tube swap questions

[Beretta]

ok so i have a few 19 inch monitors.. one of which im wanting to use in my project.. problem is the burn in is pretty harsh on them.

i've been picking up tv's this last week so far all of them but one turned out to actually be 20 inch instead

the one that actually was a 19inch looks like the first color tv kinda old it was absolutely covered in PCB's wall to wall and used vacuum tubes.

anyway i took off the neck board (which was really just a ring with some wires on this.. no real neck board) and it was a 12 pin.. but all the reading i had been doing said that 13-20 inch should be 8 OR 10 pin, and that all 21+ are 10 pin.

so my question is where did this 12 pin tube come into play?

also it was 36mm neck which is larger then the other 19-25 inch i've been seeing, that measure 29mm


anyhow i also measured the ohms of the yoke on 3 of the 19 inch im needing to replace.

WG: 4906 = 36.6 (vert) / 3.0 (horz)
WG: 4901 = 37.0 (vert) / 3.0 (horz)
EH: g07 = 54.0 (vert) / 2.4 (horz)
all of them are 10 pin.

the 2 WG are in the same family and are so close im thinking it's probably just variation from monitor to monitor do these measurements look right?

how close do i need the yokes to match up?
are both measurements important or is the vertical windings the more important?

i take it i should be able to match up a low resistance yoke with a chassis expecting higher impedance by adding some resistors to the circuit?

my understanding is as long as the tube is the same size 19 inch, neck is the same size 29mm, and has 10 pins that it should work although i may have to swap the yoke? is this correct or is there something else that determines rather or not a tube is compatible?

sorry for the long post and probably noobish questions but im learning as i go and it's my first time so i need some hand holding.

[Ken Layton]

There are different pinouts on some tubes even though they have the same number of pins. Look the tube number up in the B&K rejuvenator setup manual. If the tube number shows it using "CR23" adapter, then it's usable as an arcade tube.

Be aware that Electrohome's yoke connector pinout is different than most other monitor manufacturers.

[Beretta]

ah yes i looked for the tube type on the monitors.. i was unable to find the tube type on the 4901, or the G07.

the 4906 however had it marked on it's sticker "19vlp22"
which i could'nt find on the chart but the other 2 are, im thinking i must have missed a letter when i was writing it down so i'll go back and double check..

the chasis on both the WG had a sticker that said tube type

19vlp22
19vmcp22
19cmkp22


so i took that to mean that any of those 3 tube types would work with the chasis.

how can i tell what type of tube it is if it's not marked? it's usually on it's sticker right?
also i see a lot of those CR-23's any of those will work even though only 3 of them are listed on teh chasis? perhaps later model tubes that was'nt around when it was made?

if they are all compatible what makes them different i wonder? i mean why so many tube types.

[Beretta]

ok i double checked looks like i made a mistake i left out a letter the tube currently on the 4906 is 19VLTP22,

anyway i picked up another tv tonight it was a sony, it has a sony trintiron screen.

the tube type is a51ldg50x.. which is on the chart listed as a 23, so does this mean it will work even though it's a trintiron tube & the original is'nt?

also the vertical measured 12.0, so could i just add a resistor(s) to get it near 36/37? will that work?

the horizontal measured out 4.0, the original tube's yoke measured 3.0.. is this close enough? if not then i can swap yokes correct?

how close do these need to be? i really wanted to avoid messing with yokes.

[Beretta]

BAH! i just noticed today that it's not a 19 inch tube, it's actually a 20inch tube 
why can't i find any 19 inch tubes? all these 19 tv's end up actually being 20 inch 


oh well i've ran out of sources for tv's for a while i wanted to practice this on one of the 19 inchers i got first, especially since thats what i need for my projects RIGHT NOW & they need the swap much more then the 25 i got.

anyway i went though some of the 25 inch tv's i got recently.. and think i found a match.

the original is a WG7000 series (25k7131)
tube type = GA63ADG25X
getting the yoke connector off the chasis was a total PITA.

after i got it loose i notice teh connector looks like it's been melted or something.. weird.. also the terminals on teh tube for the yoke wires had some sort of epoxy on it so i had to take the measurement from teh connector instead of directly on the yoke.

i thought perhaps the tube had been swapped before (to account for the damaged connector) but the serial numbers match on the chasis, frame, tube, so i reckon it's original.

anyway the original read 11.2ohms for vert & 1.9 for horz.

one of the tv's that look to be a match is a sanyo, with a philups tube (MVA63AFW40X)
which going off the B&K manual both have the CR23 connection like you said.
and they both have a 29mm neck some im guessing this would make a suitable tube.

it's yoke read 8.3 vert, 1.8 horz..

so it's 11.2 / 1.9  VS 8.3 / 1.8

so i figure the horizontal is close enough not to need any change only .1 ohm difference.

the vertical is 3.1 ohms diff.. would it be possible to add a couple 1ohm resistors and just swap the tube AS-IS, without having to mess with the yoke?

if so what wattage of resistor would be needed?

[Crowsen]

19 inch tubes you can buy cheap at Casinotech in VEGAS. 702.736.8472 ask for Kimberly VanVeen

[Beretta]

thanks for the suggestion, but i dont think that'll be plausible.. im in ohio even if the tube was free the shipping would be a killer, i'd be better off getting a 8liners chassis for a 20 or 25 inch.