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Replacement for CRT?
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440roadrunner:

--- Quote from: N2IXK on February 14, 2014, 08:03:45 pm ---I think this is more akin to an oscilloscope CRT, so there isn't a real "video format" to convert from. Just X and Y deflection voltages, and intensity modulation on the Z axis. Every service monitor I have seen used an electrostatic deflection tube, not a magnetic deflection, raster scanned type.

The flat panel LCD conversions are easier to do in raster scan applications like CNC controllers, or Dave's HP signal analyzer a while back.

--- End quote ---

This is correct.  The  CRT and amplifiers   use  conventional  analong  o'scope  "thinking"    IE  Z azis  and   XY  plates.    Because  I'm not up on  modern   O'scope  technology and displays,  I'm not sure   what  I can do.    The reason  I need  Z  is because this thing  displays  a  lot  of functions  in  graphics  and  menus  and so on     I  don't think  there  is what you might  call  "composit video"  anywhere in the device.    I  don't know enough about video systems  to  figure out how to  work around it





 
woodchips:
What are the dimensions of the CRT? What are the X, Y and Z bandwidths? What sort of deflection voltages are used?

The alphanumeric display CRTs are typically 5MHz bandwidth, also very often standard CRTs with no PDA so fairly low sensitivity, V/cm deflection.

I am assuming it is electrostatic?

Easiest fix is to simply use something like a 7603 with suitable amplifiers, 7A18 will do, to act as two differential inputs for X and Y. A third amplifier should do the Z. The 7603 (or whatever) has a large 12x10cm screen, whether that is large enough who knows. If you get lucky there is the HP 134S large screen scope.
AMR Labs:
Old thread but that not withstanding here is some info that might be useful on how to hook up an external scope to the R2001D to use as a screen substitute. I found this information on the Batlbs forum some time ago, but have not personally verified it. I only made a small correction bellow.

http://batboard.batlabs.com/viewtopic.php?f=1&p=203332&t=42545

Here is how I have connected an ocilloscope to the R2001.
The 'scope is used as a replacement for the CRT.
The scope must have X,Y,and Z inputs.

X=Vertical
Y= EXT Horizontal input.
Z= Blanking input, which is often found on the back panel of the scope.

The video will be inverted (negative) unless you construct a simple video inverter.

Connections to the R2001:

All connections are to test points on the A-2 board which is next to the CRT. The test points are in order as noted.
Also note that the LV supply will not operate with out the HV supply connected..

R2001A,B,C.
Vert: TP4
Horz TP1
Z (video) TP8
TP1 is toward rear of the chassis.

R2001D:
Vert: TP1
Horz: TP6
Z (video) TP 1 --> my correction: should say TP7

TP1 is toward the front of the chassis.
Set the scope for ext horz, set vert, and horz gains for the desired scan.

Adjust scope intencity, and 2001 intencity for adequate display.
The only R2001 front panel control which will be inop is the Focus.

helius:

--- Quote from: PaulAm on February 14, 2014, 12:58:15 am ---I like the CR70, it was built to minimize the possibility of damage to the crt, but it you want to see what you can do with equipment at hand, take a look here: http://www.ke5fx.com/crt.html

That page has some good links on CRT restoration.
--- End quote ---
The CR7000 (according to Sencore) is safer on newer or high-resolution displays because it has some restore cycles that are more gentle. It's also prohibitively expensive compared to the CR70. Has anyone modified their CR70 to lower its beam current?
ve3id:
I just saw this as I was looking for a solution to the same problem.
I have a Motorola R2001D/HS that looks like it may need the monitor replacing soon - has anybody found a solution?
Yes, I have confirmed from the manual that it uses X,Y, and Z outputs from card A2 in the service monitor.

I'd love to find a way of putting an LCD in there!

73 de Nigel ve3id
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