philco 48-700

[wiseguy]

Now..how many of you can say you own this model..(philco 48-700) special edition set (i am being a wiseguy) with a easy on the eyes green screen???LOL..
kinda hard to photograph,im not sure if its the 7jp1 being green or what..of course this sets original CRT came smashed during shipment,i am impresed on how well it works,its rather a very stable and well focused/bright set for a electrostatic type,i still have like eleven .004 mfd caps to replace..i just stuck it back into the cabinet for the time being,which will be the next thing to work on..really odd set to work on..
and yes i got "bit" a few times with its high current HV supply,it was not too bad..guess i will be the next one looking for a 7JP4..(manual says either 7GP4 or 7JP4 can be used with slight mod)..

[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?

[kbmuri]

http://cgi.ebay.com/ws/eBayISAPI.dll...m=290032750143

[Eric H]

Originally Posted by kbmuri

http://cgi.ebay.com/ws/eBayISAPI.dll...m=290032750143

From the goo stuck to the face of that tube I'd guess it originally came from a Motorola VT-71 or kin.

[Eric H]

Originally Posted by wiseguy

Now..how many of you can say you own this model..(philco 48-700) special edition set (i am being a wiseguy) with a easy on the eyes green screen???LOL..

The Philco/Hoffman Easy-Vision set!

[peverett]

Philco-Hoffman indeed, although my Hoffman "Easy Vision" sets are not quite that green!!!

[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

[kx250rider]

I agree about seeing it in operation, if you get any used electrostatic tube. Whenever I have a spare one to sell on eBay, I quickly stick it in a chassis and fire it up to take a picture. That way the buyer can judge how bright it is, and if it has a spot. And I see a big difference in prices on those too! I've seen $14 for a clean-looking untested one, and I even sold a package of 25 of them on eBay for $150! That was a grab-bag lot untested. But that guy got a deal even if only 2 or 3 were good. But "TESTED GOOD" ones seem to go on eBay for $75 & up.


Charles

[kbmuri]

wise -

I feel bad, wish I hadn't pointed it out. In hindsight, I guess it makes sense that if the RCA tube was obviously used, and the box was a Raytheon, somebody probably pulled the RCA, installed the Raytheon, and put the dud RCA back in the box. Probably a bad combination, to avoid in the future. Mismatched boxes, that is.

Maybe adding insult to injury, but here:
http://cgi.ebay.com/ws/eBayISAPI.dll...m=270034021040

This guy's other auctions are electronics gear too, looks like he probably can handle a voltmeter. Maybe email first and ask him to ohm the filament. Screen doesn't look like it's lost vacuum. If you get if for 40 bucks, and it works nice, it might take the sting out of the other one.

But yeah, I'd be leery too. Once-bitten and all that. Sorry for the bum steer...

-k