Need a 10BP4 Pic Tube
 

I picked up an Admiral dual chassis (1948) and have it all ready to go... except I just found that the filament is open on the picture tube. I hope someone knows where I might find one, as I have put a lot of time into this chassis (full recap). Yes, I shoulda checked the pic tube first, but the last user reported that it worked when they put it into storage. Could shipping have opened the filament?

Dan

Dan, as a rule the heater is tough as nails, they can take 12 volts and still not burn out.

Try resoldering the pins on the base, you may just have a bad connection.

The heater pins are #1 & #12 the ones on either side of the index key.

Heat the pins, one at a time and touch a dab of solder to the ends. it should wick inside the pin and restore the connection.

Eric

I have seen some cases where the CRT cracked inside the yoke or in some area that is not clearly visible. Air then gets in and contaminates the tube and even though there is filament continuity, it won't light. Theoertically it is possible that the CRT got hit in just the wrong place during shipping and a crack developed. Check the continuity on the CRT filament---also check and make sure you have filament voltage to the CRT, sometimes it is on a seperate fil. winding. The solder suggestion from Eric sounds good as well if you find there is no CRT continuity and that the filament voltage is present.

This thing acts strangely... one measurement and it is open and on another it is fine. I removed the tube and did the soldering trick and seemed to get good continuity right afterwards, but hours later I measured open again. Waited a few minutes and it was fine again. This is using ohmeter, not filament voltage. So I hooked up 6.3vac directly and so far all is well. The filament glows and has on repeated occasions. I sure wonder why the ohmeter varies from time to time. If someone has seen anything like this before, let me know. BTW, thanks for the very helpful advice, this may have saved me a lot of trouble and money... knock on wood. I will keep you posted. For now, tube is out and I am cleaning chassis and reforming some lytics before I reinstall.

Dan