View Full Version : To clean or not to clean

05-26-2013, 08:47 PM
The only way to clean the screen of a dumont ra-109 is to remove the crt - should i risk it? we know these crts are metal/glass .

i put a replacement 19ap4 in a ra-110 and it looks nice cleaned up .


Sandy G
05-26-2013, 09:48 PM
If you decide to do it, PUH-LEEZE Be Careful...

05-26-2013, 10:53 PM
If you decide to do it, PUH-LEEZE Be Careful...

Are the 19" metal cone CRTs particularly hazardous? (other than the shock hazard)... I have never handled one, but remember the 16" metal cone CRTs being quite sturdy.


05-26-2013, 10:57 PM
You really shouldn't have any problem. Up in the attic I have a metal/glass tube that I found at an antique mall-they had it sitting outside in front of the store for months! Rusty, but still under vacuum. It tests good but I've never tried it in a set. Anyway, they aren't that finicky.

05-26-2013, 11:44 PM
Just don't ding anything metal/glass and let the air in... Contrary to popular believe, CRT's are pretty stable. The only one I really cringe around is my 15GP22, I handle that one with kid gloves.

Eric H
05-26-2013, 11:56 PM
Those aren't particularly fragile, just be careful around the rim of the face and don't carry it by the neck.

Oh, and turn off the set before you remove it. :D

Phil Nelson
05-27-2013, 01:59 AM
It's usually worth the effort to clean the safety cover and the face of the CRT. You might be surprised how much grime comes off a set that didn't look especially dirty at first glance. Even a clean house has stuff in the air -- fumes from frying food, etc. -- that can accumulate over the years.

Phil Nelson

05-27-2013, 06:46 AM
I would ground the Anode, and ground the Anode again.

I remember finishing my work on my Raytheon Porthole out in the garage
and preparing to put it back in the cabinet in the house. I discharged the Anode
and went to open the door to the house. Back at the chassis, my concern for
safety wanted me to discharge the Anode once more before I toted the chassis
in the house -- I observed a spark upon grounding the Anode the second time.
That would not have been good thing if I got shocked while carrying the chassis
with the attached 16AP4 CRT. So, I put a aligator clip between the Anode and
Ground while I carried it in the house.

Respect those HVs.


05-27-2013, 08:31 AM
Since I think the question has been properly answered, I hope you don't mind another true story. Dad was carrying the CRT from our first TV, and Admiral to the store for trade-in. Picture walking on Howard St. in downtown Baltimore, Radio Electronics the store (if I remember correctly). All of a sudden, he starts juggling and squirming. The anode bit him! I am sure he had discharged it but the charge had built back up as you know. I was only about 5 or 6 at the time.

05-27-2013, 04:17 PM
My first really old set was an RA-109. I got it in about 1983 and it had been sitting in a storage building of a junk/antique dealer for a number of years giving homes to local field mice. Oddly, the man running the store was the area's first television sales entrepreneur and he had sold the set new back around 1948 or so to the wealthy president of Stanley Furniture Company. It came back to him as junk in the late 70s.

I always think that this story is fascinating and regret having to let the monolithic set go (as usual) for space needs sometime back in the late 1990s. At any rate, I remember a nasty looking bunch of black cobweb looking stuff had somehow made way behind the safety glass, so this was my first crt pull just to get the dirt out. It was not very hard to do, but I remember being real nervous having read the shock hazard stickers on the tube as well as reading up on the subject of handling crts in a real good book that the library had back then.

I have had a love and fascination with the DuMont company and the sets of their good years although I never have never managed to find another one. What I want is a round tube table model. Gonna be hard pressed to ever find one within driving distance.

Eric H
05-27-2013, 06:07 PM
The 19AP4 is a metal tube and stores no charge. The HV filter caps in the set might though.