Videokarma.org TV - Video - Vintage Television & Radio Forums

Videokarma.org TV - Video - Vintage Television & Radio Forums (http://www.videokarma.org/index.php)
-   Early B&W and Projection TV (http://www.videokarma.org/forumdisplay.php?f=19)
-   -   crt brightners ? (http://www.videokarma.org/showthread.php?t=259317)

Rcr1961 08-24-2013 10:59 AM

crt brightners ?
 
I need a brightner for a 14BP4, I've never had to use one before but,

this crt is really on its last legs, and I need to do something till I can

get a replacement crt. The problem is which model of brightner do I use ?.

I see several on the bay that have the correct base, but how do I know

it will work on my crt ???.

Any info would be appreciated and, if anyone has a 14BP4 to sell, then I

wouldn't need the brightner !.

Thanks

Bob R.

kvflyer 08-24-2013 11:07 AM

Bob,

You may want to start with the question of whether it is a parallel string or series string for the filaments. That should get you started. I think that there were even isolation transformer types for those situations where there was an H-K short...

Rcr1961 08-24-2013 11:17 AM

It is for a parallel filament tv, Thanks

bob

dieseljeep 08-24-2013 12:06 PM

Quote:

Originally Posted by Rcr1961 (Post 3080421)
It is for a parallel filament tv, Thanks

bob

Workman made one they sold as a Super Brightener. It boosted the heater voltage to 9 volts. It's surprising how much abuse those heaters could take.
I used them on the real "sickies". :sigh:

old_coot88 08-24-2013 01:20 PM

:screwy:I've seen brighteners "bootstrapped", ie., a brightener plugged into a brightener, then into the CRT.

Rcr1961 08-24-2013 07:41 PM

Ok, so most brightners just increase filament voltage, with

that in mind I made a voltage doubler, then ajusted a series resistance

till I ended up with 8 vdc across the filiment of the crt.

Now I can see the screen with the room lights on !, a vast improvment,:banana:

for as long as the decrepit 14bp4 lasts.

Anyone got a crt for sale ????, please let me know.

Bob R.

Tubejunke 08-25-2013 12:14 AM

I have one that has a switch for series and parallel. That is my keeper, but I am fairly certain that I have some others. Sounds like your home made job did the trick for now. Great thinking!

kramden66 08-25-2013 01:47 AM

i took a brightener that a set needed and put a resistor on it , the thing sent 10 volts to the crt , after the resistor 7 volts and that little extra is just enough to make a bright picture and better contrast , so thats an idea for others , this way you aren't constantly overdriving it and get a usefull picture out of it , if its too far gone then yes it will need more voltage.

i have seen rare cases where using a brightner for a hour or so after it is removed the picture is better then it was before and stays that way except for a slow time when the set is turned on but rarely does it stay that way.

mike

wa2ise 08-25-2013 02:11 PM

maybe someone in your town has a Beltron, a machine that can fix up CRT cathodes. I used one on a weak CRT in a B&W RCA TV I have, and it made the CRT work without a brightener.


All times are GMT -5. The time now is 07:05 AM.

Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2026, Jelsoft Enterprises Ltd.
©Copyright 2012 VideoKarma.org, All rights reserved.