#136
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Nos 19ap4
This is a afternoon shot with a Nikon DSLR this time
This is a NOS 19AP4, guess I should have left the sort of weak one in. Last edited by wiseguy; 07-19-2016 at 01:00 PM. |
#137
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When was that NOS 19AP4 made?
I know there are differences between tubes made in the 40's-50's, the phosphor is a uniform color, B&W tubes from the 60's-70's seem to have a different formula, if you look at them up close while on you can see yellow and bluish colors in the mix. I would assume it was done to make the image look brighter, like adding Bluing to wash makes it look whiter. |
#138
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Wow! That's a rock-solid, dead on, straight and uniform picture!
I still have a couple issues with the adjustment on mine..sometimes people's foreheads and hairdos seem to get a bit bigger towards the top of the screen. I tried my test pattern disk in a newer DVD player and it worked. It won't play in the older dvd player I have hooked up to the DuMont. Now I have to decide if I want to go through the hassle of unhooking the newer DVD..it's pretty tough to get to the wires, and there's a 30 gallon aquarium on one end of the hutch it is in..so easily moving the furniture to get to the wires in not an option. I might have to commandeer my son's Xbox 360 temporarily to use as a DVD player...if IT will play the disk. |
#139
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Quote:
Do CRT's have a "break in period" when they are new? Might it settle down a bit with use? |
#140
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I'm still curious to see what it looks like in total darkness. Hold the camera right in front of the screen and photograph nothing but the image on the CRT (not even the green tuning eye).
Phil Nelson |
Audiokarma |
#141
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White P-4 phosphor on early CRTs is actually a mixture of two different phosphors. One component is yellow and the other is blue. Combined in the correct ratio the mix produces a decent, fairly uniform white.
Sometimes I have observed, when re-installing a round P-4 CRT after work on the chassis, that orientation of the CRT is critical otherwise "blueish" areas of the CRT are illuminated. I suspect that the blue component of the P-4 phosphor ages more rapidly, and over time the used areas of the tube become "warmer" or more yellow. Likewise, I would postulate that a new P-4 CRT would very likely be bluer than a well used one. jr |
#142
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I think Phil is correct that it has to do with light balance in the room. Here's a couple shots(bad focus) of the 19AP4 in my Sentinel. Notice how when more of the back lite room is showing that the picture takes on the blueish tint. Somehow I always end up with a reflection of my GE clock on the screen.
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#143
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Quote:
The color difference was subtle. It didn't really register in a photo unless I cranked up the contrast & brightness beyond normal levels, high enough to make retrace lines. Phil Nelson |
#144
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bluish 19AP$
sorry been busy, but No it's blue with my eye as compared to the old one, I know white balance all too well as I worked on in Broadcast Video Service and Working for the Packers in Replay.
I noticed this right away after I was just bored and replaced my old Slow warming 19ap4, I only did this because I had 2 N.O.S Tubes from the same person, not Rebuilt but NEW from Dumont but like 3 years newer or so..its a pain to replace, and you get used to it but I noticed the Blue right away. here is a pic from the same set before and using the Exact DSLR Camera with the old original CRT . I'll just have to get used to it, maybe for kicks I can push a RCA 630TS next to it and Take a few more pictures and compare. but it seems that I remember someone Noting the same thing many years ago on this site, like 12 yrs ago or so. but my eye notices in person that its blueish for sure Also maybe it does have to be Aged in like others have Said, I'll run it for hours and see. and I have found out that you can't blast away the Contrast or Brightness or you will get Retrace. I had pulled the whole chassis and checked it out, these Tubes for sure are not super Bright, it would be nice to find an Aluminized one, but those must be rare, I know they were made that way, I think Tung Sol shows it listed Last edited by wiseguy; 07-19-2016 at 01:00 PM. |
#145
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I remember seeing B/W sets in the showrooms of department stores back in the day, and noticing the differences in the shading (color) of the CRT's on them.
We had a GE 19" set from around 1963 that was literally blue-white looking.
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Bruce |
Audiokarma |
#146
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Maybe you have a 19AP4A or 19AP4B which have grey tinted/frosted faces ?
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#147
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Quote:
Wow. That is a georgeous TV. Carl
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CW 1950 Zenith Porthole - "Lincoln" |
#148
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OK here We go, 3 Pictures to amuse you
a 630ts to the left and the last picture notice the White cat. sort of a pain to push and move all this. I never looked to see if it had a Tinted face..I think they are a A version one of these tubes was mounted in another set, but was not used so I am confused about the tint. it's Noticeable in my eyes. but Really a grey tinted face would Give a Blueish tint? I should have posted a new thread about this instead of posting in Gary's thread, but didn't know it would go this far Last edited by wiseguy; 07-19-2016 at 01:00 PM. |
#149
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__________________
Yes you can call me "Squirrel boy" |
#150
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One good way to judge color is to stand back from the set in a dark room and see what the CRT is doing to illuminate the room. Is it bluish or greyish? The poor cameras are working overtime in a dark room trying to make something white...walls, lamps or the white Persian cat can all throw it off. Try taking a photo in a manual white balance set for cloudy...a higher kelvin temp closer to a CRT. This will fix the camera on a specific kelvin temp setting and you can then see what your CRT is doing in that neighborhood. It will also throw the surroundings very red as it tamps down the blue.
And on the sound IF tweek. Which is the best direction to adjust by ear? From the split to the end amp or backwards from the amp? And upper or lower adjustments first if the can has both? I did this with a Pilot TV-37 set to a good pix and had good luck going from the beginning to the amp.
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“Once you eliminate the impossible...whatever remains, no matter how improbable, must be the truth." Sherlock Holmes. Last edited by Dave A; 02-24-2014 at 06:38 PM. Reason: typo |
Audiokarma |
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