I am envious of your electronics knowledge. I wish I had more. I started out learning electronics many, many years ago but ultimately went in a different direction. It is still an area I am very interested in and I will be trying to learn more. Thanks for your interesting videos.
I wish I went in a different direction myself. I always wanted to work in TV production. I actually trained for that career. Electronics was my plan b. TV production didn't work out, went to work on electronics repair and video production became a side line. I did well in video production but could have done much better if I had invested all my time in the production business. Did repair work for a living for 20 years, that was enough for me.
It really is not difficult. You have to have both vertical and horizontal oscillators and output circuitry to generate the sweep drive for the yoke. A simple step up transformer is all that is needed. The current is in the microamp range, so the transformers can be very small for these little tubes.
Yeah, it's annoying when some manufacturers use weird color cables for power, like one that I have where red is ground and yellow is positive. I almost blew it up by accident.
In the absence of the correct original detector, I suppose one could experiment with a photo-diode or photo-transistor and a filter to try and getting it to sync and show colour?
@@aarontrupiano9328 No, The detector was received but not the color filters for it. I don't know what wavelengths they pass. I tried blue and yellow but no joy, it only displays black and white. Still have it. Would like to get it to display color but without the correct filters that isn't going to happen.
What the filters do is detect where the beam is as the beam moves across the screen the filters produce a varying waveform created by the color stripes on the tube. They are required to be in a viewfinder shell so no outside light affects them. Sony did it differently by adding a fourth stripe to the inside of the tube that emits UV light and then put there beam detectors on the bell of the tube looking into the back of the tube that only detect the UV strobe stripe. Sony patented there be index design called indextron. Other companies had to come up with their own way of doing it as to not infringe with Sony's patent and this was their result.
@@12voltvids but i still don’t understand how those sensors detect the light beam unless they use prediction, also how is blue generated since theres only a green and violette sensor,mmmm Also you might think that a single light beam with a color shadown mask or trinitron might be possible by just increasing the speed of the light beam 3 times by alternating between red,green and blue in a row in a certain pattern by moving from one position to the next one and back again, Also you might think that color turquaze and red could be enough to produce all 3 basic colors ,because when no light is hitting turquaze you will get blue but once you shine yellow light against it you will get green , now just imagine cameras and tv sets only relying on turquaze & red to produce all 3 basic colors, maybe not exactly but close .
You're totally missing the point on how the beam index system works. The beam index still uses three colors red green and blue but unlike a conventional picture tube that has three guns each aimed at the respective color dot or stripe which is aligned using a shadow mask or aperture grille a beam index tube has no aperture grille or Shadow mask and uses one gun like a black and white tube therefore the circuitry needs to know where the beam is as it scans the tube surface two ways this has been done number one with Sony's system that was used on both their trinicon camera system and on the indextron CRT. On the trinicon camera tube there was a metal grid laid out across the target with a separate lead that exited the tube as the beam scanned the target this electrode would detect the beam passing over it and produce a pulse that was used by the multiplex circuit to create a phase lock loop to chop up the colors into the red green and blue components as filtered by the stripe filter on the front of the tube. On the indextron tube there was a fourth stripe added to the backside of the phosphorus on the front you would see red green and blue and then a slight space followed by red green and blue that small space had a UV phosphorus stripe that would emit ultraviolet light but it was painted on the backside of the screen so as the beam passed over this UV stripe it would emit a pulse of ultraviolet light this pulse of ultraviolet light was detected by two sensors that were placed on the bell of the tube I would look into the back of the tube this provided the reference signal to synchronize the phase lock loop to multiplex the three colors into a single switched output so the switched output goes red green blue red green blue red green blue as the beam passes over the tube this is Sony's patented design. Other companies like Hitachi had to come up with their own method of synchronizing the switching for the color circuit they did it by using a yellow and cyan filter in front of photo transistors. The yellow filter would pass light from both the red and the green stripes and the cyan filter would pass light from both the green and the blue stripes if you're following me now you would see that as the beam were to pass over the red and then the green stripe there would be a pulse presented to the yellow photo transistor and then as the beam continued from the green to the blue the second pulse would start as it was passing over the green and continue into the Blue then switch back to the yellow sensor as the beam hit the next red stripe now you have an overlap you have a pulse of light that is only present when the beam is over the red stripe and you have a pulse of light that is only present when the beam is over the blue stripe and you have a wider pulse of light from both detectors at the same time when the beam is over the green so you get basically an overlap so that there's signal through both photo transistors when the beam is over the green but only a single when the beam is over the red and the blue thereby the multiplex circuit knows this is a red and this is a blue and this is a green and it can time the multiplex switch accordingly it's a simple system much simpler than Sony's which required that fourth stripe on the tube the downside is that the photo detectors with their cyan and yellow lenses must be totally shielded from any external light so the only application is building them into the viewfinder where they are far enough back and in behind magnifying lenses and so forth to prevent any external light from reflecting into the sensors which would cause them to lose sink and the picture to turn to black and white.
I understand how it would detect the scan frequency and phase with a PLL by detecting pulses from the red phosphor. But I don't get how this works if you have your camera pointing at, say, something green for a while. If the red phosphor doesn't light up at all, the PLL is not going to get any input and the color generator is going to drift, isn't it? In other words, doesn't the detector have sensors for all three colors so that it only loses color sync when it shows a black picture?
There are 2 detectors with color filters over the phjto detector. One detects blue and the other one red/green spectrum. This way there are always 2 signals out of phase with each other. There is also a uv stripe that is picked up with the blue sensor and the tubes are biased so there is always a dim glow so even if the picture is black there is enough emission to operate the pll. Once I get the sensor I will be doing a follow up and will show the quality of these little tubes.
In the CRT the actual place the beams cross over is as they pass through the shadow mask on every drawing I have seen. There are magnets and correction coils on the bell of the tube to dynamically correct the beam as it travels across the screen.
You say the high voltage is 5kV because of color, but I guess its not going to be higher than a comparable b&w since it does not have a shadow mask which absorbs most of that extra energy.
Beam index tubes are nothing more than black and white tubes with color stripe phosphor. It's not so much the shadow mask that absorbs high voltage. In fact it is charged to the same high voltage. It is the fact that you have 3 beams being emitted so 3x the electrons plus you need to accelerate them faster to get them through the shadow mask as a high percentage are going to hit the mask and be absorbed by it.
Do you know what would be cool if you took a bunch of those small one inch half-inch CRTs put them in an array and get one of those control box that used to run those multi CRT displays that you would see in malls to get one big picture out of a bunch of small CRTs
I would imagine if they were using such a device today, a single chip would have been doing all the colour magic, the pcb would be limited by the size of the lopt.
If it was high volume they probably would have but the color crt viewfinder was a commercial failure because if the poor resolution. Cameras with color viewfinder were restricted to auto focus operation because the color viewfinder (tube and lcd) were not good enough for precise focusing. That is why most cameras used bw tubes.
I had never thought about the focus problem, i can see how poor the user feeback would be with colour. I watched a black&white tv for years, an old pye rambler portable with a philips tube, it served me well.:-D A very sharp little picture, i also used it to check the head switching point near the very bottom of the screen scan for vcr checks. People play with the head guides and control head for some reason??. i sat there and got the path correct then small tweaks to get the tracking and sound sync right, plus head signal balance and control head amplitude. I wasted a lot of time helping silly people, but i saved a lot of nice machines from the bin.
@@zx8401ztv In the TV station I worked there was this ancient conrac under scan (black borders on all 4 sides) monitor with about a 19" tube with an 18" picture. It sat atop the old rca tk20 telecine camera. It had no cover on it, just a bare tube clamped into a metal chassis. The tube was a very long tube and the neck was probably 2" in diameter at the gun. It was solid state, but an early one. It ran 24/7 and for most of the day just had a black raster. If you turned out the lights in the control room you could see the raster. The filament in the back glowing orange. This was used on the telecine when we ran either a slide or were running film. Used by the operator for setup. We would put a chip chart or registration chart up and run a slide projector with no slide so it was a white screen that shone through the test chart which were made out of glass and placed on the lens. The we would use this very high resolution monitor to calibrate the 4 tube camera. This old rca camera had 4 pickup tubes. Red green and blue vidcon tubes for the color portion of the image and a larger monochrome tube, an image orthicon if I remember correctly. It had an amazing, razor sharp picture. You could almost feel the xrays blasting through your body standing in front of that bad boy.
lol free xray at work :-D I did have a look for the tk20, i stumbled across a tv video camera museum. The rca section: www.tvcameramuseum.org/rca/rca_list.htm im sure you have been there.
What size would this be considered? I know the smallest traditional CRT with shadowmask is the 1.5" CT-101. Just curious what the smallest beam index color CRT measures in at. Great video btw, just discovered your channel!
This one is 1.25" and so far I only have it working in B/W because I do not have the color filters that go over the 2 detector diodes that sync the color.
@@speedyink Yes, they need to be operated as a viewfinder. Had the fella that donated this one sent it to me as the entire view finder rather than scrapping the cabinet then it would probably be working now. The detectors were mounted in front of the mirror that you viewed the screen through and picked up the beam as it flashed across the screen. One was a yellow filter and the other a blue so by averaging they could figure out where the beam was. A goofy way of doing it like the color vidicon tube (and newvicon, saticon ect in cameras) They used a cyan and green stripe filter as well as clear, and used the relationship to figure out color. Sony did things differently with their trinicon tube, they put a very fine set of vertical electrodes on the surface of the tube that as the beam scanned a voltage would be detected to synchronize the color multiplex circuit, and used a RGB color stripe on the tube. Sony's beam index was called Indextron, because they used a 4th stripe on the inside of the CRT between the red and blue stripes on the front of the tube. This 4th stripe was UV, so it was invisible, but it strobed into the inside of the tube (as it was placed on the back side of the phosphor on the face plate of the tube.) These UV stripes would flash as the beam swept over them, and was detected by a photo detector glued onto a clear section of glass on the bell of the tube. This provided the synchronization signals for the color multiplexing circuit. I have an indextron video projector and it is quite cool. Not a super high resolution picture, but as a single tube projector it is usable and quite bright for a CRT. It is liquid cooled. 7" tube.
@@12voltvids Oh, so if I were to procure a full camera/viewfinder, I could still get it to work! I'm looking at cameras like the RCA CKC-021. I know they use a mirror to point the image to your eye, but it's sounding like I'll need to be careful, and figure out that sensor setup. Good info for sure. My idea was to make a little miniature television cabinet for it. Wow, thanks for the info! Would the Sony KV-4000 use the indextron beam style? That was another set I had my eyes on. I love this sorta technology, so fascinating.
@@speedyink the kv4000 was a Trinitron. The smallest they made. The indextron was the kvx370 which was a 3.7" 3.5 viewable screen. The indextron sets say indextron right next to the red green and blue ovals in the top left side of the cabinet.
Have you seen post #22 on this page: www.vintage-radio.net/forum/showthread.php?t=62138&page=2 Although I think its an RCA manual, the poster says it describes the Hitachi beam indexing viewfinder...
I have schematics for this viewfinder. Change the last digit 1, 2, 3, and 4 to get all four files. www.labguysworld.com/SCH_RCA_EVF-32_BEAM_INDEX_COLOR_CRT_001.pdf For everyone. Enjoy! This viewfinder most definitely has UV index stripes. The photosensor board had two photocells. One is masked in yellow to block UV and pick up white light, the other is masked in deep blue to pick up the UV index pulse. By clever addition and subtraction of the two photocell signals, the beam index pulse could be recovered very clearly.
I have never worked on this type before I know the detector had 2 photo detectors, didn't know if it used a UV stripe or just keyed off the red and blue. Sony did it different using the detector mounted on the bell of the tube, and having the UV stripes on the back side of the phosphorous
Man i love your vids but again 6 ads during the course of one vid just kills the continuity and really spoils the content, thats why i stopped watching tv. Thanks for sharing.
Unfortunately I have no control over the advertising. That is google that places them, and THAT IS HOW I GET PAID. So for those thinking of blocking ads, that reduces my ad revenue, and when my ad revenue goes down I start releasing content only on patreon. Of I could choose to go youtube red, where you have to pay to see. I would rather remain free and ad supported. When you watch TV the advertising pays for the programming just as it does here. When you subscribe to premium services such as HBO you get no advertising as you are paying for the content you consume. If you use one of those black market boxes to steal content, then you are a theif and I regard you the same way as I regard people that use ad blockers to watch my content. The solution I have to that it to make my content paid only, or patreon only content. I have some patreon only content now and would rather not go down that road, and won't as long as the ad revenue continues. I hope you understand how this works. As a content producer I deserve to be paid for my time. I am sure you get paid to do your job, and if your boss asked you to come into work and work for free you would probably tell him where to go, and how to get there.
Thanks for the tutorial at beginning of video. Your electronics videos are always well done.
You're videos are always interesting.
I am envious of your electronics knowledge. I wish I had more. I started out learning electronics many, many years ago but ultimately went in a different direction. It is still an area I am very interested in and I will be trying to learn more. Thanks for your interesting videos.
I wish I went in a different direction myself. I always wanted to work in TV production. I actually trained for that career. Electronics was my plan b. TV production didn't work out, went to work on electronics repair and video production became a side line. I did well in video production but could have done much better if I had invested all my time in the production business. Did repair work for a living for 20 years, that was enough for me.
It's always amazing how they can get a CRT enough voltage to run on a battery. I am used to big-ass CRTs and heavy flyback transformers.
It really is not difficult. You have to have both vertical and horizontal oscillators and output circuitry to generate the sweep drive for the yoke. A simple step up transformer is all that is needed. The current is in the microamp range, so the transformers can be very small for these little tubes.
Yeah, it's annoying when some manufacturers use weird color cables for power, like one that I have where red is ground and yellow is positive.
I almost blew it up by accident.
In the absence of the correct original detector, I suppose one could experiment with a photo-diode or photo-transistor and a filter to try and getting it to sync and show colour?
Original color sync detector has been located and is being sent over. A follow up video once it arrives.
Yay
@@12voltvids was a video on it ever posted? if there was i can't find it.
@@aarontrupiano9328
No, The detector was received but not the color filters for it. I don't know what wavelengths they pass. I tried blue and yellow but no joy, it only displays black and white. Still have it. Would like to get it to display color but without the correct filters that isn't going to happen.
I guess beam index only works with near perfect horizontal linearity, provided by the long bell (looks like a lot less than even 70°?)
Check out the large beam index in my Sony vidimagic projector video.
I don’t know how those filter sensors do work but i would be not suprised if they do serve as color holograms to get color on a b&w tube,
What the filters do is detect where the beam is as the beam moves across the screen the filters produce a varying waveform created by the color stripes on the tube. They are required to be in a viewfinder shell so no outside light affects them. Sony did it differently by adding a fourth stripe to the inside of the tube that emits UV light and then put there beam detectors on the bell of the tube looking into the back of the tube that only detect the UV strobe stripe. Sony patented there be index design called indextron. Other companies had to come up with their own way of doing it as to not infringe with Sony's patent and this was their result.
@@12voltvids but i still don’t understand how those sensors detect the light beam unless they use prediction, also how is blue generated since theres only a green and violette sensor,mmmm
Also you might think that a single light beam with a color shadown mask or trinitron might be possible by just increasing the speed of the light beam 3 times by alternating between red,green and blue in a row in a certain pattern by moving from one position to the next one and back again,
Also you might think that color turquaze and red could be enough to produce all 3 basic colors ,because when no light is hitting turquaze you will get blue but once you shine yellow light against it you will get green , now just imagine cameras and tv sets only relying on turquaze & red to produce all 3 basic colors, maybe not exactly but close .
You're totally missing the point on how the beam index system works. The beam index still uses three colors red green and blue but unlike a conventional picture tube that has three guns each aimed at the respective color dot or stripe which is aligned using a shadow mask or aperture grille a beam index tube has no aperture grille or Shadow mask and uses one gun like a black and white tube therefore the circuitry needs to know where the beam is as it scans the tube surface two ways this has been done number one with Sony's system that was used on both their trinicon camera system and on the indextron CRT. On the trinicon camera tube there was a metal grid laid out across the target with a separate lead that exited the tube as the beam scanned the target this electrode would detect the beam passing over it and produce a pulse that was used by the multiplex circuit to create a phase lock loop to chop up the colors into the red green and blue components as filtered by the stripe filter on the front of the tube. On the indextron tube there was a fourth stripe added to the backside of the phosphorus on the front you would see red green and blue and then a slight space followed by red green and blue that small space had a UV phosphorus stripe that would emit ultraviolet light but it was painted on the backside of the screen so as the beam passed over this UV stripe it would emit a pulse of ultraviolet light this pulse of ultraviolet light was detected by two sensors that were placed on the bell of the tube I would look into the back of the tube this provided the reference signal to synchronize the phase lock loop to multiplex the three colors into a single switched output so the switched output goes red green blue red green blue red green blue as the beam passes over the tube this is Sony's patented design. Other companies like Hitachi had to come up with their own method of synchronizing the switching for the color circuit they did it by using a yellow and cyan filter in front of photo transistors. The yellow filter would pass light from both the red and the green stripes and the cyan filter would pass light from both the green and the blue stripes if you're following me now you would see that as the beam were to pass over the red and then the green stripe there would be a pulse presented to the yellow photo transistor and then as the beam continued from the green to the blue the second pulse would start as it was passing over the green and continue into the Blue then switch back to the yellow sensor as the beam hit the next red stripe now you have an overlap you have a pulse of light that is only present when the beam is over the red stripe and you have a pulse of light that is only present when the beam is over the blue stripe and you have a wider pulse of light from both detectors at the same time when the beam is over the green so you get basically an overlap so that there's signal through both photo transistors when the beam is over the green but only a single when the beam is over the red and the blue thereby the multiplex circuit knows this is a red and this is a blue and this is a green and it can time the multiplex switch accordingly it's a simple system much simpler than Sony's which required that fourth stripe on the tube the downside is that the photo detectors with their cyan and yellow lenses must be totally shielded from any external light so the only application is building them into the viewfinder where they are far enough back and in behind magnifying lenses and so forth to prevent any external light from reflecting into the sensors which would cause them to lose sink and the picture to turn to black and white.
@@12voltvids woow that’s very interesting.
I understand how it would detect the scan frequency and phase with a PLL by detecting pulses from the red phosphor. But I don't get how this works if you have your camera pointing at, say, something green for a while. If the red phosphor doesn't light up at all, the PLL is not going to get any input and the color generator is going to drift, isn't it?
In other words, doesn't the detector have sensors for all three colors so that it only loses color sync when it shows a black picture?
There are 2 detectors with color filters over the phjto detector. One detects blue and the other one red/green spectrum. This way there are always 2 signals out of phase with each other. There is also a uv stripe that is picked up with the blue sensor and the tubes are biased so there is always a dim glow so even if the picture is black there is enough emission to operate the pll. Once I get the sensor I will be doing a follow up and will show the quality of these little tubes.
Now how did they get away with the beams crossing without total protonic reversal occurring?
( I'm sorry I couldn't help it)
In the CRT the actual place the beams cross over is as they pass through the shadow mask on every drawing I have seen.
There are magnets and correction coils on the bell of the tube to dynamically correct the beam as it travels across the screen.
That's a ghostbusters reference...
You say the high voltage is 5kV because of color, but I guess its not going to be higher than a comparable b&w since it does not have a shadow mask which absorbs most of that extra energy.
Beam index tubes are nothing more than black and white tubes with color stripe phosphor. It's not so much the shadow mask that absorbs high voltage. In fact it is charged to the same high voltage. It is the fact that you have 3 beams being emitted so 3x the electrons plus you need to accelerate them faster to get them through the shadow mask as a high percentage are going to hit the mask and be absorbed by it.
Do you know what would be cool if you took a bunch of those small one inch half-inch CRTs put them in an array and get one of those control box that used to run those multi CRT displays that you would see in malls to get one big picture out of a bunch of small CRTs
HI see for VCR parts to lubricant molykote pg-641 what is similar to molykote pg-641
I would imagine if they were using such a device today, a single chip would have been doing all the colour magic, the pcb would be limited by the size of the lopt.
If it was high volume they probably would have but the color crt viewfinder was a commercial failure because if the poor resolution. Cameras with color viewfinder were restricted to auto focus operation because the color viewfinder (tube and lcd) were not good enough for precise focusing. That is why most cameras used bw tubes.
I had never thought about the focus problem, i can see how poor the user feeback would be with colour.
I watched a black&white tv for years, an old pye rambler portable with a philips tube, it served me well.:-D
A very sharp little picture, i also used it to check the head switching point near the very bottom of the screen scan for vcr checks.
People play with the head guides and control head for some reason??.
i sat there and got the path correct then small tweaks to get the tracking and sound sync right, plus head signal balance and control head amplitude.
I wasted a lot of time helping silly people, but i saved a lot of nice machines from the bin.
@@zx8401ztv
In the TV station I worked there was this ancient conrac under scan (black borders on all 4 sides) monitor with about a 19" tube with an 18" picture. It sat atop the old rca tk20 telecine camera. It had no cover on it, just a bare tube clamped into a metal chassis. The tube was a very long tube and the neck was probably 2" in diameter at the gun. It was solid state, but an early one. It ran 24/7 and for most of the day just had a black raster. If you turned out the lights in the control room you could see the raster. The filament in the back glowing orange. This was used on the telecine when we ran either a slide or were running film. Used by the operator for setup. We would put a chip chart or registration chart up and run a slide projector with no slide so it was a white screen that shone through the test chart which were made out of glass and placed on the lens. The we would use this very high resolution monitor to calibrate the 4 tube camera. This old rca camera had 4 pickup tubes. Red green and blue vidcon tubes for the color portion of the image and a larger monochrome tube, an image orthicon if I remember correctly. It had an amazing, razor sharp picture. You could almost feel the xrays blasting through your body standing in front of that bad boy.
lol free xray at work :-D
I did have a look for the tk20, i stumbled across a tv video camera museum.
The rca section: www.tvcameramuseum.org/rca/rca_list.htm
im sure you have been there.
It was a TK27 telecine.
Here is a picture of it
www.earlytelevision.org/rca_tk27.html
Great video ..... you have a gift
What size would this be considered? I know the smallest traditional CRT with shadowmask is the 1.5" CT-101. Just curious what the smallest beam index color CRT measures in at. Great video btw, just discovered your channel!
This one is 1.25" and so far I only have it working in B/W because I do not have the color filters that go over the 2 detector diodes that sync the color.
@@12voltvids 1.25", thanks! So I guess that means if I were to procure one of these out of an old camcorder I'd end up with a similar color issue?
@@speedyink Yes, they need to be operated as a viewfinder. Had the fella that donated this one sent it to me as the entire view finder rather than scrapping the cabinet then it would probably be working now. The detectors were mounted in front of the mirror that you viewed the screen through and picked up the beam as it flashed across the screen. One was a yellow filter and the other a blue so by averaging they could figure out where the beam was. A goofy way of doing it like the color vidicon tube (and newvicon, saticon ect in cameras) They used a cyan and green stripe filter as well as clear, and used the relationship to figure out color.
Sony did things differently with their trinicon tube, they put a very fine set of vertical electrodes on the surface of the tube that as the beam scanned a voltage would be detected to synchronize the color multiplex circuit, and used a RGB color stripe on the tube.
Sony's beam index was called Indextron, because they used a 4th stripe on the inside of the CRT between the red and blue stripes on the front of the tube. This 4th stripe was UV, so it was invisible, but it strobed into the inside of the tube (as it was placed on the back side of the phosphor on the face plate of the tube.) These UV stripes would flash as the beam swept over them, and was detected by a photo detector glued onto a clear section of glass on the bell of the tube. This provided the synchronization signals for the color multiplexing circuit.
I have an indextron video projector and it is quite cool. Not a super high resolution picture, but as a single tube projector it is usable and quite bright for a CRT. It is liquid cooled. 7" tube.
@@12voltvids Oh, so if I were to procure a full camera/viewfinder, I could still get it to work! I'm looking at cameras like the RCA CKC-021. I know they use a mirror to point the image to your eye, but it's sounding like I'll need to be careful, and figure out that sensor setup. Good info for sure. My idea was to make a little miniature television cabinet for it.
Wow, thanks for the info! Would the Sony KV-4000 use the indextron beam style? That was another set I had my eyes on.
I love this sorta technology, so fascinating.
@@speedyink the kv4000 was a Trinitron. The smallest they made. The indextron was the kvx370 which was a 3.7" 3.5 viewable screen. The indextron sets say indextron right next to the red green and blue ovals in the top left side of the cabinet.
Have you seen post #22 on this page: www.vintage-radio.net/forum/showthread.php?t=62138&page=2 Although I think its an RCA manual, the poster says it describes the Hitachi beam indexing viewfinder...
I have schematics for this viewfinder. Change the last digit 1, 2, 3, and 4 to get all four files.
www.labguysworld.com/SCH_RCA_EVF-32_BEAM_INDEX_COLOR_CRT_001.pdf
For everyone. Enjoy!
This viewfinder most definitely has UV index stripes. The photosensor board had two photocells. One is masked in yellow to block UV and pick up white light, the other is masked in deep blue to pick up the UV index pulse. By clever addition and subtraction of the two photocell signals, the beam index pulse could be recovered very clearly.
I have never worked on this type before I know the detector had 2 photo detectors, didn't know if it used a UV stripe or just keyed off the red and blue. Sony did it different using the detector mounted on the bell of the tube, and having the UV stripes on the back side of the phosphorous
Where those filters external to the detectors, as in mounted to the plastic cabinet that the detectors sit in?
RGB BEAM!
Man i love your vids but again 6 ads during the course of one vid just kills the continuity and really spoils the content, thats why i stopped watching tv. Thanks for sharing.
Unfortunately I have no control over the advertising. That is google that places them, and THAT IS HOW I GET PAID.
So for those thinking of blocking ads, that reduces my ad revenue, and when my ad revenue goes down I start releasing content only on patreon.
Of I could choose to go youtube red, where you have to pay to see. I would rather remain free and ad supported.
When you watch TV the advertising pays for the programming just as it does here. When you subscribe to premium services such as HBO you get no advertising as you are paying for the content you consume.
If you use one of those black market boxes to steal content, then you are a theif and I regard you the same way as I regard people that use ad blockers to watch my content. The solution I have to that it to make my content paid only, or patreon only content. I have some patreon only content now and would rather not go down that road, and won't as long as the ad revenue continues.
I hope you understand how this works. As a content producer I deserve to be paid for my time. I am sure you get paid to do your job, and if your boss asked you to come into work and work for free you would probably tell him where to go, and how to get there.