low profile CRTs?

Guest
I was wondering if anyone knows of any CRT's that are very
low-profile? I know that quite a bit of space is required for the
emittor, but are there any '90 degree' CRT's out there that maybe use
a mirror to reflect the emissions onto the display or something like
that?
Basically, im trying to build an oscilloscope into the body of an
electric bass guitar, so you can see every note thats being played.
I have to fit a mini CRT into an area about 2 inches deep, and the
smallest CRTs ive found (with any sort of decent, usable screen size),
are at least 2.5, 3 inches long/deep. I had thought of mounting one
sideways, and reflecting the display onto a sort of internal
projection plate, but then I'd have to focus it with a lens probably,
and it still wouldn't quite look right

I dont want to use LCD, because most of the LCD scopes i see have
black lines, instead of the cool glowing green dot/lines like a CRT.

Any Ideas?
-Doc
 
Oscilloscope tubes are generally made very long, in order to have very low
scan distortions. In TV CRT's Sony used to make a model of watchman about
18+ years ago. The set and all parts are out of production. This CRT had
the neck bent at very steep angle from the tube. I think it was at 90%, if I
remember right. For the Horiz deflection, they used a winding as used on a
deflection yoke. For the vertical deflection, I think it used deflection
plates, just like a scope tube.

If you want to use a CRT and make a scope device, this is an unusual home
project. There is a lot involved, especially in designing and building an
inverter to get the necessary high voltage to run the tube, and designing
the precision scan amplifiers, blanking, and Z drive that are required.

--

Greetings,

Jerry Greenberg GLG Technologies GLG
=========================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
=========================================


<datamancer0@hotmail.com> wrote in message
news:s77f601d368eh3a3vl756lod9kfr4upvln@4ax.com...
I was wondering if anyone knows of any CRT's that are very
low-profile? I know that quite a bit of space is required for the
emittor, but are there any '90 degree' CRT's out there that maybe use
a mirror to reflect the emissions onto the display or something like
that?
Basically, im trying to build an oscilloscope into the body of an
electric bass guitar, so you can see every note thats being played.
I have to fit a mini CRT into an area about 2 inches deep, and the
smallest CRTs ive found (with any sort of decent, usable screen size),
are at least 2.5, 3 inches long/deep. I had thought of mounting one
sideways, and reflecting the display onto a sort of internal
projection plate, but then I'd have to focus it with a lens probably,
and it still wouldn't quite look right

I dont want to use LCD, because most of the LCD scopes i see have
black lines, instead of the cool glowing green dot/lines like a CRT.

Any Ideas?
-Doc
 
<datamancer0@hotmail.com> wrote in message
news:s77f601d368eh3a3vl756lod9kfr4upvln@4ax.com...
I was wondering if anyone knows of any CRT's that are very
low-profile? I know that quite a bit of space is required for the
emittor, but are there any '90 degree' CRT's out there that maybe use
a mirror to reflect the emissions onto the display or something like
that?
Basically, im trying to build an oscilloscope into the body of an
electric bass guitar, so you can see every note thats being played.
I have to fit a mini CRT into an area about 2 inches deep, and the
smallest CRTs ive found (with any sort of decent, usable screen size),
are at least 2.5, 3 inches long/deep. I had thought of mounting one
sideways, and reflecting the display onto a sort of internal
projection plate, but then I'd have to focus it with a lens probably,
and it still wouldn't quite look right

I dont want to use LCD, because most of the LCD scopes i see have
black lines, instead of the cool glowing green dot/lines like a CRT.

Any Ideas?
-Doc
Click to expand...
It's an interesting project and I hope that when you have completed it you
will give us a link to some pictures of the guitar. I don't know of any
CRTs that will fit the bill, especially once you take the mounting into
consideration - i would want to see a considerable amount of shock
protection in the mount for this.

What might prove easier is to use an LCD display but generate your own
signal. Something like a PIC microcontroller with an A-D input that would
generate a video based signal can drive an LCD of any size. I believe this
will work well beause you will be able to select any display colour you
like, you can select any background you like and as this is for display
rather than scientific work, it doesn't matter if the calibration isn't
accurate. There is a fair bit of work involved in this, but if you are
contemplating building a CRT based display, you are obviously prepared to
put in a considerable effort to it. With a google search, you will probably
be able to find PIC based ocilliscope circuits or complete units.

Whichever solution you choose, be prepared to install a power supply that
will give you about 10 - 15W output to drive the electronics and the
display. If this is to be battery powered, you are talking about (for
example) 10 C size rechargables (12V) for up to 2 hours use.

Good luck
 
You could use a black/green LCD module (there are some out there...), or
a fluorescent module. You'll get somewhat "jaggy" lines, the way they
are on such displays, but that's still closer to what you want than
black lines on whitish background.

I really don't think you'll get anywhere with the idea of using a CRT,
even if it was very low profile.
Do you realize what it means in terms of power consumption, weight,
complexity of the HT driving circuit, etc.?

A PIC microcontroller with a green- or blue-on-black LCD would do the
job decently. Use some PIC with A/D inputs, that'd be far from enough
to display the input waveform.

Just my 2 cents.
 
datamancer0@hotmail.com wrote in message news:<s77f601d368eh3a3vl756lod9kfr4upvln@4ax.com>...
I was wondering if anyone knows of any CRT's that are very
low-profile? I know that quite a bit of space is required for the
emittor, but are there any '90 degree' CRT's out there that maybe use
a mirror to reflect the emissions onto the display or something like
that?
Basically, im trying to build an oscilloscope into the body of an
electric bass guitar, so you can see every note thats being played.
I have to fit a mini CRT into an area about 2 inches deep, and the
smallest CRTs ive found (with any sort of decent, usable screen size),
are at least 2.5, 3 inches long/deep. I had thought of mounting one
sideways, and reflecting the display onto a sort of internal
projection plate, but then I'd have to focus it with a lens probably,
and it still wouldn't quite look right
Click to expand...
Heh :) I've got one of those CRT's and driver boards here.

Its fairly thin, I'd guess about 1". Cost me about Ł30.

-A

I dont want to use LCD, because most of the LCD scopes i see have
black lines, instead of the cool glowing green dot/lines like a CRT.

Any Ideas?
-Doc
Click to expand...
 
This company http://custom1.farnell.com/cpc/ can supply a module with a 5
inch sideways scanning CRT with a video drive input. Only black and white
though designed for a video test monitor badged Sony inside.
 
"John" <Johnferrier@irish4ever.com> wrote in message news:<HA0ac.37$24.0@newsfe3-win.server.ntli.net>...
This company http://custom1.farnell.com/cpc/ can supply a module with a 5
inch sideways scanning CRT with a video drive input. Only black and white
though designed for a video test monitor badged Sony inside.
Click to expand...
That's basically what I have :)

-A
 
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