|
|
|
#3
03-10-2009, 02:10 PM
|
|||
|
|||
|
I dont need one at this point . I am restoring a rca kcs72a , which uses that tube . The set came with a tag stating it was replaced with that tube . The beltron tester tests it ok however its takes a little more time then normal to get up to where it should be on the meter .The bakalite socket got cracked due to my being a bit clumsy but it repaired ok . Anyway i think the tube will be ok . Was just curious if there was a cross for it becuase i have a bunch of NOS crts in my attic and was kinda hoping one would fit . My cross ref book says no cross avail . This chassis had a lot of caps in it , over 40 caps replaced , not including the micas which are still in there .
|
|
#4
03-10-2009, 05:45 PM
|
||||
|
||||
|
There is a 21MP4 at the ETF site, under parts. That one is an electrostatic focus, while the 21AP4 is a magnetic focus. Maybe you can make it work?
|
|
#5
03-11-2009, 10:40 AM
|
||||
|
||||
|
You can convert to a 21" glass tube of the same deflection angle (should be 70 degrees), without too much trouble. Just replace the anode lead, and remove the doorknob capacitor from under the high voltage rectifier tube. The mounting can sometimes require a little engineering, but it's certainly possible to do!
To put an electrostatic focus tube in place of the magnetic focus tube, remove the focus magnet, and put a jumper from the focus pin to the pin next to it (they made a special flat jumper do do this). If the old magnetic focus coil is electric, you need to check to see if it's also being used as a filter choke in the power supply. If so, either relocate it under the chassis and wire it in, or replace it with a choke from another device that uses similar current to the TV. Charles
__________________
Collecting & restoring TVs in Los Angeles since age 10 Last edited by kx250rider; 03-11-2009 at 10:44 AM.
|
| Audiokarma |
|
#6
03-11-2009, 12:52 PM
|
||||
|
||||
|
Quote:
-Tony
|
 |
|
|
Linear Mode
