early modeline experiments

[Harry Dalek]

Assuming the opto-coupler arrangement works as mine did it should be able to handle 625 in monochrome, or anything less. There may be some phase issues at 4.43MHz PAL (or 3.58MHz NTSC) which might make colour a no-go, but it's no issue at the moment...

Oh that's pretty good ! impressive .

I had the same thing happen with some high-voltage diodes shipped from the US. They arrived in a box about the size of what you would put a pair of men's cowboy boots in! 10 diodes almost the same size, very slightly larger, than 1N4404s.

They sort of forced me to use the more expensive postage on the Led's no idea why ! very silly packaging as with yours

As I mentioned, I need to get on with this, but alas...

I wouldn't start building anything yet, it'll be the same principle, but otherwise could be quite different...just hang in there...I know you're keen to get on with it...

Steve A.[/quote]

I know there will be modifacations needed which need thinking out first .

[Harry Dalek]

...another thing I may have to look at is the horizontal deflection amplifier(s). Now the Horiz. is running at 6kHz the bandwidth may need extending, it is somewhat more than the usual 400Hz NBTV vertical rate...the vertical running at 25 or 50Hz should be fine as is. A rough 'rule of thumb' is a ten-fold bandwidth over the base-rate, so here, 60kHz.

Steve A.

I had a look this morning it still seems fine on 6KHZ i just have not tested it on the horizontal defection plates its on vertical scanning at the moment .
If it matters on this type of CRT swapping the deflection makes a difference ?

[Harry Dalek]

Harry, for the output transistors in the deflection amplifiers what can you get where you are? The usual MPSA42 in TO-92 packages may not be quite up to the task, What type of NPN high-voltage (300V+) transistors are easy to get where you are?

I think i still have a few ZTX458's I would have to have a look most of the time you have to order things like this on line

An ideal device is the BF585/BF587, these are not that common but I can get them here, I could do with a few myself, add a few for you and send them on. These are rated for 350/400V, more than enough, 1.6W (no heatsink) or 5W with heatsink. That amount of power, in both cases, is adequate.

I don't have any thing like that in that package here again it would have to be ordered ,like you have have parts laying around but higher voltage is a bit harder to get locally

The datasheet for the BF585/BF587 is attached, something similar is what I'm looking for.

[/quote]

Good to 110 MHZ i think i saw rated a lot higher to my little deflection amplifier transistors .
Yes Jaycar only have a few Transistor types over priced too i only go there when i know they have the part and i don't want to wait .
I have to do a search what's about Steve.

[Harry Dalek]

What I am considering is "A General Purpose Display", which would be consist of a conventional 5" CRT, in this case a 5ADP1, and only have inputs for X-deflection, Y-deflection and Z-modulation. No in-built timebases or the like, so it becomes non-specific to what application you may want to use it for. In a way akin to a PC display that can handle an array of resolutions and frame rates. Now this almost overlaps my desire to use a flat-panel VGA display in a similar manner.

I see that one runs at 3Kv that's what i had to use on the beast monitor ,so you thinking have any time bases fed to it to your needs at the time NBTV or what i am up to .

Quite honestly the VGA-type of route may be the easiest way to do it. Except some of the hardware may be difficult to source (fast RAM), but as noted above and in previous posts the 5ADP1 and the like also have complications....

The CRT is more fun the aboriginal people love using the word deadly in their sentence's and here it is a fact ...perhaps in electronics you should really have a range to work in those that stick to 12 v 5 v projects should learn and think what you can touch and what not to touch what the parts are rated at and what is needed to control things out side their comfort zone .

The VGA route also is safer, no high voltages, and no hassle with the CRT housing, deflection amplifiers, video amplifiers, etc. etc...

This is true very flat but !

I do intend to get a 5ADP1 display operational, but it may well be my last home-brew CRT display device. Perhaps a 5ADP7 version for SSTV too, which would be quite novel in 2023/4...the same chassis, same circuits etc. used, just swap the tubes (I have two NOS/unused of both) depending on application...

Steve A.

A novel idea you could do the side by side idea as here and share supplies ...once the mounting is done the rest is easier great idea Steve .

[Steve Anderson]

...A novel idea you could do the side by side idea as here and share supplies ...

The only thing there is it will be large, bulky and probably quite heavy with two 5" CRTs. OK if you have the space to give it a permanent 'residence', I don't. I also doubt that I'll use the P7 version that often. For SSTV I would probably use some form of up-converter, similar (but not the same) to the SSTV-625 version I did some years ago. The SSTV converter would be external to the display, i.e. the display isn't dedicated to any particular standard or format at all, it's a XYZ display. The only limitation would be the upper bandwidth of the deflection amps and the grid/cathode modulation arrangements.

It could be used as a low-bandwidth oscilloscope with suitable external pre-amplifiers and a timebase, though I have no intention of doing that.

This is what I have in mind for the BF585/587s I mentioned yesterday for the deflection amps...

Steve A.

[Harry Dalek]

The only thing there is it will be large, bulky and probably quite heavy with two 5" CRTs. OK if you have the space to give it a permanent 'residence', I don't. I also doubt that I'll use the P7 version that often. For SSTV I would probably use some form of up-converter, similar (but not the same) to the SSTV-625 version I did some years ago. The SSTV converter would be external to the display, i.e. the display isn't dedicated to any particular standard or format at all, it's a XYZ display. The only limitation would be the upper bandwidth of the deflection amps and the grid/cathode modulation arrangements.

It could be used as a low-bandwidth oscilloscope with suitable external pre-amplifiers and a timebase, though I have no intention of doing that.

This is what I have in mind for the BF585/587s I mentioned yesterday for the deflection amps...

Steve A.

Large and Bulky Yes i think it would have to be the size of mid teens this century desk top PC case, Big CRT big case 2 CRTs some times they just fit side by side with not much difference unless your custom casing .
Yes i know the problem of where to put something thing big ...anyway its always nice to see a old CRT used again so i will watch with interest .

[Steve Anderson]

...anyway its always nice to see a old CRT used again so i will watch with interest .

I suspect these CRTs were made in the early 50s, the boxes they are in are all original and were unopened when I got them, so the tubes inside are pristine. Unfortunately there's no date-code on the boxes or the tubes themselves...so after maybe some 70 years in 'storage' and being shipped (hand carried on a plane by me, UK to Thailand) here's hoping they're all OK. I have never 'fired them up' before.

In Europe they were known as DG 13-34 with a medium persistence green phosphor, or as a DB 13-34 with a short persistence blue phosphor for photography. In the US they were available with a P1, P2, P7 and a P11 phosphor.

I guess for a single-tube version it would be like half of an old IBM 286 desktop PC in size. Think of PCs around 1980...but I'll get my user-friendly 'metal-basher' to knock up a case/chassis to suit. Similar to that below but around half the width and the transformers moved to a separate box on a 2-3m umbilical to remove their magnetic fields.

Note the tubes/valves around the 5ADP1 base, these were for the deflection amplifiers, 4xEF91/6AM6s. I might be tempted to repeat the idea - bandwidth permitting...but knowing me, I'll probably stick with semiconductors...

Steve A.

Initial 2.jpg (179.88 KiB) Viewed 4095 times

[Harry Dalek]

I suspect these CRTs were made in the early 50s, the boxes they are in are all original and were unopened when I got them, so the tubes inside are pristine. Unfortunately there's no date-code on the boxes or the tubes themselves...so after maybe some 70 years in 'storage' and being shipped (hand carried on a plane by me, UK to Thailand) here's hoping they're all OK. I have never 'fired them up' before.

They made things to last back then will there be a 70 year old flat panel still working one day ?

In Europe they were known as DG 13-34 with a medium persistence green phosphor, or as a DB 13-34 with a short persistence blue phosphor for photography. In the US they were available with a P1, P2, P7 and a P11 phosphor.

P1 this one and green phosphor yes i suppose if not make for Television no B/W versions .

I guess for a single-tube version it would be like half of an old IBM 286 desktop PC in size. Think of PCs around 1980...but I'll get my user-friendly 'metal-basher' to knock up a case/chassis to suit. Similar to that below but around half the width and the transformers moved to a separate box on a 2-3m umbilical to remove their magnetic fields.

I have the vision of a fellow with some steel panel between hes toes ~! Yes that would drop the size easier to build the case for that fellow !

Note the tubes/valves around the 5ADP1 base, these were for the deflection amplifiers, 4xEF91/6AM6s. I might be tempted to repeat the idea - bandwidth permitting...but knowing me, I'll probably stick with semiconductors...

Steve A.

Initial 2.jpg

[/quote]

[Steve Anderson]

P1 this one and green phosphor yes i suppose if not make for Television no B/W versions .

No P4 (White phosphor) versions or the Euro equivalent versions I'm aware of. To get these P4 versions you're looking a 7" or more. Even those with electrostatic deflection were rare then, today - forget it. One guy I connected with in Europe was able to find an electrostatic 9" P4 CRT from the US. He paid the 'going rate' for it. When it arrived the neck was broken in two. Thanks whoever the shipper was...

Years ago in the UK, if you sent something by rail marked "Fragile", the only difference was the staff would watch it bounce...

Steve A.

[Harry Dalek]

P1 this one and green phosphor yes i suppose if not make for Television no B/W versions .

No P4 (White phosphor) versions or the Euro equivalent versions I'm aware of. To get these P4 versions you're looking a 7" or more. Even those with electrostatic deflection were rare then, today - forget it. One guy I connected with in Europe was able to find an electrostatic 9" P4 CRT from the US. He paid the 'going rate' for it. When it arrived the neck was broken in two. Thanks whoever the shipper was...

Years ago in the UK, if you sent something by rail marked "Fragile", the only difference was the staff would watch it bounce...

Steve A.

OH thats nice never had one of those just magnetic deflected tubes every thing else green.
That's a disaster ! i did get an NTSC portable set from the USA in the later 80s and it came in the same state looked to have been dropped from a height i knew this was not good when i could hear the glass in the box