48 line 64 line Conversion

Moderators: Andrew Davie, Steve Anderson, Dave Moll

48 line 64 line Conversion

Postby Harry Dalek » Tue Jun 13, 2017 6:27 pm

This will be a good place to start for the Conversion work .
I had forgotten i did try to make the sawtooth oscillators variable i tried it on a early circuit idea SSTV by changing R704 and R724 to trimmers and the capacitors C702 and C721
well i didn't draw up the changes so from memory only any case i am not sure the sawtooth oscillators are the problem
I have not had time to work more on this just think about it
Results were monitor at 32 line unchanged the sawtooth line frequency synced from a 64 line video ..sawtooth 800 hz and the frame drops back to 6 hz results 2 images slow rolling .
i was thinking at first it was a sawtooth circuit frequency change needed but since we are deriving the framing from the line i am starting to think its the timing of the monos that is the problem .
Do you think the same Steve ?
Attachments
3BP1 NBTV Sawtooth 3.gif
3BP1 NBTV Sawtooth 3.gif (15.34 KiB) Viewed 135 times
IMG_2599.JPG
IMG_2599.JPG (234.09 KiB) Viewed 135 times
IMG_2606.JPG
IMG_2606.JPG (220.74 KiB) Viewed 135 times
IMG_2692.JPG
IMG_2692.JPG (226.6 KiB) Viewed 135 times
circuits.jpg
circuits.jpg (290.11 KiB) Viewed 134 times
Last edited by Harry Dalek on Thu Jun 15, 2017 2:26 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.
User avatar
Harry Dalek
"Fester! Don't do that to 'Thing'"
 
Posts: 3229
Joined: Fri Sep 26, 2008 4:58 pm
Location: Australia

Re: 60 line Conversion

Postby Harry Dalek » Wed Jun 14, 2017 10:49 pm

I looked into what results 48 line 60 and 120 into the monitor as far as whats showing up at the saw tooth oscillators and any video results if possible ...
vertical scan 48 line saw tooth showing 587 hz frame 6hz image slow horizontal roll
horizontal scan 60 line 249hz 6hz No image at all
vertical scan 64 line 800hz 6hz image slow horizontal roll
horizontal scan 120 line 249hz 6hz no image at all
I was using Doms software for the 48 and 64 line which works ...........vertical scanning
Using Garys software the monitor out displays nothing on 60 line or 120........ horizontal scanning
i am not sure what wrong here the line frequency is way off as well .
The wav files with NBTVA are made via Doms software and vertical scan all rest are via Garys software horizontal scan .
BTW Hint i don't think Gary has a 60 line or 48 line viewer but Doms you can view the 48 line and view Garys 60 via TEKADE 60 lines
Tweety Bird Youtube is 48 line playing on the monitor as is

youtu.be/oMcZ_fExb6s

EDIT the 249 hz is no video no sync detection .....using Garys video its on a stereo channel the one i was not using here so swapping channels or tuning the video into a mono wav file fixes this problem .
Attachments
Screen 00004.jpg
Screen 00004.jpg (54.73 KiB) Viewed 121 times
IMG_2716.JPG
IMG_2716.JPG (211.24 KiB) Viewed 121 times
IMG_2713.JPG
BBC eye 48 line
IMG_2713.JPG (113.53 KiB) Viewed 121 times
IMG_2714.JPG
BBC eye 64 line
IMG_2714.JPG (110.96 KiB) Viewed 121 times
IMG_2740.JPG
48 line roll 2 images
IMG_2740.JPG (139.01 KiB) Viewed 121 times
60linebatman-says-no.wav
(5.89 MiB) Downloaded 1 time
Tbird48line-48000-NBTVA48-p-II.wav
(860.88 KiB) Downloaded 1 time
Tbird64line-48000-NBTVA64-p-II.wav
(696.72 KiB) Downloaded 1 time
120line3batman-says-no.wav
(5.05 MiB) Downloaded 1 time
Last edited by Harry Dalek on Mon Jun 19, 2017 5:09 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.
User avatar
Harry Dalek
"Fester! Don't do that to 'Thing'"
 
Posts: 3229
Joined: Fri Sep 26, 2008 4:58 pm
Location: Australia

Re: 48 line 64 line Conversion

Postby Harry Dalek » Thu Jun 15, 2017 2:59 pm

I have changed the tile here from 60 line to 48 and 64 line as this is the result from today ...
It looks like it so far is a minor change to the circuit R704 i at the moment have a 1meg trimmer across it which i adjust from 6 hz on the frame sawtooth frequency to get 12 hz on the on this sawtooth and it even syncs as well...
48 line test below next post i will show the 64 line results so far
Very good Design Steve ,i think i could push this to 120 line but at the moment i am having problems with viewing Garys wav files 60 line and such which i am puzzled about as it may be in horizontal scan but thats a thing to change on the deflection plates for correct scan not a video its self problem .

youtu.be/sULCAq6Q7UA

youtu.be/ahOVF-xgvNQ
Attachments
IMG_2747.JPG
IMG_2747.JPG (158.68 KiB) Viewed 109 times
Last edited by Harry Dalek on Thu Jun 15, 2017 7:57 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.
User avatar
Harry Dalek
"Fester! Don't do that to 'Thing'"
 
Posts: 3229
Joined: Fri Sep 26, 2008 4:58 pm
Location: Australia

Re: 48 line 64 line Conversion

Postby Steve Anderson » Thu Jun 15, 2017 3:34 pm

Well, I think that you need to be sure of all the line and frame rates for these various standards, one way is to examine the files in Audicity, this will also allow you to check how the frame sync is done, it may not always be the 'missing sync' method.

If they all use the 'missing sync' method the it should be a case of changing some components in the ramp/sawtooth generators. Both line and frame if they use different frame rates as well. I'm sorry but I haven't had the time to go look at the circuits. I'm in Vietnam until Saturday evening.

Steve A.
User avatar
Steve Anderson
"Fester! Don't do that to 'Thing'"
 
Posts: 3502
Joined: Fri Mar 30, 2007 10:54 pm
Location: Bangkok, Thailand.

Re: 48 line 64 line Conversion

Postby Harry Dalek » Thu Jun 15, 2017 3:42 pm

The slight problem with 64 line at the moment is the deflections are cut back a touch by some 10k resistors which limit my screen size for this format its also a little more touchy syncing .
Very happy it pretty much can do 3 systems now

youtu.be/UOR-IyNAUXw

youtu.be/NdvYMghSxpE
Attachments
IMG_2803.JPG
IMG_2803.JPG (141.17 KiB) Viewed 108 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.
User avatar
Harry Dalek
"Fester! Don't do that to 'Thing'"
 
Posts: 3229
Joined: Fri Sep 26, 2008 4:58 pm
Location: Australia

Re: 48 line 64 line Conversion

Postby Harry Dalek » Sun Jun 18, 2017 10:53 pm

Been away for a trip back today ...any case gave me some time to look at Garys wav files made by video2nbtv v3 alpha and Doms ScrapeNBSC finding out doms makes a mono wav file and Garys one side of a stereo channel helped .
So got Garys software wav file to work on the monitor up to 60 line today but only on a higher audio level 120 not yet .
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.
User avatar
Harry Dalek
"Fester! Don't do that to 'Thing'"
 
Posts: 3229
Joined: Fri Sep 26, 2008 4:58 pm
Location: Australia

Re: 48 line 64 line Conversion

Postby Harry Dalek » Tue Jun 20, 2017 8:07 pm

Had a little time to look at the problems ,it works spot on for 32 line but the blanking does not seem to be working seeing the fly back is viewable at 48 and 64 line but i see the pulse that switches the 4066 is there which i think is used for blanking some times worse than others as you see on the 48 line top picture to the other 2 64 line pic's/
Looks like it was an old school problem :wink:
https://antiqueradio.org/Admiral24A12Television.htm
Photos not great but i was testing test cards this afternoon i also still need to adjust the line sawtooth to its deflection amp so i can increase screen size for 64 line ..i will more than likely ad a switch with another resistor to parallel the 10k in circuit that will drop its resistance and increase the sawtooth a touch to the deflection amp.
Attachments
IMG_2891.JPG
IMG_2891.JPG (254.78 KiB) Viewed 79 times
IMG_2827.JPG
IMG_2827.JPG (241.73 KiB) Viewed 79 times
IMG_2844.JPG
IMG_2844.JPG (243.34 KiB) Viewed 79 times
Vertical_Blanking.jpg
Vertical_Blanking.jpg (150.54 KiB) Viewed 76 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.
User avatar
Harry Dalek
"Fester! Don't do that to 'Thing'"
 
Posts: 3229
Joined: Fri Sep 26, 2008 4:58 pm
Location: Australia

Re: 48 line 64 line Conversion

Postby Steve Anderson » Wed Jun 21, 2017 2:18 pm

The frame retrace is visible as there is no sync pulse like for the line situation, this can be fixed but I need to look into it. I'll assume you're using the circuits posted above - with the correction mentioned a while back (my fault).

It's possible you may have the black level set a bit too high, this is easy to do on test-cards, especially if they're black/white with no greys. In broadcasting there's a test signal called PLUGE which is for the sole purpose of setting the monitor black level accurately though it still uses the MkI eyeball to do so. Below is one example, they varied between equipment manufactures but basically they're the same idea.

Steve A.
Attachments
PLUGE 1.jpg
PLUGE 1.jpg (15.76 KiB) Viewed 70 times
User avatar
Steve Anderson
"Fester! Don't do that to 'Thing'"
 
Posts: 3502
Joined: Fri Mar 30, 2007 10:54 pm
Location: Bangkok, Thailand.

Re: 48 line 64 line Conversion

Postby Harry Dalek » Wed Jun 21, 2017 5:24 pm

Steve Anderson wrote:The frame retrace is visible as there is no sync pulse like for the line situation, this can be fixed but I need to look into it. I'll assume you're using the circuits posted above - with the correction mentioned a while back (my fault).

OH i went looking to see the difference from 32 line to 48 64 ,i was thinking the timing might be off controlling the 4066 also the framing is a bit tight gets harder from 48 to 64 line but i see the pulse is there still at pin 5 6D test point of the 4066....no not your fault me fiddling at other line rates wondering why is it so .
The monitor works as it should at 32 line i would say perfect ,i will keep the 32 line option Steve but yes circuits are as in the schematics posts and any changes i have mentioned there.
Changes for 48 and 64 line are at the moment are only temporary for now R704 just has a pot across more than likely not the best choice 1m pot but it was handy might just need a fixed resistor and a switch it across R704 to get 12 hz on the frame sawtooth .
What i do is connect a frequency meter on the frame sawtooth and i adjust the line pot over R704 and watch the result on the meter for the frame saw tooth and adjust to 12 hz there .
Funny enough i have not looked at the result of this change on the line sawtooth frequency i am adjusting it must be doubling it .
without the frequency change to line sawtooth the frame sawtooth is 6hz for both 48 and 64 line .
For 64 line the size control at the moment is set to maximum fine for 48 line bit small for 64 line ....the framing size control still has some adjustment to it so i don't think i need to adjust change that 10k R708.

t's possible you may have the black level set a bit too high, this is easy to do on test-cards, especially if they're black/white with no greys. In broadcasting there's a test signal called PLUGE which is for the sole purpose of setting the monitor black level accurately though it still uses the MkI eyeball to do so. Below is one example, they varied between equipment manufactures but basically they're the same idea.

Steve A.


Yes perhaps i can see some adjustments to other tests its not to bad ...not a big problem i was wondering if i was doing some thing wrong here .
I will make a video file from that test card you posted up and try it .. :idea:
Something else trying Garys 60 line it does not work to well i get a picture but its a bit distorted has a bright strip to one side of it and does not sync well ..i can only think this has to be something to do with the timing number of lines Doms 64line vertical format which works fine double 32 lines ...does not explain why 48 line also works very well ....Garys wav video files are in horizontal line format ...Doms vertical mono 48000 bit i have to look again but Garys comes out left hand stereo channel and 96000 checking with audacity...not sure if this is a problem for a analog monitor like this .
Gary also has a 120 line frame sequential colour in hes Video2NBTV-V3 Alpha as with 60 line 120 here is worse showing up nothing might be pushing my luck here with that one on the monitor .
I might post some gray bar video files up .

Just been cleaning up the wiring seeing how the boards fit in the case ,and starting to work out front panel controls ....some i know whats needed the other line rates will need some switching .
Attachments
IMG_2905.JPG
IMG_2905.JPG (363.03 KiB) Viewed 65 times
IMG_2898.JPG
IMG_2898.JPG (321.98 KiB) Viewed 65 times
IMG_2897.JPG
IMG_2897.JPG (352.91 KiB) Viewed 65 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.
User avatar
Harry Dalek
"Fester! Don't do that to 'Thing'"
 
Posts: 3229
Joined: Fri Sep 26, 2008 4:58 pm
Location: Australia

Re: 48 line 64 line Conversion

Postby Harry Dalek » Wed Jun 21, 2017 7:19 pm

I made a gray bar video a few video formats via Dom and Garys software ..the 60 line baird one has a whitesh bar to one side stuffed up there thats why it looks different ..
Garys files come out very large the 120 line i had to beat a second to make it small .

What i have tried on the monitor is Doms 48 line and 64 line that works
Garys 60 line party works
Garys 120 line nothing comes up viewable.
other systems i have not tried yet .
Attachments
60linegary.wav
(14.65 MiB) Downloaded 1 time
120linegary.wav
(225.06 KiB) Not downloaded yet
Dom48line-48000-NBTVA48-w-II.wav
(366.4 KiB) Downloaded 2 times
Dom60lineBaird-48000-Baird60-w-II.wav
(426.46 KiB) Downloaded 1 time
Dom60Tekade-48000-Tekade60-w-II.wav
(418.45 KiB) Downloaded 1 time
Dom64line-48000-NBTVA64-w-II.wav
(262.3 KiB) Not downloaded yet
images.gif
images.gif (4.88 KiB) Viewed 61 times
48lineDom.jpg
48lineDom.jpg (72.72 KiB) Viewed 61 times
60inegary 00000.jpg
60inegary 00000.jpg (62.46 KiB) Viewed 61 times
60linedomBaird.jpg
60linedomBaird.jpg (66.22 KiB) Viewed 61 times
60lineDomTekade.jpg
60lineDomTekade.jpg (64.67 KiB) Viewed 61 times
64lineDom.jpg
64lineDom.jpg (64.85 KiB) Viewed 61 times
120linegary.jpg
120linegary.jpg (55.01 KiB) Viewed 61 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.
User avatar
Harry Dalek
"Fester! Don't do that to 'Thing'"
 
Posts: 3229
Joined: Fri Sep 26, 2008 4:58 pm
Location: Australia

Re: 48 line 64 line Conversion

Postby Steve Anderson » Wed Jun 21, 2017 7:42 pm

OK, having refreshed my mind as to how I did this, you're correct in adjusting R705 and R725 for the different frame and line rates. The question is, what are the line and frame rates? I'm not clear on this. Given that data I can probably point you in the right direction. I need all the various standards you're hoping this to work on, it will, but I need the numbers.

e.g. Standard NBTVA 12.5Hz Frame, 400Hz Line, 32 lines per frame.

...and so on....

Do they all use the 'missing pulse' frame-sync system?

Steve A.
User avatar
Steve Anderson
"Fester! Don't do that to 'Thing'"
 
Posts: 3502
Joined: Fri Mar 30, 2007 10:54 pm
Location: Bangkok, Thailand.

Re: 48 line 64 line Conversion

Postby Harry Dalek » Wed Jun 21, 2017 8:44 pm

Steve Anderson wrote:OK, having refreshed my mind as to how I did this, you're correct in adjusting R705 and R725 for the different frame and line rates. The question is, what are the line and frame rates? I'm not clear on this. Given that data I can probably point you in the right direction. I need all the various standards you're hoping this to work on, it will, but I need the numbers.

e.g. Standard NBTVA 12.5Hz Frame, 400Hz Line, 32 lines per frame.

...and so on....

Do they all use the 'missing pulse' frame-sync system?

Steve A.



32 line pretty much as we know 400hz 12.5 no problems
I will double check the others tomorrow and give the results of circuit unchanged and changed ...and with R704...i will look into 705 and 725 i didn't try those.
But yes results were frame frequency changes with the line .
I do know unchanged testing at the sawtooth oscillators 64 line 800hz and 6hz 60 64 and 48 line all give 6hz at the framing all the same .
Results when circuit changed and adjusted for 12 hz framing for all its pretty much the same and even for for 32 line all give 12hz that i was not expecting .
But yes i need to test and post up the numbers.

I am interested in this being multi system 32 48 (60 64 or one of the 2) and 120 mainly because all these i can use software to make the video ..
I know perhaps 120 might not give best results on this monitor but i want a crt monitor to view it if possible .
Now i don't know about Dom's 48 and 64 just says NBTVA standard
Garys a lot more information good Gary !
Number of frames per second: 12½
Number of lines per frame: 60
Number of lines per second: 750
Line scanning direction: horizontal, left to right
Frame scanning direction: vertical, top to bottom
Viewing position on disc: top
Rotation direction of disc: clockwise
Picture orientation: landscape
Picture aspect ratio: 3 : 4
White level: 1V
Black level: 0V
Sync tip level: -0.42V
Line sync: ~7% of line length
Frame sync: Missing pulse between line 60 and line 1
Output sample rate: 96000

120 line frame sequential colour but b/w picture would give same results ?
Number of frames per second: 25
Number of lines per frame: 120
Number of lines per second: 3000
Line scanning direction: horizontal, left to right
Frame scanning direction: vertical, top to bottom
Viewing position on disc: top
Rotation direction of disc: clockwise
Picture orientation: landscape
Picture aspect ratio: 4 : 3
White level: 1V
Black level: 0V
Sync tip level: None
Line sync: None
Frame sync: None
Output sample rate: 576000
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.
User avatar
Harry Dalek
"Fester! Don't do that to 'Thing'"
 
Posts: 3229
Joined: Fri Sep 26, 2008 4:58 pm
Location: Australia

Re: 48 line 64 line Conversion

Postby Steve Anderson » Thu Jun 22, 2017 11:50 am

Harry, I meant R704 and R724, my mistake again! In a rush as ever these days.

Assuming you've got those two resistors right for 400Hz and 12.5Hz it should be possible to work out their value at other rates. Say a 750Hz line rate.

If 400Hz required a resistor of 12k then for 750Hz it should be 400/750*12k = 6k4, try a 6k8 first.

In the other direction where you want to slow things down...say 12.5Hz needed 15k, and you want a frame rate of 6.25Hz, 12.5/6.25*15k = 30k, try 27k or 33k. 30k can be approximated by 33k||330k.

Steve A.
User avatar
Steve Anderson
"Fester! Don't do that to 'Thing'"
 
Posts: 3502
Joined: Fri Mar 30, 2007 10:54 pm
Location: Bangkok, Thailand.

Re: 48 line 64 line Conversion

Postby Harry Dalek » Thu Jun 22, 2017 11:54 am

Steve i have some numbers i hope will be helpful
Ok
The sawtooth oscillators no video free running line 180hz frame 6 hz

Circuit unchanged as is for 32 line operation taking readings with video
32 line 400hz 12 hz
48 line 800hz 6hz
60 line Gary horizontal scanning 750 hz 6 hz
60 line baird and tekade 750 hz 6 hz
64 line 800hz 6hz
120 line .....same as sawtooth oscillators free running no video no sync

With a pot across R704 adjusting frame sawtooth to 12.5 hz or best i can with video .
32 line 400hz 12 hz
48 line 587hz 12hz
60 line gary 750 12hz
60 line baird and tekade 737hz 12hz
64 line 787hz 12hz
120 line same as free running

i would be happy with 32 48 60 or 64 120 ...32 48 and 64 are fine for vertical scanning .
Gary is using a horizontal scanning for the 60 120 which would mean switching of the deflection plate connections or perhaps switch swapping the sawtooth to the deflection amplifiers that might be better.
Making a multi system CRT monitor would be of interest to many ... i suppose doing it in steps might be the way to go i am interested in what you think is possible .
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.
User avatar
Harry Dalek
"Fester! Don't do that to 'Thing'"
 
Posts: 3229
Joined: Fri Sep 26, 2008 4:58 pm
Location: Australia

Re: 48 line 64 line Conversion

Postby Steve Anderson » Thu Jun 22, 2017 12:04 pm

Rather than swap the actual CRT plates, use a DPDT switch to swap the inputs to the deflection amps. it's low-voltage, i.e. safer.

Steve A.
User avatar
Steve Anderson
"Fester! Don't do that to 'Thing'"
 
Posts: 3502
Joined: Fri Mar 30, 2007 10:54 pm
Location: Bangkok, Thailand.

Next

Return to The Tasmanian Devil VCR139....A for Andrew

Who is online

Users browsing this forum: No registered users and 1 guest