipedia.org/wiki/Sony_Watchman

--Eric
Sent from my Samsung Galaxy S8.

-------- Original message --------From: Fabio Trevisan <fabio.tr3visan@gmail.com> Date: 12/28/17 4:58 PM (GMT-06:00) To: TekScopes@groups.io Subject: Re: [TekScopes] Curved CRTs?
Hi Guys,
Sony indeed made the equivalent of the Walkman as a TV... don't remember
how it was called, let's call it the "TV Man" (as the CD was DiscMan).
But on that mini TV, the beam was projected straight, the only thing is
that the phosphor screen was inclined so that it was viewed from its side,
instead of from its back... and the C.R.T. looking towards the gun, was a
thin rectangle.
Door Security Camera Monitors used this kind of CRT, for many years after
the Sony "TV Man" disappeared (not too long ago I still saw one of those
Door Camera Monitors).

Cheers and Happy 2018 to all.

Fabio

2017-12-28 20:37 GMT-02:00 David Slipper <softfoot@hotmail.com>:


Not sure how practical that is.

However, CRTs that had the gun to one side were made - the beam being
bent at right angles, I think, I seem to remember that some guy used
them in a portable TV.

Dave



On 28/12/2017 22:10, cheater cheater wrote:
Hi guys,
I wonder why no one ever made CRTs that curve around? Long CRTs are very
thin cones and I wonder if anyone tried "folding" them into a spiral. If
the glasswork were precise enough, the electrons could be led through the
spiral without need for a very long CRT.



.




Brad Thompson <brad.thompson@...>
 

On 12/28/2017 5:37 PM, David Slipper wrote:
Not sure how practical that is.
However, CRTs that had the gun to one side were made - the beam being
bent at right angles, I think, I seem to remember that some guy used
them in a portable TV.
Hello, Dave and the group--

Possibly in the Sony Watchman small TV?

73--

Brad AA1IP


cnc_joker <preilley_454@...>
 

Not "TV man" but "Watchman".

https://en.wikipedia.org/wiki/Sony_Watchman

Pete.

On 12/28/2017 5:58 PM, Fabio Trevisan wrote:
Hi Guys,
Sony indeed made the equivalent of the Walkman as a TV... don't remember
how it was called, let's call it the "TV Man" (as the CD was DiscMan).
But on that mini TV, the beam was projected straight, the only thing is
that the phosphor screen was inclined so that it was viewed from its side,
instead of from its back... and the C.R.T. looking towards the gun, was a
thin rectangle.
Door Security Camera Monitors used this kind of CRT, for many years after
the Sony "TV Man" disappeared (not too long ago I still saw one of those
Door Camera Monitors).

Cheers and Happy 2018 to all.

Fabio

2017-12-28 20:37 GMT-02:00 David Slipper <softfoot@hotmail.com>:

Not sure how practical that is.

However, CRTs that had the gun to one side were made - the beam being
bent at right angles, I think, I seem to remember that some guy used
them in a portable TV.

Dave



On 28/12/2017 22:10, cheater cheater wrote:
Hi guys,
I wonder why no one ever made CRTs that curve around? Long CRTs are very
thin cones and I wonder if anyone tried "folding" them into a spiral. If
the glasswork were precise enough, the electrons could be led through the
spiral without need for a very long CRT.



.



Fabio Trevisan
 

Guys...

2017-12-28 21:03 GMT-02:00 EricJ via Groups.Io <
wyzkydd2358=yahoo.com@groups.io>:
That would be the "Watchman."
Bingo! I don't know I couldn't recall the name!

Rgrds,

Fabio

2017-12-28 21:03 GMT-02:00 EricJ via Groups.Io <
wyzkydd2358=yahoo.com@groups.io>:

That would be the "Watchman."

https://en.m.wikipedia.org/wiki/Sony_Watchman

--Eric
Sent from my Samsung Galaxy S8.
-------- Original message --------From: Fabio Trevisan <
fabio.tr3visan@gmail.com> Date: 12/28/17 4:58 PM (GMT-06:00) To:
TekScopes@groups.io Subject: Re: [TekScopes] Curved CRTs?
Hi Guys,
Sony indeed made the equivalent of the Walkman as a TV... don't remember
how it was called, let's call it the "TV Man" (as the CD was DiscMan).
But on that mini TV, the beam was projected straight, the only thing is
that the phosphor screen was inclined so that it was viewed from its side,
instead of from its back... and the C.R.T. looking towards the gun, was a
thin rectangle.
Door Security Camera Monitors used this kind of CRT, for many years after
the Sony "TV Man" disappeared (not too long ago I still saw one of those
Door Camera Monitors).

Cheers and Happy 2018 to all.

Fabio

2017-12-28 20:37 GMT-02:00 David Slipper <softfoot@hotmail.com>:


Not sure how practical that is.

However, CRTs that had the gun to one side were made - the beam being
bent at right angles, I think, I seem to remember that some guy used
them in a portable TV.

Dave



On 28/12/2017 22:10, cheater cheater wrote:
Hi guys,
I wonder why no one ever made CRTs that curve around? Long CRTs are
very
thin cones and I wonder if anyone tried "folding" them into a spiral.
If
the glasswork were precise enough, the electrons could be led through
the
spiral without need for a very long CRT.



.









george edmonds
 

Hi all

On this side of the pond it was called a TV80 and sold by Clive Sinclair. A commercial disaster that cost £4 million to develop for very low sales volumes.

73 George G6HIG


Harvey White
 

On Thu, 28 Dec 2017 22:37:14 +0000, you wrote:


Not sure how practical that is.

However, CRTs that had the gun to one side were made - the beam being
bent at right angles, I think, I seem to remember that some guy used
them in a portable TV.
Sony, in their portable TVs that looked a bit like the old Star Trek
Tricorder.

Angled, but maybe at 60 degrees? B&W.

Harvey


Dave



On 28/12/2017 22:10, cheater cheater wrote:
Hi guys,
I wonder why no one ever made CRTs that curve around? Long CRTs are very
thin cones and I wonder if anyone tried "folding" them into a spiral. If
the glasswork were precise enough, the electrons could be led through the
spiral without need for a very long CRT.



.


Leon Robinson
 

It was called the Watchman. Leon Robinson    K5JLR

Political Correctness is a Political Disease.

From: Fabio Trevisan <fabio.tr3visan@gmail.com>
To: TekScopes@groups.io
Sent: Thursday, December 28, 2017 4:58 PM
Subject: Re: [TekScopes] Curved CRTs?

Hi Guys,
Sony indeed made the equivalent of the Walkman as a TV... don't remember
how it was called, let's call it the "TV Man" (as the CD was DiscMan).
But on that mini TV, the beam was projected straight, the only thing is
that the phosphor screen was inclined so that it was viewed from its side,
instead of from its back... and the C.R.T. looking towards the gun, was a
thin rectangle.
Door Security Camera Monitors used this kind of CRT, for many years after
the Sony "TV Man" disappeared (not too long ago I still saw one of those
Door Camera Monitors).

Cheers and Happy 2018 to all.

Fabio

2017-12-28 20:37 GMT-02:00 David Slipper <softfoot@hotmail.com>:


Not sure how practical that is.

However, CRTs that had the gun to one side were made - the beam being
bent at right angles, I think, I seem to remember that some guy used
them in a portable TV.

Dave



On 28/12/2017 22:10, cheater cheater wrote:
Hi guys,
I wonder why no one ever made CRTs that curve around? Long CRTs are very
thin cones and I wonder if anyone tried "folding" them into a spiral. If
the glasswork were precise enough, the electrons could be led through the
spiral without need for a very long CRT.



.




Kevin Oconnor
 

Do you really mean radically curving beam path? If I remember my grad physics correctly, that produces significant photon radiation losses via
Bremsstrahlung/synchrotron radiation. At 40-60kv that should make some nice x-rays all along the path.

Sent from kjo iPhone


Chuck Harris <cfharris@...>
 

If you put an electron gun at the center of a spiral
shaped glass tube, and launched an electron into the
glass tube, the electron would coast along in a straight
line, until it struck the wall of the tube, and was
dissipated. It would never see any electrode that you
put at the far end of the spiral tube... the tube is
full of vacuum, not ionized gas.

Through some means (magnetic or electrostatic) you would
need to accelerate and deflect the electron beam into
the same spiral path as the glass spiral shaped tube.

Sooner or later you would end up with something that
looked an awful lot like a cyclotron, or synchrotron.


-Chuck Harris

cheater cheater wrote:

Hi guys,
I wonder why no one ever made CRTs that curve around? Long CRTs are very
thin cones and I wonder if anyone tried "folding" them into a spiral. If
the glasswork were precise enough, the electrons could be led through the
spiral without need for a very long CRT.


Dave Seiter
 

Sinclair; didn't he also do the tiny Timex/Sinclair computer? I've got a TS1000 and accessories around somewhere.  I think it was called a Z8 or similar on the other side of the pond.
A folded CRT is really impractical, but if it worked, it would have made early high speed scopes more portable (I'm thinking of the Russian scopes with the really long CRTs).
-Dave

From: george edmonds <g_einst@hotmail.com>
To: TekScopes@groups.io
Sent: Thursday, December 28, 2017 3:53 PM
Subject: Re: [TekScopes] Curved CRTs?

Hi all

On this side of the pond it was called a TV80 and sold by Clive Sinclair.  A commercial disaster that cost £4 million to develop for very low sales volumes.

73 George G6HIG


ken chalfant
 

It was the SONY “Pocket Watchman”. I actually won one.

The CRT was very small and shaped rather like a square lollypop. The phosphor was on the curved back of the tube and the image was viewed through the flat, clear opposing “face” of the glass envelope.

It was a B&W TV that ran on a few batteries. I don’t remember much else. However, being very interested in oscilloscopes any unusual CRT caught my interest.

Searching the internet for “SONY pocket watchman” will bring up a few articles and some images.

Regards,

Ken

On 28Dec, 2017, at 5:50 PM, Leon Robinson <leon-robinson@sbcglobal.net> wrote:

It was called the Watchman. Leon Robinson K5JLR

Political Correctness is a Political Disease.

From: Fabio Trevisan <fabio.tr3visan@gmail.com>
To: TekScopes@groups.io
Sent: Thursday, December 28, 2017 4:58 PM
Subject: Re: [TekScopes] Curved CRTs?

Hi Guys,
Sony indeed made the equivalent of the Walkman as a TV... don't remember
how it was called, let's call it the "TV Man" (as the CD was DiscMan).
But on that mini TV, the beam was projected straight, the only thing is
that the phosphor screen was inclined so that it was viewed from its side,
instead of from its back... and the C.R.T. looking towards the gun, was a
thin rectangle.
Door Security Camera Monitors used this kind of CRT, for many years after
the Sony "TV Man" disappeared (not too long ago I still saw one of those
Door Camera Monitors).

Cheers and Happy 2018 to all.

Fabio

2017-12-28 20:37 GMT-02:00 David Slipper <softfoot@hotmail.com>:


Not sure how practical that is.

However, CRTs that had the gun to one side were made - the beam being
bent at right angles, I think, I seem to remember that some guy used
them in a portable TV.

Dave



On 28/12/2017 22:10, cheater cheater wrote:
Hi guys,
I wonder why no one ever made CRTs that curve around? Long CRTs are very
thin cones and I wonder if anyone tried "folding" them into a spiral. If
the glasswork were precise enough, the electrons could be led through the
spiral without need for a very long CRT.



.










ykochcal
 

On the other end of the extreme I recall reading about the US-Russian
nuclear reduction exchange, and the US showing the Russian inspectors the
"fast" US scopes and them being somewhat unimpressed because it turns out
the US scopes had to fit in a rack mount which limited there size and thus
length, deflection and speeds, The Russians used long 6 foot (might have
been 2 meter) CRTs tubes and a dark box to put you head in to get multi GHZ
scopes.

Can't seem to find any links

John

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of ken
chalfant
Sent: Thursday, December 28, 2017 10:04 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Curved CRTs?

It was the SONY "Pocket Watchman". I actually won one.

The CRT was very small and shaped rather like a square lollypop. The
phosphor was on the curved back of the tube and the image was viewed through
the flat, clear opposing "face" of the glass envelope.

It was a B&W TV that ran on a few batteries. I don't remember much else.
However, being very interested in oscilloscopes any unusual CRT caught my
interest.

Searching the internet for "SONY pocket watchman" will bring up a few
articles and some images.

Regards,

Ken


cmjones01
 

On Fri, Dec 29, 2017 at 5:51 AM, Dave Seiter <d.seiter@att.net> wrote:
Sinclair; didn't he also do the tiny Timex/Sinclair computer? I've got a TS1000
and accessories around somewhere. I think it was called a Z8 or similar on the
other side of the pond.
Yes, Sir Clive Sinclair did a lot of things, with varying degrees of
success. He was, and to some extent still is, a huge figure in the UK
technology scene. To position him in US culture, I'd make him a hybrid
of Earl Muntz and Steve Jobs. He started in the 1960s selling radio
and 'hi-fi' kits, often with outrageous claims as to their performance
which, let's say, customers found hard to replicate in real-world
conditions. Through the 1970s he made various innovations in digital
watches and pocket calculators, including an amazing scientific
calculator based on a TI chip which TI themselves said couldn't be
done. The real breakthroughs came in the early 1980s, with first the
ZX80 and then the ZX81 home computers. The ZX81 sold for £69.95 (less
than $100 at today's exchange rate) fully assembled, and it worked,
mostly, and came with an excellent instruction manual. It was so cheap
that almost anyone could afford one, and something like 1.5 million
people did - not bad for a nation of only 50 million or so people. It
was really a revolution: a computer for the man in the street. They
were everywhere, in homes, schools, laboratories, you name it.

I was 9 years old at the time and the ZX81 was the machine on which I
cut my computing teeth. I remember the day we got it, and I've still
got it here with me now. Other computers came afterwards (Sinclair's
own ZX Spectrum, and competitors from Acorn, Dragon, Commodore, Tandy
and the usual suspects), but my generation of British computing and
electronics enthusiasts and professionals owe Sir Clive
(affectionately known as 'uncle') a great debt. I'd like to shake his
hand.

Chris


Michael A. Terrell
 

I bought a Timex ZX81 for $20, when they were discontinued. The store had a couple pallets of those small computers to dispose of. I quickly found out why. They were touchy as hell when it came to storing or loading a program to a cassette tape. Mine came from the now defunct Swallen's stores, in Ohio.

-----Original Message-----
From: Dave Seiter <d.seiter@att.net>
Sent: Dec 28, 2017 11:51 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Curved CRTs?

Sinclair; didn't he also do the tiny Timex/Sinclair computer? I've got a TS1000 and accessories around somewhere.  I think it was called a Z8 or similar on the other side of the pond.
A folded CRT is really impractical, but if it worked, it would have made early high speed scopes more portable (I'm thinking of the Russian scopes with the really long CRTs).
-Dave

From: george edmonds <g_einst@hotmail.com>
To: TekScopes@groups.io
Sent: Thursday, December 28, 2017 3:53 PM
Subject: Re: [TekScopes] Curved CRTs?

Hi all

On this side of the pond it was called a TV80 and sold by Clive Sinclair.  A commercial disaster that cost £4 million to develop for very low sales volumes.

73 George G6HIG







Michael A. Terrell


Michael A. Terrell
 

http://englishrussia.com/ has some Russian built oscilloscopes, but you have to dig for them. Some are clones of tube type Tektronix scopes.

WARNING! The site is a huge time sink, so don't blame me if you spend hours or days looking at the 1000+ pages.

-----Original Message-----
From: ykochcal <Kochcal@earthlink.net>
Sent: Dec 29, 2017 4:16 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Curved CRTs?

On the other end of the extreme I recall reading about the US-Russian
nuclear reduction exchange, and the US showing the Russian inspectors the
"fast" US scopes and them being somewhat unimpressed because it turns out
the US scopes had to fit in a rack mount which limited there size and thus
length, deflection and speeds, The Russians used long 6 foot (might have
been 2 meter) CRTs tubes and a dark box to put you head in to get multi GHZ
scopes.

Can't seem to find any links

John



-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of ken
chalfant
Sent: Thursday, December 28, 2017 10:04 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Curved CRTs?

It was the SONY "Pocket Watchman". I actually won one.

The CRT was very small and shaped rather like a square lollypop. The
phosphor was on the curved back of the tube and the image was viewed through
the flat, clear opposing "face" of the glass envelope.

It was a B&W TV that ran on a few batteries. I don't remember much else.
However, being very interested in oscilloscopes any unusual CRT caught my
interest.

Searching the internet for "SONY pocket watchman" will bring up a few
articles and some images.

Regards,

Ken




Michael A. Terrell


 

Hi Cheater,

As Chuck Harris and Kevin O'Connor pointed out the closest you can come (in common practice) is coaxing electrons to move in a circle in a cyclotron or synchrotron.

Electrons move in a straight line unless they are deflected by an electric field or a magnetic field or both. It is possible to precisely balance an electric field and a magnetic field to get an electron to move in a circle. This is done in a cyclotron or synchrotron. It is even possible to keep these forces balanced while the electron speeds up to within a few percent of the speed of light.

It would be a good use of your time to read up on how a cyclotron or synchrotron works. That would lay the groundwork for adding a third dimension to the electron's path to turn the circle into a helix. This wonderful Wikipedia article is not too hard to understand and it has lots of pictures:

https://en.wikipedia.org/wiki/Particle_accelerator

Once you understand what deflects, attracts, and repels electrons in a cyclotron's circular path you can try to sketch out the geometry of a pair (or more!!) of deflection plates that would be needed to coax a continuous stream of electrons to SIMULTANEOUSLY stay focused as it travels in a helix at ever increasing speed (which will eventually reach 3% to 5% of the speed of light) while being accelerated towards the front of the CRT. Don't forget to include vertical (amplitude) and horizontal (time base) deflection into your sketch of the deflection plates that would make an electron beam do all those cool things. I have no idea how to figure the geometry of deflection plates for a helical CRT that can do all that.

If I remember correctly the neck of most TV picture tubes, computer monitors, and Tektronix CRTs I have seen are at least an inch or more in diameter so wouldn't the helical tube you are thinking of also have a fat neck?

Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Chuck Harris
Sent: Thursday, December 28, 2017 7:34 PM
Subject: Re: [TekScopes] Curved CRTs?

If you put an electron gun at the center of a spiral shaped glass tube, and launched an electron into the glass tube, the electron would coast along in a straight line, until it struck the wall of the tube, and was dissipated. It would never see any electrode that you put at the far end of the spiral tube... the tube is full of vacuum, not ionized gas.

Through some means (magnetic or electrostatic) you would need to accelerate and deflect the electron beam into the same spiral path as the glass spiral shaped tube.

Sooner or later you would end up with something that looked an awful lot like a cyclotron, or synchrotron.


-Chuck Harris

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Kevin Oconnor
Sent: Thursday, December 28, 2017 6:39 PM
Subject: Re: [TekScopes] Curved CRTs?

Do you really mean radically curving beam path? If I remember my grad physics correctly, that produces significant photon radiation losses via Bremsstrahlung/synchrotron radiation. At 40-60kv that should make some nice x-rays all along the path.

Sent from kjo iPhone
cheater cheater wrote:
Hi guys,
I wonder why no one ever made CRTs that curve around? Long CRTs are
very thin cones and I wonder if anyone tried "folding" them into a
spiral. If the glasswork were precise enough, the electrons could be
led through the spiral without need for a very long CRT.




--
Dennis Tillman W7PF
TekScopes Moderator