HP Agilent Spectrum Analyzer 859X LCD display

[charlyd]

hello i am getting a 8595E with a bad display as far as i could see.  I was thinking about fitting an LCD myself in there. what resolution is orginal tube picture and what is the size from the screen. so i can look arround

can anybody help me to that info.

[tkamiya]

This is one of them....

https://www.ebay.com/str/newscopelcdkits

I have not purchased or converted mine.  So I have no impressions or reviews.

[james_s]

It's a standard NTSC resolution monitor. I would take a look at the original monitor before condemning it, they are not complicated and unless the tube is completely worn out they can usually be repaired.

[charlyd]

i was just looking for a cheap LCD replacement  but really is it NTSC ?  no PAL?  or just 640x480  800x600 ?

[Bicurico]

The linked screens at ebay are more than just a screen. They contain a controller that can interpret brightness and convert it to colour. I find them quite expensive though.

You can use any LCD with composite input. Route the composite video on the back.

The problem is that you need a 4:3 ratio LCD with the correct size. You will have a hard time matching the softkey positions.

I think it would be better to repair the CRT or get a replacement.

Regards,
Vitor

[james_s]

i was just looking for a cheap LCD replacement  but really is it NTSC ?  no PAL?  or just 640x480  800x600 ?

Technically NTSC refers to the color encoding while the 859x instruments are monochrome so it's not true NTSC but it is monochrome baseband video with a 60Hz frame rate and 15.7kHz line rate, technically I think it is something like 512x384 and there is a standard composite video output on the back. Remember that these instruments were designed 30+ years ago when 640x480 was considered high resolution and you could still buy personal computers that used analog TV sets as monitors.

Given it's only about 5" I find that the monitor is quite adequate, mine produces a nice picture with sharp legible text despite the low resolution by modern standards. Personally I think the green CRT looks cool.

[charlyd]

hello first i hope somebody will hook on this topic with a 3D printer.

i want to look serious for a bigger LCD screen i saw there is space maybe for 7 inch or 8 inch. i have to dive into it and i will. the Original crt screen is so 1920's .
the "grey" crt frame with the six button membrane button on the right side can be replaced with a total new design, maybe, need some investigation
i saw when i took the 4 screws of the frame there are just 6 switches which with the right pushbuttons caps could stay, not?

is there a way to re-design a new frame and create it with a 3D printer.
or do i need to make a proto type plexi panel?

ok first find the right screen.  so specs please.. 
4:3
ntsc ?
7 inch or 8 inch?
can it be a color lcd or do i need sort of monochrome


i did the first quick filtering

4:3

320×240
384×288
512×384
400x300   
640x480
800x600
960x720
1024x768

just 1 or max 2 will fit i think.
 

[Miti]

It is not standard NTSC sync, take a look here:

https://www.eevblog.com/forum/testgear/hp-8594e-replacing-the-green-crt-with-lcd/msg1619449/#msg1619449

Those AV 640x480 LCDs sync only when PAL is selected. The one I have doesn't sync on NTSC or NORM.
I have an 8591E and an 8594E, both with burn marks and tired CRTs. I did quite a bit of research and I found a viable solution, but in the end I decided to recap my 8591E and see if it makes any difference... visually, it doesn't, telling me that it is the display. With few (essential) exceptions, the caps were in pretty decent shape, ESR wise. For now, I will keep the LCD as a disaster recovery solution, in case the CRT dies or becomes unusable... or someone comes with a chic idea and I like it.
The right size would probably be 5.6" for the vertical to match the buttons exactly, but horizontally, would go out of frame a bit as we don't have geometry control, only H and V position in the SA cal menu. A trim in the front frame would solve that though and that would be easier and look better than 3D printing.
I think I even know a way to make it green if I decide to exercise my paranoid personality (ground the red and blue inputs to the LCD) but I haven't validated that yet.
The only way to make it right is how newscope-OJr did it, with an FPGA, but 370$? No way I would invest that money in a dinosaur that can die next week.
Another solution would be a community project but I don't think there's much traction with quite few reasonably priced new SAs on the market.
I could do the HW but I'm not there with coding in Verilog/VHDL.

[charlyd]

Hi Miti , i am happy you responded to this post i saw many post you talked about and did a screen swap. and yes it looks good. But woudn t it be nice to go for bigger size. ;-)

what about the composite video signal on the back ( assuming the [monitor out] is CV of course, i didn t dive into yet) isn t that usefull as a start?

[james_s]

Why would you want a bigger display? Have you ever even used one of these instruments? The display is as big as the opening for it in the front panel and the softkeys along the side line up with the text on the display. Fitting a larger display would require substantial modifications and you'll have a hacked up molested instrument. If you want one of those stupid LCD displays that everything has now, just buy a more modern spectrum analyzer. The 859x instruments are designed around a 5" CRT and it works well, there's absolutely no reason to trash it with silly modifications.

[charlyd]

you are right about the alignment of the buttons, that can be an issue, for the rest is it personal i think. One love the CRT the other doens t, in those days it was more a must then a want, there were no LCD for todays prices. Apart from that after 30 yrs the burned in crt doesn t make things happier ;-)

[charlyd]

@miki what was the reason for adding the resistor on the video board of the SA in the newscope manual. ahhh shift half brightness for color mapping.

[Miti]

As I said , I did not swap yet, both instruments I have still use the CRT display. It was just an experiment in search for a  viable disaster recovery solution. I guess the extent of changes that you are willing to make, is a personal choice indeed. Personally, I don’t see only the functional side of an old instrument but also it’s personality, if that makes sense. If the modernization can blend nicely in the “landscape” I would do it, otherwise I try to stick with the original design... like a good architect that would never raise a sky scraper beside Louvre... for example. 
Beside, there’s not enough resolution for a too big display. If my counting is correct, it is 512x255 or so. A big display wouldn’t bring more information and would look grainy, even though my aging eyes scream for big.
I’m tempted to buy a 5.6” just to see how it aligns with the keys. The front plastic frame needs about 3 mm horizontal trimming, which probably is barely visible.
The video output on the back has the same timing, it just combines the sync and video, and you don’t have control over the levels of brightness... well, you do, but in a different way, different resistor.

[charlyd]

ah thanks for the info. i was just curious in the possibilities. and one of them is  did someone every tried the (grey) frame from the 856X series fits in the 859X series.
i mean the screen size looks a small bit bigger. but does it fit are the screw holes and switches on the same place and so one.

you talk about  512x255  but i dont undertand this is not really 4:3 what do you mean with this resolution.. sorry to ask maybe stupid questions i did not investigate yet..

[Miti]

you talk about  512x255  but i dont undertand this is not really 4:3 what doe you mean with this resolution..

No, it is not. And it is possible the reason why the display doesn't sync in NTSC. If you look at one of my pictures, you'll see that the image on the LCD is compressed vertically, it doesn't completely fill the screen.

[charlyd]

@miti, so 4:3 is not the right resolution. We have to translate 512x255  as being the real resolution?  is that what you say?
                                                         Where did you get this   ^^^  resolution value from?

i tried to look in the other topic for the screen with vert. compressed problems?  i can not find it straight away.

did you see my question about 856X bezel fitted in the 859X ?

so i undertand you want to go for 5.6 inch screen for better fitting.
i contacted a big chinese LCD manufacturer to help thinking and it is working out but that was all minded to 4:3 so.. start over.

For sure want to go to a LCD, because the green crt is terrible to look at and it is slowly stopping to start up smooth.
 

[Miti]

@miti, so 4:3 is not the right resolution. We have to translate 512x255  as being the real resolution?  is that what you say?
                                                         Where did you get this   ^^^  resolution value from?

From the oscilloscope, counting the sync pulses.
The CRT is 4:3 so technically the LCD must be 4:3. On the CRT it is easy to stretch the image vertically a bit, on the LCD is not that easy if you don't have geometry control. If you try a different aspect ratio, like 16:10, you'll have a bigger problem, so stick with 4:3.

did you see my question about 856X bezel fitted in the 859X ?

Yes, I have an 8561E at work, I could measure but first of all, if you can get a front frame for 856x it is probably expensive, and I don't think the keys will match. Second, the biggest size that you can squeeze in the aluminium frame is 6", and I couldn't find a suitable LCD with that dimension. Stick with 5.6", take a look at this:

https://www.ebay.com/itm/For-5-6inch-640x480-AT056TN52-V3-4-3-LCD-Panel-VGA-AV-Driver-Board-100-working/143469305538?hash=item21676fdec2:g:vCgAAOSwZb9d8av0

For sure want to go to a LCD, because the green crt is terrible to look at and it is slowly stopping to start up smooth.

I strongly disagree. Green is known to be a relaxing colour, easy on the eyes, and I don't see any issue with the CRT on your SA.
In the past, many cars had green dashboard back light. Recently they gave up that and installed, red, orange and even the awful... blue.
If I drove 100Km with a blue dashboard in front of me, I'd go berserk.
I assume you are very young and you don't know what I'm talking about...

Edit: Damn it, charlyd, you made me buy one of those LCDs. 

[charlyd]

i have added some aspect ratios as an attachment. Just the front bezel is not so expensive. i mean the grey plastic frame+glas if needed. the viewable size is just a bit bigger from what i see( just a guess) i asked the seller the put it on the old bezel and send some pictures of them both. will share them. i also want to know if the 4 corner holes are also exactly the same.

[Miti]

i was just curious in the possibilities. and one of them is  did someone every tried the (grey) frame from the 856X series fits in the 859X series.
i mean the screen size looks a small bit bigger. but does it fit are the screw holes and switches on the same place and so one.

So guess what I did today. I took the display frame from the 8561E and I measured it and drew its contour on a piece of paper. Then I compared the drawing with my 8591E frame. They are identical except for the opening which is bigger. 
So if you can find an LCD module that fits in that frame, and can live with totally misaligned keys, go for it.

[tkamiya]

I have a similar specAn also.  There is a selectable option to switch between PAL and NTSC.  I also have an LCD display that can go between PAL and NTSC.  I could not find a single combination that worked.  I can get something to display but always some part of the image was chopped off.  Also, I could not get a clean display.  It resembled how old APPLE II display looked when fed into an NTSC monitor.

Before making drastic modification, please make sure it is working to your satisfaction. 

My display happens to be in pretty good shape.  But if not, I'd be happy to pay the LCD guy on eBay what he is asking.  It is a complete kit.  No added knobs and after-thought-looking implementations.  The end look appears factory fresh.  He spent a lot of hours on these.

[charlyd]

hi jus a few questions..   miti you say the bezel is the same .. so will fit.. your 5.6 " inch model is that the  viewable dislay size whch fits in the 856X bezel and gives a bigger screen look?

the other question is you both tell me the picture doesn t really fit or is not in it Original format.  what exactly happens. iwill ask the manufactorer of the lcd how or where to get this adjusted.. maybe the controller need some extra components....will work that out if i know where the picture goes wrong.

i saw the picture from MITI on the other topic and couldn t find the real mismatch. can you post the picture here from your lets say "best" output

[Miti]

Here's a dimensional comparison between the two bezels. As you can see everything is identical, including the color, with the exception of the display opening. However, the 5.6" LCD will fit inside the 8590 bezel, if I file it (or better mill it) to increase the horizontal opening by about 3mm, which is not a big deal, 1.5mm each side.
I played a bit more today with the video levels, I changed the resistor parallel with R301 from 390R (recommended by Newscope-OJr) to 220R and the separation between half brightness and full brightness is more evident. The camera kind of levels out the brightness but you can see there's difference between the grid and the trace.
Visual is even more obvious.
I don't know what mismatch you are talking about, but if you look at my previous pictures and the one that I attached now, the horizontal almost fills the active area of the LCD but vertically, there is some empty space top and bottom. Also, the grid is not square, which doesn't really matter since there doesn't really need to be a strict geometric correlation between vertical and horizontal.

More I refine my solution, more I feel like upgrading.
Last weekend I checked if I can hack the LCD to eliminate some colors and it works. Removing (or lifting) and grounding one side of the resistor networks that are series with the blue data bus from the LCD driver board to the LCD module, gave me a nice yellow display.

Edit: If you look at the picture "Figure 4 8590E Color Scheme #2" in the NewScope-0Jr_OM.pdf, it doesn't look any better than mine. Unless you use an LCD module with a resolution that matches the specs of the input signal, you'll always have interpolation.

[charlyd]

Hi Miti, you did great work..  next week i order a bezel ( if i can find a 6.0 inch lcd)  but i was also looked at the glasses in front  the 859X has plastic... where the 856X has glas..
i don t know what sort of glas but..

i found screens from 5.7 and 5.8....but matching the 5.9"  mmmmm 

i mis understood you i thought there where problems with the pal/ntsc or sync in one way.. but it is not and for this vert. sizing is no problem for me as not for you.

if i find a fitting lcd i will resize the frame to fit to the lcd.

[Miti]

i found screens from 5.7 and 5.8....but matching the 5.9"  mmmmm 

Keep in mind that the bigger the LCD, the more misalignment you have between the physical keys and the soft keys on the screen. See below. This module is 5" so if you use 5.8" or 5.9", your soft keys will be stretched relative to the hw keys. I strongly suggest you stay with 5.6" or close. I will know more once I receive my 5.6" module.

i mis understood you i thought there where problems with the pal/ntsc or sync in one way.. but it is not and for this vert. sizing is no problem for me as not for you.

if i find a fitting lcd i will resize the frame to fit to the lcd.

There are, the LCD only works in PAL mode. That may be an issue if, by mistake, you select NORM or NTSC...You'll have to blindly press a sequence of keys to go back to PAL because the screen is scrambled.

[charlyd]

Miti ok so the pal setting is a issue.  but if i look at your picture the bigger the screen, the better aligned with the buttons from what i see now.. i mean if the screen is bigger the bottom button text goes more down and top button tekst up. that way your red line are more horizontal.  am i right with this conclusion.