Frame Sequential Cathode Ray Tube Project

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Happy so far

Postby Harry Dalek » Mon Aug 13, 2018 10:57 pm

Just a little more information on the switching board i needed to get some thing down as a schematic for me memory fades with to much wiring and i didn't make it easy on my self doing all 3 FSC systems .
i forgot to put in the middle row of 7490 ics out put the 30 hz for the video FSC switching of the video ic6....the 37.5hz comes from my first board with the 1.8mhz clock
Any case i have to update a schematic for the 10 hz side of it
The last switch on ic4 and first on iC5 4066 is for the 10Hz 12.5Hz switching ,the last 3 on ic5 are for FSC video switching to the video amp circuits then to the Trinitron cathodes .
Edit updated the picture circuit ic numbers
Attachments
addtext_com_MDYwNTQ4MzI2OTY.jpg
addtext_com_MDMzNzE5MjUwODA.jpg
Last edited by Harry Dalek on Wed Aug 15, 2018 6:42 pm, edited 1 time in total.
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Re: Frame Sequential Cathode Ray Tube Project

Postby FlyMario » Tue Aug 14, 2018 4:03 am

I have to look at this deeply sometime. I am fascinated that you are using Decade counters. I am always puzzled by doing that instead of using Binary Counters. I thought maybe you are making a DAC to control the horizontal and vertical position. But seems that binary would be more logical. So I must be way off :)
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Re: Frame Sequential Cathode Ray Tube Project

Postby Harry Dalek » Tue Aug 14, 2018 4:43 pm

FlyMario wrote:I have to look at this deeply sometime. I am fascinated that you are using Decade counters. I am always puzzled by doing that instead of using Binary Counters. I thought maybe you are making a DAC to control the horizontal and vertical position. But seems that binary would be more logical. So I must be way off :)

I hope this will work its looking good and apart from the different line frame rates i have pretty much done this all before same circuits using Steven Anderson's DAC used once again here ....should be a club circuit it works well for me every time .
It more than likely is ! to use binary ic's ....working this out slowly and i am using those to make the timing frequencies for the DAC Ramp and sync the 3 colour switching ....pretty much using what i have in my spare parts collection had a lot of 7490s so on using 4017's i had an amount of them too laying around .
I will draw the framing timing circuits soon .
My main interest in the parts were the frequencies i needed out of the things ,you could more than likely program a PIC these days ? to cut out most of the ic's but i do like the electronics i grew up with .
Do keep an eye out for the small colour CRTs i noticed they are becoming very rare ....off topic ...its funny seeing so many plasmas on the nature strips broken ...in their day you never saw a crt on the side of the road only when the flat screen plasma tv's came out every one started to get rid of their crt tvs...may be because they could be repaired there's no where to take any thing to be fixed today ! looking at them i don't think a plasma tv would be fun to scrap as well surface mounted parts double sided circuit boards..... the invention of a devil :evil:
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Re: Frame Sequential Cathode Ray Tube Project

Postby FlyMario » Tue Aug 14, 2018 9:32 pm

hehe I bought a "Windsor Deluxe Portable T.V. AM/FM radio model VR-99" off of Ebay $16.00 to my door. I figured it might be fine as a first attempt at a tubed NBTV with all the stuff to drive the tube. I do want to make my round russian tubed one look so very nice so best to work out all the problems on something I don't care that much about.
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Re: Frame Sequential Cathode Ray Tube Project

Postby Harry Dalek » Tue Aug 14, 2018 10:55 pm

FlyMario wrote:hehe I bought a "Windsor Deluxe Portable T.V. AM/FM radio model VR-99" off of Ebay $16.00 to my door. I figured it might be fine as a first attempt at a tubed NBTV with all the stuff to drive the tube. I do want to make my round russian tubed one look so very nice so best to work out all the problems on something I don't care that much about.


Yes the small B/w ones are still about ,some of the differences in the tubes the magnetic tube is harder to master on the deflection side but it can do higher line rates as in finer raster dot its easier to focus .
The electrostatic tube is easier to deflect but voltages can be higher for this and the higher voltages are all at the tube socket where as its mainly at the Anode for the magnetic so they both have there good and bad points .
Yes you have to learn some where i suppose i was interested in bother types .
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Re: Frame Sequential Cathode Ray Tube Project

Postby Harry Dalek » Wed Aug 15, 2018 7:27 pm

Here's more on the framing circuit inputs pretty much frequencies F input of the 7490s shown then in out of the ic above the other .
The 1.84320MHZ crystal oscillator frequency pin 9 4060 into ic13 pin 14 4017 hooked up to a 6 count reset pin 5 to 13 then pin 1 of ic13 into ic14 pin14 then pin 1 into above 7490 F input so on /
I wanted to get this down memory fades Quick :roll:
Again using one half of Steve Anderson's DAC
Attachments
FFFframeFSCtv (1).jpg
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Re: Frame Sequential Cathode Ray Tube Project

Postby Harry Dalek » Thu Aug 16, 2018 8:11 pm

All the line frame frequencies hooked up to the DAC and i am Glad to see the correct line and frame rates to the DAC ...getting there
Line frequencies shown , 15line 450 hz 32 line 1.2khz 120 line 3.6khz
click on photo to enlarge
DAC.jpg



I am going to look at detecting the line sync pulse from the 120 line and 32 line FSC video ...the 15 line has none so crystal has to do the work here ..i hope .
Attachments
DSCN6242_x264.mp4
(6.36 MiB) Downloaded 473 times
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Re: Frame Sequential Cathode Ray Tube Project

Postby FlyMario » Tue Aug 21, 2018 11:44 pm

So, I am thinking about this when I should be working.

Let's say I have a tube and I need to generate 32 lines. I have tons of ttl logic chips. So say I have 4 bit counters which should be able to give me my 32 lines. I hook resistors to the outputs from the pins to make 2 DACs. One for the + direction of the electron beam and one for the - direction of the electron beam. I suspect I would need to go into an OPAMP to increase the output voltage. But how then do I get negative voltage? Do I make a voltage divider in the negative range and have the dacs fight against that voltage?

I take it that you can't get - voltage from a dc circuit. Do I need an ac transformer, like two half rectifiers and two huge capacitors to even get both sides. Seems I would need +12v gnd -12v right? the 12v part doesn't matter.

See welcoming me to this board was a bad idea :)
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Re: Frame Sequential Cathode Ray Tube Project

Postby Harry Dalek » Wed Aug 22, 2018 8:29 pm

FlyMario wrote:So, I am thinking about this when I should be working.


BTW i know we use our forum names but are you a Mario ? i like to know first names if possible :wink:

Sorry but do you mean when will this be an operational FSC CRT TV ,i am working on it...i am working on the sync seperator for the line sync slicing part at the moment and when i have time ...its the birthday season for my family all in a row so little time of late ...any way i am not really happy with the 3.6 khz line sync pulse result its there but the sync amplitude is wavy video must be effecting it ...the other problem is the FSC 32 line should be at 1.2 khz i am seeing normal 400hz both looking on a audio spectrum analyzer there are harmonics on the 32 line its 400 800 1.2 and so on the sync seperator is picking 400hz bit of head scratching i know why its showing its the main frequency so i might be missing something ...it has got me a touch confused as its not the cased for 120 line 3,6 khz is correct ...The 15 line has no sync at all so i can't check any thing here .
But whats left to do really is i want to sync it to the sync line sync pulse i need to mount the deflection amplifier power transistors a video amplifiers and hook the power supply voltages for the CRT .
I don't have a time line for doing this just as things work out on to the next step till its done .

Let's say I have a tube and I need to generate 32 lines.


A CRT Yep

I have tons of ttl logic chips.


Good to make use of them ...old parts need love as well :mrgreen:


So say I have 4 bit counters which should be able to give me my 32 lines.


If you are going down this road ...I would use a crystal oscillator as a starting point and Steve Anderson's idea to use of the 3.2768 mhz to a 4040 if you use some thing else as i had to with this one and what i had handy get that calculator out !

I hook resistors to the outputs from the pins to make 2 DACs.


I went down this road when Klass and Steve mentioned doing all this in a DAC way ,i didn't have 1 % resistors so my first result was a bit primitive and all the wiring a DAC chip was the way to go here ,but if you can do it go for it that side i rather cut out all the resistors .

One for the + direction of the electron beam and one for the - direction of the electron beam. I suspect I would need to go into an OPAMP to increase the output voltage. But how then do I get negative voltage? Do I make a voltage divider in the negative range and have the dacs fight against that voltage?


As is the thing is fine for a tv oscilloscope but for the deflection amplifier need a buffer amplifier to connect to the deflection amplifier or it effects the wave form if you don't use it ...but i am now thinking of my magnetic deflection as here on the project and the last tv .

I take it that you can't get - voltage from a dc circuit. Do I need an ac transformer, like two half rectifiers and two huge capacitors to even get both sides. Seems I would need +12v gnd -12v right? the 12v part doesn't matter.


i use a few smaller transformers for the low and high voltages hard to work out what you need till we know which CRT your going to use .

Might be best to make a scope tv as a stepping stone to the crt one you can pretty much use the circuits later on the CRT build .
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Re: Frame Sequential Cathode Ray Tube Project

Postby FlyMario » Thu Aug 23, 2018 2:07 am

no, my first name is Fly :)

Pete
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Re: Frame Sequential Cathode Ray Tube Project

Postby smeezekitty » Thu Aug 23, 2018 7:37 am

I went down this road when Klass and Steve mentioned doing all this in a DAC way ,i didn't have 1 % resistors so my first result was a bit primitive and all the wiring a DAC chip was the way to go here ,but if you can do it go for it that side i rather cut out all the resistors .


If you have a trimmer resistor for each output bit, I am sure an R2R ladder DAC could actually yield quite a good result with a little tuning
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Re: Frame Sequential Cathode Ray Tube Project

Postby Harry Dalek » Thu Aug 23, 2018 7:32 pm

smeezekitty wrote:
If you have a trimmer resistor for each output bit, I am sure an R2R ladder DAC could actually yield quite a good result with a little tuning


Yes that's a way to do it ,it would sure work apart from the extra size of the trimmers ,using what Pete has i can understand wanting to use whats in your parts box.
The Tesla DAC chips i use i got a batch of 20 something so that's what i have handy i am happy not having to worry about that resistor part :wink:

Here's my bad go at it !
viewtopic.php?f=31&t=2412&start=30
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Re: Frame Sequential Cathode Ray Tube Project

Postby Harry Dalek » Sun Aug 26, 2018 9:16 pm

Ok had a bit of time today to test the sync slicing from Steve's reworking of Klass's circuit .
NBTV Sybc Sep Initial 3.gif
n
NBTV Sybc Sep Initial 3.gif (11.28 KiB) Viewed 7746 times

I used it on the 32 line Anderson monitor and the A for Andrew monitor where i dabbled in 48 and 64 line 120 line .
viewtopic.php?f=31&t=2391
Tested this first today on first the B/w 32 line reversing wav i see this worked fine again ,
Reversing Bars 1.wav
(5.49 MiB) Downloaded 352 times

Screen 00046.jpg

400hz.jpg
400hz.jpg (115.56 KiB) Viewed 7746 times

Pretty much same result on 32 line FSC which i would of expected 1200 hz for the line rate but showing up 400hz Garys software says its 400hz i was thinking the line rate should be 3 times this 1200hz but it does play on a 32 line 400hz viewer software...the Audio spectrum analyzer shows the 400 hz sync is correct.
Screen 00062.jpg

Number of frames per second: 12½
Number of lines per frame: 32
Number of lines per second: 400
Line scanning direction: vertical, bottom to top
Frame scanning direction: horizontal, right to left
Viewing position on disc: right
Rotation direction of disc: anti-clockwise
Picture orientation: portrait
Picture aspect ratio: 3 : 2
White level: 1V
Black level: 0V
Sync tip level: -0.42V
Line sync: ~7% of line length
Frame sync: Missing pulse between line 32 and line 1
Output sample rate: 48000

32linebirdsfsc.wav
(4.69 MiB) Downloaded 349 times

Screen 00060.jpg

120 line is what i would expect line rate 3.6khz
Screen 00063.jpg

3.6khz.JPG
3.6khz.JPG (378.21 KiB) Viewed 7746 times

So here the sync slice still works but on the 4538 mono its not working so timing capacitor must be off it understandable a fair few line rates above what it was made for ..i recall going to the start of this post it was still fine on 48 line and 64 line just and when i was testing 120 line on the A for Andrew monitor not working so same results today at the monostable stage .
I am not sure and rather a clean pulse go to syncing the 4040 via this so the 120 line is still a problem so far .
The 32 line FSC i am confused about the line rate i was thinking it should be times 3 the B/w rate .... :roll:
Attachments
birds_x264.mp4
(945.73 KiB) Downloaded 452 times
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Re: Frame Sequential Cathode Ray Tube Project

Postby FlyMario » Sun Aug 26, 2018 11:30 pm

Woah that Steve / Klass circuit is very very interesting. What in the world is that vr601 symbol?

I should build this circuit for my Russian CRT TV.

Poor birds.

On your TV are you going for 12.5fps Harry?

Pete
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Re: Frame Sequential Cathode Ray Tube Project

Postby Steve Anderson » Mon Aug 27, 2018 4:25 pm

VR601 is a trimmer pot, same idea as a front-panel control (e.g. volume in a radio) but mounted on the board for a once-off adjustment (set-and-forget). VR = Variable Resistor.

There are still differences between symbols in circuits, even with the advent of ISO standard symbols which have been around for decades. I'm not saying I follow the ISO standards 100%, but I don't use the zig-zag line for a resistor, but you'll still find them on many circuits coming out of the US. Some schematic drawing programs also still use them, but often they'll let you choose the rectangle instead of the zig-zag.

Steve A.

You'll also notice that many IC datasheets coming out of the US are dual-dimensioned, both imperial and metric units are drawn the on 'physical' (dimentional) pages (usually the last one(s)). Simply because the rest of the world has no clue what an inch, gallon or mile is. Throw in the confusion between a US gallon and an imperial one...
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