BY THE WAY: I used the Permatex glass silicone for the base of the CRT. It is very thin and runny. I did not use a lot. After application I stood the CRT on its socket to keep it from running down the face of the tube. After drying it all seems to have run down into the connector base. The socket is glued on but really loose around the tunbe itself. I guess I buggered it up.
Nothing like a little C4 to solve this problem or you could use C4's ugly sister SEMTEX. Ah! there's nothing like the smell of demolition in the morning!
Thanks for the great response folks. I really appreciate all the suggestions and help. It sure would be great if we could all get together one day and share a beer or five! Maybe even a skype video call to talk about restorations and trade war stories????? We have the technology.
@bandersentv That was the stuff. I had seen it on several of your videos but all I could find was a little small envelope for putting back on a rear view mirror. I'll try another store.
Pins 4, 6, 12 and 13 do not connect to elements so you should have 10 wires sticking out. it looks to me like you do. Look at it from the end and compare to the Sylvania data sheet. The wires go in the same order as the pins shown on the sheet.
I once repaired a 7JP4 in similar condition once by salvaging a new base from an old 'scope CRT. It's much easier if you solder a foot long piece of thin wire to the end of each CRT pin to help thread them through the base pins.
BY THE WAY: I used the Permatex glass silicone for the base of the CRT. It is very thin and runny. I did not use a lot. After application I stood the CRT on its socket to keep it from running down the face of the tube. After drying it all seems to have run down into the connector base. The socket is glued on but really loose around the tunbe itself. I guess I buggered it up.
GeoN0JRJ 2 months ago
Nothing like a little C4 to solve this problem or you could use C4's ugly sister SEMTEX. Ah! there's nothing like the smell of demolition in the morning!
Vsshooter 2 months ago
Thanks for the great response folks. I really appreciate all the suggestions and help. It sure would be great if we could all get together one day and share a beer or five! Maybe even a skype video call to talk about restorations and trade war stories????? We have the technology.
GeoN0JRJ 3 months ago
I see Joe has already mentioned the Ebay 7JP4. The item # 180761502501.
I feel your pain George good luck.
73's Jim
k5cxo 3 months ago
If the heater is god you could use an ohm meter to locate the heater wires.
dennis525371 3 months ago
@dennis525371 Of course. That is a great suggestion. Thank you very much!
GeoN0JRJ 3 months ago
I use Permatex glass windshield RTV cement to glue by tube bases on. make sure you use sensor safe RTV and not the kind with acetone in it.
bandersentv 3 months ago
@bandersentv That was the stuff. I had seen it on several of your videos but all I could find was a little small envelope for putting back on a rear view mirror. I'll try another store.
GeoN0JRJ 3 months ago
Respond to this video... Hey Bob, What do you suggest I use to fill the void that will be left on the broken side of that base cap?
GeoN0JRJ 3 months ago
@GeoN0JRJ I'm not sure - I've never tried to patch a broken base before. Maybe some filler like Plas-T-Pair ?
bandersentv 3 months ago
George,
One more thing:
There's currently a 7jP4 being offered on ebay...22-bucks with about 3 days left.
Regards,
John
joernone 3 months ago
@joernone I added it to my watch list! Thanks!
GeoN0JRJ 3 months ago
@GeoN0JRJ Wow! $135.49. I don't suppose you were the high bidder ?
bandersentv 2 months ago
@bandersentv No sir. I let it go. I thought that was high. Was I right in thinking so?
GeoN0JRJ 2 months ago
@GeoN0JRJ Yeah, real high - especially for an untested CRT.
bandersentv 2 months ago
Pins 4, 6, 12 and 13 do not connect to elements so you should have 10 wires sticking out. it looks to me like you do. Look at it from the end and compare to the Sylvania data sheet. The wires go in the same order as the pins shown on the sheet.
bandersentv 3 months ago
I once repaired a 7JP4 in similar condition once by salvaging a new base from an old 'scope CRT. It's much easier if you solder a foot long piece of thin wire to the end of each CRT pin to help thread them through the base pins.
bandersentv 3 months ago
@bandersentv Excellent idea on lengthening the leads.
GeoN0JRJ 3 months ago
George,
Google:
electron tube data sheets - 7
Regards,
John
joernone 3 months ago
George,
Hope this will get you started. I'll keep looking for more:
On the 7JP4, pin #5 is anode one, or focus grid; pin #9 is grid two, or ultor; pin #3 is control grid; Pin #2 is cathode.
Bill Benson (ARF) might have more info. He once built some sort of an adapter to test the 7JP4...I think.
Regards,
John
joernone 3 months ago