HP8592A Screen Help

[Telecom Green]

Originally Posted by Julesomega

There are 5" screen display units for use with vehicle reversing cameras, they take a video input on a single RCA Phono jack and will also allow you to watch DVDs (just need a small 6–32V dc supply unit). Several from ~£12.50 on eBay

Will plugging it in the back of an elderly CRT-type telly not work? We keep one for playing old VHS tapes.

[Julesomega]

Should do - try it out! I was thinking more about selling the SA with a small external screen.
I've now found the 4½" display unit and camera I bought last year for seeing round corners
Will try it out tomorrow

[Radio Wrangler]

Originally Posted by Julesomega

That's wonderful news for me too, as I have an 8563E which I'm supposed to be selling for a colleague but you have to wait for nighttime before you can read the display. Should be able to feed the composite video into an older flat screen TV via a SCART adapter I've got somewhere.

You seem to have got it the wrong way round.

The 859x family of analysers are the ones with raster scan TV compatible displays. The internal CRTs in these are very long lived. Display electronics sometimes fail, but it's essentially a TV fixing job.

The 856x family of analysers, like your 8563 use analogue X-Y displays and draw everything as vectors. They are NOT TV compatible. CRTs for these grow dim and are pretty much irreplaceable, all spares long used-up. Search for LCD upgrade kits and have your bank primed.

What sows confusion is that in spectrum analyser-speak, the word 'video' is also used to refer to the analogue signal out of the logarithmic detector section. (The signal destined for Y plates on a pre-CPU analyser) Both analyser families have this as an output, labelled 'video' Vertical deflection would have been a far better name.

David

[cmjones01]

Originally Posted by Julesomega

That's wonderful news for me too, as I have an 8563E which I'm supposed to be selling for a colleague but you have to wait for nighttime before you can read the display. Should be able to feed the composite video into an older flat screen TV via a SCART adapter I've got somewhere.

The 8563E won't work with a standard external monitor, as I understand it. The 856x series use a different kind of display to your 8592A.

Chris

[Julesomega]

Thanks for the valuable update re my 8563E. Pity, I'll have to offer it with a free set of dark curtains

[Radio Wrangler]

The 8563 is still a very good analyser even with a dead CRT.

Nicest fix is an LCD kit (HP released a late model with LCD, but as rare as.... Though there are aftermarket ones.

Minimalist work-around is to leave CRT and use software like VEE or labview to suck traces etc via GPIB and display on computer.

Mild work-around is to go inside and nobble X, Y, Z signals and display on a scope. Scope graticule becomes a nuisance but you can find X, Y, Z displays without graticules. You can even find displays with the same tube as the 856x analyser and do a transplant. I have one in the attic as a spare for my 8566B, and I have one out at the museum as a spare for theirs.

The plant which made these CRTs was at Colorado Springs and was shut down around about 1990. I believe the building was demolished. In the later 90's HP was still making 6x analysers, but I understand they were sourcing CRTs from Panasonic. The CRT plant belonged tothe scope division and they'd gone over enirely to digital architecture and magnetic CRT monitors. The spectrum analyser division felt they'd been shafted, but they'd been trampled simply because their needs were small compared to scopes and they simply got ignored. Inter-divisional politics in a large empire can get, um, lively.

David

[Telecom Green]

Hello Folks,

I'm currently still trying to find a loving "forever home" for the 8592A mentioned in this thread.

I've tried to connect an ancient TV CRT monitor, but with no success, the reason being that I only have domestic-type co-ax leads. The ones on the back of the device have a small raised tag. Excuse my extreme ignorance (again!), but are these a standard BNC, or something else? I must have dealt with several hundred BNCs last 25 years in my comms recycling business, particularly in respect of ISDN feeds to PABX, but I've suddenly gone a complete blank.

The next challenge is finding an alternative to the dead CRT small TV which I'd hoped to connect simply via co-ax. It does not power up. Meanwhile, I have several PC monitors with VGA connectors. Can anyone recommend a suitable BNC to VGA connector/convertor?

Meanwhile, what should I be able to see on the screen of my external device to indicate health of the unit?

Thanks in anticipation for your continuing kind help as a group!

Rob

[Radio Wrangler]

Originally Posted by Julesomega

That's wonderful news for me too, as I have an 8563E which I'm supposed to be selling for a colleague but you have to wait for nighttime before you can read the display. Should be able to feed the composite video into an older flat screen TV via a SCART adapter I've got somewhere.

No. You haven't been reading the thread! The 856x family are the ones with vector graphics and do NOT have the TV format monitor output.

The 856x family, which your 8563 (all suffixes) is part of, uses vector graphics and can only export its picture to an analogue XYZ crt display.

The TV compatible outputs and raster scan magnetic deflection CRT are in the lower cost (and in some ways lower performance) 859x family (all suffixes)

David

[McMurdo]

you're going to need a tv with composite input and appropriate inter-series adapter. I dont think you'll have much luck connecting the HP BNC to the aerial socket of a telly.
Buying a composite to VGA upscaler sounds a bit extravagant a purchase just so you can use a computer monitor to test it.

[Telecom Green]

Thanks very much for the information.

I've probably spent enough time investigating this equipment, and have reached the limits of knowledge and time.

I really do need to put it up for sale "as-is", with the guidance that the screen has shown some life, and that there have bveen no pops, bangs or puffs of acrid smoke on power-up.

Can any honourable members give any pointers towards realistic price?

Thanks in anticipation for your kind help.

Rob

[Radio Wrangler]

I've seen working '9x' family analysers in the £800 and upwards price range, somewhat dependent on the frequency range, but oddly not reflecting what options are fitted. Tracking generator, narrow IF bandwidths, ovened freq standard, AM/FM demod, all greatly increase the usefulness these instruments.

The 22GHz '6x' family of analysers get offered from time to time by Stewart of Reading in the £2000 region.

For a non-working one, it depends on how scary people think the symptoms are.

The CPU card is the big one with the battery mounted on it. I think there is a bad chip on it. Possibly a logic device, possibly a memory device, but likely findable with a scope and a probe. A modern digital storage scope would be good, but the waveforms involved are repetitive enough for a conventional CRT non-storage scope to do the job. Anyone who has some familiarity with these boxes would not be too intimidated.

David

[Telecom Green]

Folks,

I have now offered this item in the "Items Offered" section.

Rob

[PETERg0rsq]

I have now taken on the repairs to this spectrum analyser after the purchase from Rob (many thanks).

Initial investigations are centered around the display board, which utilises a HD63484 display processor.

I have spent a few days and reverse engineered the board and produced a schematic for it.

It looks like it updates 4 DRAM chips, two for trace and two for text and a parallel to serial converter for each output.

These are then combined and added to the NTSC timing elements to generate a TV picture.

I have established that the interference on the screen is generated in the TEXT generation of the system.

I now need to find how the TEXT character are generated as the HD63484 is directly communicating with the main CPU on the CPU board.

I now need to make up a jump lead to run the display board outside the 8592, so I can connect my logic analyser to the DRAM. I can then check they are not corrupting the TEXT character display, before learning how the HD63484 graphic processor works.

I was planning a full factory reset on this, (a cold restart resetting all the memory to default) but there is no internal CPU battery to pull! And without reading the screen can not use the menus to do this

This looks like the most challenging project I have done to date

[Radio Wrangler]

You're on the right track and going well.

David.