Videokarma.org

Go Back   Videokarma.org TV - Video - Vintage Television & Radio Forums > Early B&W and Projection TV

We appreciate your help

in keeping this site going.
Reply
 
Thread Tools Display Modes
  #136  
Old 02-21-2014, 05:09 PM
wiseguy wiseguy is offline
VideoKarma Member
 
Join Date: Jun 2002
Posts: 382
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.
Reply With Quote
  #137  
Old 02-21-2014, 06:20 PM
Eric H's Avatar
Eric H Eric H is offline
Administrator
 
Join Date: Jun 2002
Location: So. Calif
Posts: 11,565
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.
Reply With Quote
  #138  
Old 02-22-2014, 10:12 AM
CaryLee's Avatar
CaryLee CaryLee is offline
VideoKarma Member
 
Join Date: Dec 2013
Location: Farmington, New Mexico
Posts: 108
Quote:
Originally Posted by kramden66 View Post
here are some pics of the sister to your Dumont , the ra-109
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.
Reply With Quote
  #139  
Old 02-22-2014, 10:17 AM
CaryLee's Avatar
CaryLee CaryLee is offline
VideoKarma Member
 
Join Date: Dec 2013
Location: Farmington, New Mexico
Posts: 108
Quote:
Originally Posted by wiseguy View Post
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.
I don't have much to add having little experience with various CRT's. It does look kind of bluish in the photo, but it is a good clear picture. I wonder if you would notice the tint if you didn't have anything to compare to?

Do CRT's have a "break in period" when they are new? Might it settle down a bit with use?
Reply With Quote
  #140  
Old 02-22-2014, 11:32 AM
Phil Nelson's Avatar
Phil Nelson Phil Nelson is offline
VideoKarma Member
 
Join Date: Jan 2006
Posts: 4,030
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
Reply With Quote
Audiokarma
  #141  
Old 02-22-2014, 12:02 PM
jr_tech's Avatar
jr_tech jr_tech is offline
VideoKarma Member
 
Join Date: Sep 2009
Posts: 4,510
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
Reply With Quote
  #142  
Old 02-22-2014, 12:06 PM
Kevin Kuehn's Avatar
Kevin Kuehn Kevin Kuehn is offline
Workin' Late Again
 
Join Date: Jan 2011
Location: WI
Posts: 3,824
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.



Reply With Quote
  #143  
Old 02-22-2014, 01:34 PM
Phil Nelson's Avatar
Phil Nelson Phil Nelson is offline
VideoKarma Member
 
Join Date: Jan 2006
Posts: 4,030
Quote:
Originally Posted by jr_tech View Post
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.
That reminds me, I saw that effect when I reinstalled a CRT in my RCA T-100. What's causing those faint blue areas on opposite corners, I wondered? Then I realized that if I rotated the tube and reduced the height to normal, they would exactly match the areas never scanned by the electron beam. The center portion that had been scanned was warmer in color.

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

Reply With Quote
  #144  
Old 02-24-2014, 02:27 PM
wiseguy wiseguy is offline
VideoKarma Member
 
Join Date: Jun 2002
Posts: 382
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.
Reply With Quote
  #145  
Old 02-24-2014, 02:51 PM
holmesuser01's Avatar
holmesuser01 holmesuser01 is offline
VideoKarma Member
 
Join Date: Jul 2005
Location: Asheville NC
Posts: 1,731
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.
__________________
Bruce
Reply With Quote
Audiokarma
  #146  
Old 02-24-2014, 03:05 PM
bandersen's Avatar
bandersen bandersen is offline
RCA 741PCS
 
Join Date: Mar 2009
Location: Chicago, IL
Posts: 8,085
Maybe you have a 19AP4A or 19AP4B which have grey tinted/frosted faces ?
__________________
Here are my Vintage Radio & TV YouTube Channel and Photo Gallery
Reply With Quote
  #147  
Old 02-24-2014, 04:05 PM
cwmoser's Avatar
cwmoser cwmoser is offline
VideoKarma Member
 
Join Date: Dec 2009
Posts: 552
Quote:
Originally Posted by wiseguy View Post
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

Wow. That is a georgeous TV.

Carl
__________________
CW
1950 Zenith Porthole - "Lincoln"
Reply With Quote
  #148  
Old 02-24-2014, 04:31 PM
wiseguy wiseguy is offline
VideoKarma Member
 
Join Date: Jun 2002
Posts: 382
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.
Reply With Quote
  #149  
Old 02-24-2014, 06:06 PM
Username1's Avatar
Username1 Username1 is offline
Not sure how I got here.
 
Join Date: Dec 2009
Location: Orange County NY
Posts: 3,584
Quote:
Originally Posted by cwmoser View Post
Wow. That is a georgeous TV.

Carl
What he said !
__________________
Yes you can call me "Squirrel boy"
Reply With Quote
  #150  
Old 02-24-2014, 06:32 PM
Dave A's Avatar
Dave A Dave A is offline
VideoKarma Member
 
Join Date: Aug 2003
Location: SE Pennsylvania
Posts: 1,529
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.
__________________
“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
Reply With Quote
Audiokarma
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 12:20 AM.



Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
©Copyright 2012 VideoKarma.org, All rights reserved.