Did anybody try to replace the CRT on the HP8590 series with LCD successfuly? It has a monitor output and NTSC or PAL options but no one seem to be standard resolution. I bought a 5" LCD from ebay and it has CVBS and VGA inputs. It works beautifully from a PC with 640x480 but I can't get it to work acceptably with the SA. The sync signals seem to be totally non standard. Apart from re-clocking it with an FPGA, which may not even work in this case, do you have any idea how to do it? I don't think I can take on an FPGA project. I've attached some sync screen shots for the default sync on SA and VGA 640x480 @ 75Hz.
You may want to have a look at the GB8220 video converter card. It will take CGA, EGA and other inputs and output at VGA and various resolutions. More importantly, you can adjust timing. It's a bit fussy to set up but you see immediate results from your change of settings.
I used it to create a nice 800x600 panel output from oddball sync and separate video from an 8753C network analyzer. I believe I also had it driving a 1024x768 panel.
The card is cheap and powerful. Check ebay if you're interested.
Like you, this would have been a good FPGA project but no time
I agree with EE-Digger. I used a GBS-8200 to replace the CRT in an 8752C with an LCD. That doesn't mean it will be compatible with an 8594E but it may be worth a shot.
Thanks, that is an interesting board. I see that it doesn't have CVBS input so should I use monitor output to the Y input and leave the PbPr unused? Or maybe go from the internal display connection that has YHV through VGA input connecting all three colors together. It may work.
On ebay, they're all over the place with the description of this board. Pictures combined of a GBS-8220 V3.0 and an HD9820, packing list GBS-8200. How many versions of this board are there?
I have to apologize. This is the second time I've recommended this board and I just noticed that it does not seem to have a composite input. I used it around 3-5 years ago with RGB inputs and separate sync (to which I had to add a sync separator chip).
But I have output my 8596E NTSC video to a Panasonic 5" BW pro video monitor and it gave a nice little image. Yet the same signal input to Sony professional monitors was unable to produce a good picture.
I think your scope images sum up the reason for this.
What you may want to consider is to strip off the sync, change the timing of it, then recombine with the video. The alternative is to "play", and I do mean play, with some of the composite video to flat panel controller boards.
I've been thru several of those and non were shining stars
Don't apologise, it does have YUV though and that should be good enough. Y carries luma and sync and I don't need colour anyway. The output to the CRT module has separate sync so from separate sync, default sync, NTSC and PAL, one must work so I ordered one.
I also made some progress using the monitor output. I "discovered" that it has horizontal and vertical position adjustment in the CAL menu. In PAL mode it is almost perfect horizontally but vertically it doesn't fill the display completely but it is usable. In case my green CRT dies, I have a solution. GBS-8220 having size adjustments (I understand) could make things perfect.
The GBS8200 does allow for quite a bit of correction/adjustment. You can change output resolution, adjust location and the size - you might want to order one just to play with.
Here is a 1024x768 LCD installed in my HP 8752C network analyzer.
I ordered one yesterday thinking it has YUV input but now looking at some manuals found on the net I think more and more that in this case YUV is the Chinese translation of YPbPr. Do you know if it accepts indeed YUV?
It gets even better...well, almost. If I reduce the video level with a 1K potentiometer, at one point I get some gradient on the graticule intensity as it should be since the video signal has two levels, high for the trace and markers and lower for everything else. Unfortunately, the video level where this happens is way too low in my opinion.
Did anybody try to replace the CRT on the HP8590 series with LCD successfuly? It has a monitor output and NTSC or PAL options but no one seem to be standard resolution. I bought a 5" LCD from ebay and it has CVBS and VGA inputs. It works beautifully from a PC with 640x480 but I can't get it to work acceptably with the SA. The sync signals seem to be totally non standard. Apart from re-clocking it with an FPGA, which may not even work in this case, do you have any idea how to do it? I don't think I can take on an FPGA project. I've attached some sync screen shots for the default sync on SA and VGA 640x480 @ 75Hz.
Would you mind sharing, or messaging a link to the display you got?
be carefull not to blow your converter,
the gonbes boards dont tolerate TTL sync pulses - max input is about 3v
be carefull not to blow your converter,
the gonbes boards dont tolerate TTL sync pulses - max input is about 3v
Thanks for the info Stj! How do you know this? I looked through some manuals and I didn't see that.
Do you know what chip it is?
i think it's mentioned at that link.
https://www.ebay.co.uk/itm/VGA-AV-LCD-controller-board-with-5-6inch-640x480-AT056TN52-lcd-panel/251590018265?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649
I bought this module a week ago & it arrived today. A very quick hook up suggests that this one may be a good option. Proper testing will take a little longer!
Phil
Yes, I was looking at that (or similar) LCD, my 5" is too small. Did you connect it to the monitor output?
Could you please do some tests?
1. Go through all three video modes, default sync, NTSC and PAL and see if it syncs in all three.
2. Try to center the image using the CRT Vert and CRT Horz position in CAL menu. See what the adjustment range is.
3. Place the front mask on top of the LCD and post some pictures. I want to see if the image fits inside the mask and if it aligns with the right hand buttons and also if the aspect ratio is correct, if the grid is square.
I received my GBS8220 and is not really usable. In YUV mode it only synchronize in NTSC (I think YUV is an NTSC only thing) and passes the signal without processing, meaning that there's no geometry adjustments. IN RGBS it has geometry adjustments but I would have to strip the sync pulses from video and again it only works in NTSC.
The problem with it only working in NTSC is that, if by accident you set it in PAL or default sync (whatever that mean), you may have a hard time setting it back to NTSC.
A quick look & I can start to answer your questions.
It only works when the SA is set to PAL.
The display bezel will need to be trimmed a few mm on each vertical side for the full display to be viewable.
The button legends do align well with the buttons
The hor. & vert. adjustment controls will centre the display correctly.
LCD fixing? That is a question for another day. Probably if I ever get the faults in the 3off 8596s & 1off 8593. I got these plus a very large heap of test gear from a company closure & have spent the last 4 months quietly sorting various instruments to keep & sell the excess ( a lot according to my wife has still got to go). I cannot resist the urge to buy any test gear that is interesting & the more there is the better I like the deal.
Phil
Really, the vertical doesn't fit? I was expecting the horizontal. Mine works best on PAL too even though it syncs on NTSC as well.
Thanks Phil, I think our best bet would be to recap the CRT module when it fails and readjust it as much as we can.
Weird implementation eh? I wonder why did they choose such non standard timing. CGA, EGA, VGA must have been invented already.
Sorry, I was not clear. Trimming the verticals on the bezel increases the horizontal Not sure that recapping the CRT module will solve all my display problems as I have at least one dead CRT. Much more work needed before I need to actually start cutting metal to get the LCD fitted.
Phil
Are you sure the CRT is dead. I repaired three CRT modules, all with dry caps. My CRT has burn marks but is still functional.
One may be the caps failing a it takes a while to actually display anything on the CRT plus the whole image starts very large & unfocussed before settling down to a nice sharp & bright image.
The other is a dead CRT unfortunately. Thanks for the suggestion.
Phil
I'm having a similar issue with an LCD monitor on the composite video output of my Anritsu MS-420K. The image on the LCD is shifted up and to the right, clipping off the top line of the display. The Super Circuits LCD measures 5.6" diagonal. Sadly, its menu has no adjustments for size or position.
I've emailed several sellers of LCD panel+controller combos on eBay, asking if their unit offered those adjustments. They all said no.