Posts: 1,130
Threads: 79
Joined: Jan 2014
City: Annapolis, IL
Hey all, I have a question about this type of picture tube (16AP4). This is a 16" round tube with a metal bell. The 12kv high voltage connects to the metal bell of this tube and is supported by 4 insulated grips screwed to the inside of the cabinet. One has a contact that feeds the HV into the tube. Im not really fond of this, but since this tube very low, almost flat, I wondered of anyone knew if this could be replaced with an all glass tube or had any experiance/ advice about this type of tube? Never dealt with one of these before.
Many thanks!
If I could find the place called "Somewhere", I could find "Anything"
Tim
Jesus cried out and said, "Whoever believes in me , believes not in me but in him who sent me" John 12:44
(This post was last modified: 09-17-2014, 09:15 PM by TV MAN.)
Posts: 51
Threads: 9
Joined: Oct 2005
City: Warren, OH
You can use an all glass tube. As long as you keep it clean, the metal tube will work as designed. With metal tubes, for troubleshooting, I use a 5AXP4 test tube.
Visit the world's worst TV restoration website.
http://evilfurnaceman.tripod.com
Posts: 1,130
Threads: 79
Joined: Jan 2014
City: Annapolis, IL
Thanks for the advice. I had wondered how I could service the chassis since the tube was mounted to the cabinet, and the deflection yoke to the chassis. I had thought of using some 2x4's to support the tube, but one mistake, and there goes the neck of the tube or 12kv worth of fun! Or both!
If I could find the place called "Somewhere", I could find "Anything"
Tim
Jesus cried out and said, "Whoever believes in me , believes not in me but in him who sent me" John 12:44
Posts: 797
Threads: 42
Joined: Dec 2008
City: Chicago, IL
Posts: 1,130
Threads: 79
Joined: Jan 2014
City: Annapolis, IL
Thanks Bob for the info and posting the pictures! Most of the tvs I have worked on have the picture tube mounted to the cabinet and yoke mounted on the neck of the tube. I could usually pull the chassis and flip to where I could service. Most of the older sets have the tube mounted to the chassis, making removal and service simple, but heavy. I really didnt know how I was going to deal with this set. On a good note, I had read somewhere an article about how companies were "recycling" tubes back in the 50's I think, and would cook the filaments to rejuvinate. This tube would barely move the needle on the tester/rejuvinator when I first tested it. I think the set has been idle since the 1960's. I left the tester on the heater (6.3v), then turned up to 8v for about 1hr. When I returned it to 6.3v, let it sit for several minutes, the reading had raised to the high side of 'bad', to just under the '?'. I may do this again and see what I get. Should be enough to run the set now. I dont know long this will last, but I doubt I will ever use the set enough (after recapping/repairs) to pull the tube down. I am reluctant to do a 'rejuvinate', as I have seen some tubes lose focus and sharpness. I think I read it also strips some of the emission coating from the cathode, and enlarges the hole in the end of the gun.
I will start searching for one of those test tubes.
Thanks again Bob
If I could find the place called "Somewhere", I could find "Anything"
Tim
Jesus cried out and said, "Whoever believes in me , believes not in me but in him who sent me" John 12:44
Posts: 1,130
Threads: 79
Joined: Jan 2014
City: Annapolis, IL
Since my last post, I have been patiently waiting for one of those tubes to show up on ebay. I found one and it arrived a couple days ago. It tested perfect. Wow, finally something from ebay that IS as described! It was well pack and survived the USPS abuse! Had to thank that seller! Anyways, it is an 8XP4. Before I try this, I need advice if I can use the ION trap magnet from the 16" tube, or what you may recommend. I doubt this is an aluminized tube.
I am still 'aways' off from getting my bench set up. Seems when I started this about a month ago by cleaning out a room in my attic - then, somehow, it took the detour of becoming my sons room, which meant more cleaning to the very back room in the attic, in which I discovered "mouse central". Soooo - now, I am remodeling that room to mouse-proof, the next room for my son, then finally, his old room will become will become 'my tv/radio' shop, man cave - eh' ya get the picture... whole other story here... gonna be a while before I can warm my soldering iron.
If I could find the place called "Somewhere", I could find "Anything"
Tim
Jesus cried out and said, "Whoever believes in me , believes not in me but in him who sent me" John 12:44
Posts: 49
Threads: 0
Joined: Jul 2007
City: Denver CO
8XP4 does not need an ion trap. It also is self focusing so do not use a focus magnet with the test tube. It only needs the yoke, CRT socket and high voltage.
Don
Posts: 2,128
Threads: 18
Joined: Oct 2008
City: Merrick, Long Island, NY
Agree, can't recall ever having used an ion trap with a testing CRT, but it's been many moons.
Users browsing this thread: 1 Guest(s)
|
Recent Posts
|
Jackson 715 not working
|
Mrfixr55, its working now. I cleaned the switches and sockets with spray cleaner. Thanks for helping on this one.daveone23 — 06:26 PM |
Jackson 715 not working
|
Now that you posted the schematic, I don't know why that Sprague electrolytic cap is across the meter, as it is not indi...MrFixr55 — 05:51 PM |
HiFi (Chifi) tube amp build - but my own design.
|
What may be lacking in the PP Tube amps may be the 2nd harmonics, which some, especially RCA back in the day called &quo...MrFixr55 — 05:32 PM |
Jackson 715 not working
|
Usually in an emission tester, the tube under test is measured as if it were a diode. So, some testers connect all the g...RodB — 04:17 PM |
Restoring Philco 37-604C
|
Yep. F5 is green, D5 is Red.
Red is Bad.
Green is Clean.morzh — 01:30 PM |
Jackson 715 not working
|
I did start to do that but I stalled out because I could not figure out how the grid and plate get voltage. In this diag...daveone23 — 11:52 AM |
Restoring Philco 37-604C
|
(Insert Homer Simpson "DOPF" Here.)
When all fails, look at the can. Took the Ron Ramirez advice, red Caig D...MrFixr55 — 09:23 AM |
Philco 91 Speaker Replacement
|
From your text I am not sure if you intend to use the existing speaker with a resistor instead of the field coil.
It wo...morzh — 08:44 AM |
Philco 91 Speaker Replacement
|
My field coil is bad. I am still hoping to find an original, but if I can't I will go with a fitting Philco speaker, 125...dconant — 08:34 AM |
Philco 91 Speaker Replacement
|
As Rod said, it is OK to use a fitting speaker, and then look for an original one.
If you buy a Hammond 125 output tr...morzh — 08:15 AM |
Who's Online
|
There are currently 3938 online users. [Complete List] » 1 Member(s) | 3937 Guest(s)
|
|
|
|