That's dreadful news, after you had made so much progress with this unique set.

I suppose there's no sure way to predict or prevent such a failure. All the more reason to enjoy these sets while we can.

Regards,

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

I'm sorry to hear about that.. I'm going through nightmares myself with Picture Tubes..

How weird.

Even here in San Diego (no real extremes...just been a bit warm and humid).... I suddenly have "jeeees...this was fine last week" issues with the Sony 301 AND the Sony 305. Mine are simple instability issues. Not anything like this catastrophic thing :-(

So sorry to be reading this. It certainly was exciting to see color on it!

This is just so sad.... Sorry to hear! :(

jr

PS: a glass expert may be able to read the "ripples" in the crack and determine the starting point... just like ripples in a pond.

Right, the fracture can tell you a lot about how the failure manifested. I actually used to do a lot of that kind of thing in aviation, since I was part of an emergency reclamation team. It looks to me like it began right at the top where the heat was at its strongest, then propagated around the rest of the neck. I will send pictures to Filipe later this week, asking his opinion.

That's a darn shame, considering the effort put into the set.

On the other hand, if you had acquired her a year later you would have never made the progress that you did. One thing working in your favor is your relationship with RACS - I hope they can do something for you.

Ouch! What a terrible, random thing to have happen. It is so sad to see it happen to something so historic on top of that. I almost can't believe the news...it feels like only yesterday that I saw it come to life for the first time in ~60 years, and now this.:sigh:

I hope that the RACS repair idea is successful.

It could be the heat wave.....one of the replacement PS doubler caps I installed in my Silvertone roundy almost 2 years back went bad 11 days ago, and that was a fairly robust part! The year before I left the air conditioning off during vacation and returned to find one of the plastic feet on that same set had shattered despite the set being left otherwise undisturbed.

It might be a good idea to add some fans to the set if you ever get a good CRT in it again.

Life sucks sometimes.......

miniman,
What an unpredictable event this is. What could anyone do to prevent this tragedy?
Nothing I'm sure. It's a crummy outcome to a noble undertaking.

This is a very sad news... :sigh:

I've been following your progress, that is really a rotton event that should have never happened. Would have been great to see it to the end. I've got a CTC 10 and 11 and I really enjoy them to the fullest. Love the old Tv shows on them. I use both daily. Hope you can find a tube to at least keep it going. Good Luck.

Tom, Nick has been working with a CT-100 to power the prototype tube. I have his chassis in Ohio, and have been using a 15GP22 with it. Work will continue on the prototype chassis with a 15G, which will work just fine.

Damn shame. Best of luck with recovery efforts.

That crack in the neck of the CRT makes me wonder if it was thinner than later production tubes?

It's still a crying shame, though, that it went to air just after you got fairly decent color bars on it.

Bruce

What else could I say? Thanks for sharing what you have done.

So far I have had a 6GH8, 6JE6 and 21FJ crack and go to air after returning a retired set to service. None of these tubes were being touched, they just went to air while the set was off after I started using the set again.

I suppose Glass ages just like anything else, maybe after 50 or 60 years minor flaws become fatal flaws.

And I too have had tubes crack after lengthy power off. The CTC-9C that I have had a cracked audio output tube, I think, 6AQ5. Had a 7591 crack and give a really nice purple show as the air leaked in. Now THAT was an expensive tube...

I guess I've been lucky, I've never had a tube go to air. I've found a few in sets that I picked up but never while I've owned them. I better go knock on wood now. I just looked behind me and the CTC 11 that was dropped down the stairs is running in the living room. I use it every day....:rolleyes: I woke it up from a very long sleep.

I knew you would get that one going,Mark.

judging from the basket case 15g that RACS resurrected, I wouldn't think that this tube would be an issue since they would need to redo the neck of the tube to rebuild it in any event.

Isn't there a place in France that still rebuilds picture tubes? if so, I'm sure the shipping alone would be outstanding..

Yes, it's just a simple neck weld. The problem comes from the fact that if the planar dot plate and mask are heated at a different rate than the rest of the tube, the plate can crack or the mask can bend. This is the same issue as with the 15G, but it's worse because the prototype tubes have more thermal mass than a 15G does because its internal supports are heavier. This means even longer bake out times, and more cost. I've read notes from early books on the developmental tubes that state the face should be shielded during cooldown, to avoid cracking.

Just a reminder to all convention goers, Steve will be talking about the proto set this year and I assume there will be a demo of it working for all to see. Should be an interesting speech, hope I can be there to see it.

Heyboer Transformers 616-842-5830.they could you one from scratch if you had all of the specs on the power tranformer to run the set..ask for Phil...tell him i sent you..he could make you the filter choke(s) also if the specs on them also... Jody

I also endorse Heybour Transformer. Here's what I have for contact information:
http://i573.photobucket.com/albums/s...psaacb3245.png

What's all the hubbub about transformers?

I think someone confused the comments about the power supply chassis being missing. The problem is not a missing power transformer - we don't even have the schematic for the power supply chassis.

Then make one my friend,
Steve,... they've designed me one for 1927'Colonial 31 AC highboy console radio, that the power supply and speaker was missing
when i bought her,..he 's came up with the power transformer, chokes and audio transformers from using my schematic that I've got,...sent a copy to Phil and the rest is history,now you said you've got no schematic of it....what about you're having the voltages requirements and currents i.e.(milliamps) of the tubes and other goodies reqired to operate the set...you could get close enough to build it within 20 % tolenece of operating the set...have sheet metal fabber make up the missing chassis....just and idea!
Jody:yes::yes:

We did make a supply some time ago. See the report on restoration of this chassis:

http://www.earlytelevision.org/rca_cpa_restoration.html

Designing a power supply isn't rocket science, and we used transformers we had pulled from junk chassis.

The problem, however, was that we don't have a schematic for either the main or power supply chassis, and don't have documentation of the supply voltages. We had to guess and experiment to come up with what we think are the correct voltages.

i have never posted here before,despite being from australia i can definitely confirm that that the large male socket at the lower left side of the chassis goes down underneath to the power transformer on a small chassis which had 3 screw in fuse sockets a large tagstrip bolted to the rear on this particular set 4 black wires leading to the tagstrip had been altered and it was obvious this power tranny had 2 primary 110 volt windings which been reconnected for the 240vac mains voltage some local tv tech had bolted down a small 240 to 17volt transformer connected in a bucking configuration to reduce the mains from 240 to 220 approx this small transfomer looked like it had been intended for a 12volt battery and was also connected to the same tagstrip using spare unused tags this tv was bought for $15 in 1971 from the scrapguy at the local garbage tip in milperra ( a suburb of sydney) i remember him saying something like what do you want that old black and white monster for my sister who used to go to the tip to help my scavenge old 5valve radios and other interesting looking junk said to this guy that olt tv looks so cosmic compared to the other hmvs awa or pyes that were also awaiting there fate we used to routinely rob these sets of all the valves and sometimes the line o/p or flyback trans as i had some idea of trying to build a tesla coil anyhow we finally dragged this beast homeon a wheelbarrow bolted crudely to my bicycle as soon as my mother saw this she said havent you got enough electrical junk to play around with anyhow we finally got it into my sisters bedroom and swichted it on waited for a few minutes connected up aset or rabbits ears to the aerial panel turned the tuner knob numbered from 2 to 13 and could hear the locat channel atn 7 on the 8 position however there was no picture and the damper a 6au4 and the horizontal output valve had dull red glows after switching off i pulled the the top cap off the eht rectifier a 1b3 mounted at a weird angle and tried again same result then isaw this 1x2b and thought why should a tv have 2 eht rectifiers the penny didnt drop at that time however when this valve was pulled the line output stage immediately seemed more healthy ie arcs could be drawn from the top caps of both valves ithen went to my pile of junk and took a 1x2 out of alocally made awa p1 portable tv which had been junked because it had been dropped shattering the case and causing the crt to collapse inward fitting this 1x2 to the old tv still no picture but i followed the cable coming out from the socket and it found it was cracked where it passed over a support strut of the chassis once this was patched up by using about fifty turns of electrical tape finally sucess i found it could receive the four tv stations we had at that time but i never knew it was a colour tv till now the sound if had been retuned from 4.5mhz to 5.5mhz by somebody else long ago having seen this post i still wish ihad that old tv of course after i moved out my mother had one of cleanouts and you know where ALL my old radios tvs and other stuff went i give you one guess

Boora2,

Welcome.

All information is appreciated here, but if you could post in separate sentences and paragraphs, we would have an easier time understanding.

Hi All;
Since I just stumbled onto this posting just Yesterday, and it took till today to read thru it all..
First, let me say How sorry I am about the Picture Tube going to Air..
Are You going to continue to Test and Work on it Using a different Picture Tube ?? To See what the Engineers saw back in 1952 or so ??
Or is there No other Tube that You can use ??
THANK YOU Marty

WOW! What a post! Much good info, and an amazing run-on "paragraph", without even a period at what could be considered the end. Kind of reminds me of German compound nouns lol.
He got the info out, so I look forward to more posts from our new friend from Australia! :yes:

Geist, we continued to work on the chassis. Here is a page with info:
www.earlytelevision.org/rca_cpa_restoration.html

I will be giving a talk at the Early Television Convention on May 18 detailing the work. It will be live on the internet, check our home page on the 18th:

www.earlytelevision.org

Is the (prototype) set going to be at the convention? If so ... will it
be working?

Doug McDonald

Doug, yes it will be there and yes it will be working.

What is the nonsensical text at the bottom of some of the earlytelevision pages?

trojanrabbit,

That is what happens when someone who barely speaks English buys advertising. We get several hundred dollars a year from this advertiser, who insisted on that text. The links are to various test exams. I pointed out that the text makes no sense, but that is the way they wanted it.