philco 48-700

[cbenham]

Originally Posted by John Marinello

I had a VCR a while back that used a green fluorescent display. I didn't know that until I opened it up because the display appeared white. What I found was that they added a "red" filter in front of the "green" display. Apparently green + red = white. Has anyone tried this on their P1 tubes?

Here's something that sort-of worked for me:
You can try using Rosco lighting gel (it's not the old style water soluable gelatin, its a very robust polycarbonate plastic film 'sandwich' which will last for years in CRT color correction use)
to make a P1 tube look B&W.

The ones I tested for P1 correction are:
#47 Light Rose Purple, transmission characteristic = 16%
#48 Rose Purple, transmission characteristic = 16%
#58 Deep Lavendar, transmission characteristic = 10%

Please Note:
The transmission characteristic of these three 'gels' is very low so, although you will see a B&W picture from your P1 tube, it will be quite dim and probably viewable only in a darkened room. You will get only 10% to 16% of the light emitted by the tube through the gel filter, 1/2 to 2 foot-lamberts. Pretty dim.

The better idea is to somehow find a P4 CRT.

If you try out the lighting gel, you might want to first get a Rosco 'swatch' book with samples of all their gels so you can determine for yourself which one works best for your P1 tube.

Rosco 'gel' is available from theatrical lighting supply companies and over the internet from Amazon for about $6 a 2X2 foot sheet.

Good Luck!!!!

[wiseguy]

well i did it again,this is the 2nd 7jp4 that i won off of e-bay that is dead..both had boxes included,odd thing someone had tried to glue the socket back on on the first one and its gone to air,you can even see the super glue running down INSIDE the neck of the tube,the other 7jp4 i won a few days a go
was in milwaukee,so yesterday i took off of work early and drove there,this one also with box,as soon as i got hope i tried it,it is dead,dead as in dead..with no revival even on my 1500.00 sencore crt analyizer..it looks cooked around the filament like it had many hrs on it..back to green screen time..i guess you cant really buy any of these tubes unless you see its operation first..
so used 7jp4's off of e-bay is a big NO-NO,and a what a waist of time and money