[HK-Steve]

Hi to All,

A question about when a projector is turned ON but there is no video signal, i.e. the screen is blank(black) Does this damage the CRT's or reduce their life?Does it stress any other components within the projector in this state?


Steve

 

[Curt Palme]

In general, no. Tubes wear a fraction of the rate in the standby mode (when no light is emitted from the tubes), and I have had many projectors in with 30K + hours with the original tubes still being in good shape.


Curt

 

[thegreataturn]

if the g2 is set right . if the g2 is set too high then without a sig the tubes will still be lit up and wear .

 

[mykl-s]

If you couldn't turn off the AKB line, I assume it would be bad

to leave it running with no video input though??

 

[HK-Steve]

Thanks so far, but I have no G2 adjustment and what is the AKB line?


Steve

 

[thegreataturn]

i'm sure you probably do have g2 ajustment you just don't know you do . if yousay what pj you have someone can tell you where to find it (fidling with it can mess up your grayscale though).


if when the pj has no sig going to it you can still see the tubes lit up then there could be a prob with g2 . if not then don't even wory about it

 

[shanemac]

I hear a lot about "g2" what is "g2"??? could someone please explain.


thanks

 

[HK-Steve]

I have a Sony VPH1020QM dinosaur.So where would the G2 adjustment be located and how do I adjust it?


Many Thanks

Steve

 

[rorox64]

Shanemac,


the G2 is the second grid that the electrons meet after have left the cathode and the first grid (G1).


The cathode (kept continously warm), has a continous, steady voltage level (let's say 140V). A first grid is mounted immediatly after the cathode, and biased very close to 0 V (ground).


If the voltage drops on the cathode, the difference in voltage between it and the anode voltage (34 KV), allow the electrons to win the first barrier (G1) and start their path, oriented toward the anode zone (close to the frontal surface). The G2, biased with some 800-1.2 Kv, regulates the electrons flow in a very fine way, allowing the tuning of the color balancing and level (at the low brightness levels) and the black "threshold".


You could find other 1 or two grids, on the tube, after them... it depends on the tube drawn project, and the usage of the electrostatic focus.



it's a very "quick and dirty" answer, I know...


Romano