RCA CTC-17 black matrix tube and chassis - Videokarma.org TV - Video

Chad Hauris · #1 07-01-2006, 06:07 PM

Someone donated to us an RCA CTC-17 chassis and 23VALP22 black matrix CRT...they were going to install a new set in the old cabinet. They gave us all the paperwork that came with it. The tube looks in good shape...I may try and assemble the set and try it out. I don't know if I will use this tube and chassis to get some other sets going or try and reassemble this unit into another cabinet. The CRT was replaced in 1978.

Chassis large:
http://www.retroaudiolab.com/picture...c17chassis.jpg

Hang tag outside
http://www.retroaudiolab.com/picture...tagoutside.jpg

Hang tag inside
http://www.retroaudiolab.com/picture...gtaginside.jpg

Hi Lite Picture tube warranty front
http://www.retroaudiolab.com/picture...ewarranty1.jpg

Hi Lite Picture Tube Warranty rear
http://www.retroaudiolab.com/picture...ewarranty2.jpg

1978 Service invoice
http://www.retroaudiolab.com/picture...iceinvoice.jpg

Tube large:
http://www.retroaudiolab.com/picture.../ctc17tube.jpg

Chad Hauris · #2 07-01-2006, 06:59 PM

I decided to hook it up and test it...when I first plugged it in the picture tube displayed light but it got dimmer till there was nothing. There is HV and the sound and tuner/IF appears to work.There is a blue glow in the CRT neck that varies with the screen control adjustments...there is no arcing though. Hope the CRT isn't bad. Tried tapping gently on the CRT neck but no change.

Test rig-up large
http://www.retroaudiolab.com/picture.../ctc17test.jpg

CRT glow large
http://www.retroaudiolab.com/picture.../ctc17glow.jpg

jpdylon · #3 07-01-2006, 07:58 PM

Sounds like a case of bad gas (pun intended) I had a GE set that had a CRT with the same problem. It would come up ok, but would fade to black, while sweep and HV remained. I had a nice blue glow at the neck similar to yours.

Would be a bummer if that tube is toasted...

Bobby Brady · #4 07-01-2006, 10:50 PM

I would bet a dollar to a donut that tube has gone byebye.
I heard that any blue in there means air is in the tube. I suppose it is a micro amount but I wonder what is actually making it blue? I think that is simply an effect of the air in the partial vacuum burning by the filament heat/voltage.
Am I correct?
Soon we will get the facts from one of the many generous and knowledgeable members!

Bobby Brady · #5 07-01-2006, 10:56 PM

Hang tag outside
http://www.retroaudiolab.com/picture...tagoutside.jpg

Cool hang tag!
The Burgoyne!
Can someone please tell us what a Burgoyne is? I know it is a name of a TV cabinet design but what in the heaven's to Betsy did they pull that name out of?
Just wondering.

andy · #6 07-02-2006, 12:24 AM

Is the blue glow between the gun elements, or on the inside surface of the glass? If it's only on the glass, the CRT might be ok, but if it's all around the inside of the gun, the CRT has gone very gassy.

3Guncolor · #7 07-02-2006, 12:32 AM

Check the focus voltage if it and the other CRT voltages are correct tube is bad. It could be a problem with the focus as I remember that tube needs 4k to 5k volts to operate.

Bobby Brady · #8 07-02-2006, 12:57 AM

Quote:

Originally Posted by 3Guncolor

Check the focus voltage if it and the other CRT voltages are correct tube is bad. It could be a problem with the focus as I remember that tube needs 4k to 5k volts to operate.

That is interesting.
Has anybody ever seen a CRT with blue glow in the neck produce a good picture?

3Guncolor · #9 07-02-2006, 10:24 AM

If they have the glow I would say no they do not work. I have had sets with incorrect voltages on the CRT gun and they would have a blue glow and after the problem was corrected the glow was gone. Just one last thing to test for before the tube is junked.

Chad Hauris · #10 07-02-2006, 12:36 PM

Thanks guys for your help. I have seen the blue glow on definitely bad tubes which appears as kind of an arcing between the elements...this glow is on the glass of the tube, kind of like you will see on a 6L6GC audio output tube or EL34 etc. I think I may go ahead and try the tube on a chassis that I know works 100%. This was the best 23" tube RCA made so I won't junk it without some more testing.
I didn't get much of a spark when I discharged the HV so there may also be weak HV.
Alternatively I may slip the chassis into another set with a known good CRT and see how it performs. I didn't really get into any more troubleshooting of the chassis yet.

Bobby Brady · #11 07-02-2006, 02:37 PM

I sure am grateful for this info because I thought I heard a tube is simply gone if it has blue in it. Had it not been for this thread I would have instantly given up on such a tube.
I will be continuing to look for sets and it would be likely for me to get one someday.

Thanks guys you have likely saved more valuable CRT's!!!

bgadow · #12 07-03-2006, 12:17 PM

I had a CTC-31 with an intermittent in the video output which would kill the raster and give a bright blue neck. Apparently some voltage went missing when this happened.

superdeez · #13 07-15-2006, 11:09 PM

Could be a short or an arc in the tube. One time I fixed a friend's old TV when I found a brightener that effectively seperated the tube from the chassis. It could be switched between bright and normal, so it was just like a transformer operating at a 1:1 ratio.

It's pretty tobbacco road but it fixed the short and the set worked fine for another couple years before it got trashed in favour of a cheap plasma.