Products > Test Equipment
Replacement for CRT?
<< < (4/5) > >>
AMR Labs:

--- Quote from: ve3id on June 26, 2022, 05:52:25 pm ---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

--- End quote ---

What are the symptoms of your CRT? Have you checked what brand your R2001D has? It seems the american made one (Magnavox) is the worst offender. The AEG/Telefunken rarely seem to have any problems unless really at end of life. Also some persons report that rejuvenating seems to prolong useful life as well. Not sure if that applies to all 3 brands of CRT.

Mine behaves quite well with decent intensity and focus stops drifting after about 5 minutes of warm up, so still quite usable.
Also during warm up if I turn down the intensity the screen background actually lights up, if I go up on intensity then the characters actually get somewhat brighter but loose a bit of focus as well.
There seems to be a middle ground setting that works best, and that point also drifts a bit until the whole thing warms up properly.

LCD, I don't think so far there is anything out there that can be used as a direct replacement, but have not checked for some time. Wish someone would come up with one that works decently and preserves the resolution and screen reaction time of the measurement bargraphs. Nothing like the good old CRT.
TomKatt:
Just an idea to cover worst case scenario of original crt inoperative and no replacement available...   You could work your way back up the XY chain to the lower level analog signals (instead of the high voltage plate drivers) and use an oscope to display the vector signals.  I owned an Atari Tempest game for a while and was able to play the game on my scope by that method.  You'll need a decent analog CRO in XY mode for this to work, digital scopes don't process XY fast enough.  I don't believe I've ever seen any type of vector to raster converter, so it's unlikely you could substitute an lcd display panel in that gear.
ve3id:
Thanks TomKatt and AMR Labs,

The only symptom I am seeing so far is jittery screen position, and yes, I know this is most likely a dirty pot.  However if I am going to open it up I want to be pro-active and replace the CRT since I want to get many more years from this.

The A2 card, somebody previously said, does have low-level X,Y,and Z signals that could drive something if I can find an LCD that can work from them!

As far as scoping with an analogue scope goes, that might be an adventure since its own display was fading when I put it in the back closet and bought a Keysight digital scope a few years back!

I was really hoping to find somebody who has done it!  There is one co I found that specialises in replacing CRTs in industrial panels but I think their prices would be more that a new CRT!


TomKatt:

--- Quote from: ve3id on June 28, 2022, 12:45:39 pm ---There is one co I found that specialises in replacing CRTs in industrial panels but I think their prices would be more that a new CRT!

--- End quote ---
I believe you will find that any CRT conversion is based on raster type displays...  It's nigh impossible to convert vector signals to raster format needed for lcd panels.

I play around with vector stuff pretty frequently - I'll keep an eye out for any possible CRT's that might fit your application.

EDIT - poking around the interwebs I discovered https://wiki.w9cr.net/index.php/Motorola_R2001D#Scope_conversion, which lays out how to use a scope as a display for the R2001D.   In addition to an analog CRO, gear like old Tek vector monitors used to be cheap and available on eBay - these work equally well, if not perhaps better.
AMR Labs:

--- Quote from: ve3id on June 28, 2022, 12:45:39 pm ---Thanks TomKatt and AMR Labs,

The only symptom I am seeing so far is jittery screen position, and yes, I know this is most likely a dirty pot.  However if I am going to open it up I want to be pro-active and replace the CRT since I want to get many more years from this.


--- End quote ---

The problem with the CRT usually involves the trace getting very dim, so if yours has no problem there, your CRT should be fine. Besides you cannot just replace the CRT very easily, you have to find one first which is very difficult (and expensive). If you find one just keep it on hand until its needed. Over the years I've seen them come up sometimes but very rarely. Now regret not having purchased one of those as a spare back when. In any event its a good idea never to leave the screen idle for long periods of time, if you need to keep the service monitor powered on then just turn down the intensity to zero and that will save you CRT life.

Is the CRT position jittery only when you turn any of the screen related controls? If so the controls just might need a bit of lubrication/cleaning, which is not uncommon in this instrument. Do not use contact cleaner on the potentiometers, use Deoxit fader lube (light green liquid). Also do not use Deoxit red, that is meant for switch contact cleaning. If CRT position is jittery by itself, perhaps the CRT power supplies may need some attention. Lube the pots first, or sometimes by just excercising them a bit cures the problem by removing any oxide that might have formed on the track or contact finger. As I remember getting to the pots involves removing the whole front panel which is a job in itself. I still have to replace the RF Scan control in mine which sometimes works, most of the time it does not, but I have a spare encoder. One of these days will get to it.

The detailed instructions on how to adapt a scope as a display alternative are in one of my previous posts above, and also a link to the original post at Batlabs.
Navigation
Message Index
Next page
Previous page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod