How much to offer for RCA w/doors?

[radiotvnut]

Originally Posted by ggregg

It works but is quite weak. I have a tester/rejuvenator on the way. We will see if it's past the point of no return or not. The Predicta has a bright CRT and a good fly so I bought it for that. But eventually I will have to get into the board. Not really looking forward to it after all I've heard, but I always wanted one and now I do.

What kind of Rejuvenator did you get? Most models from the mid '70's on were decent at rejuvenating a CRT. The older rejuvenators did a good job of cleaning the crud, as well as any emitting material, from the cathode.

Before you rejuvenate the CRT, you might try letting it sit for a few hours with around 8 volts on the filament. Old tubes will often become weak from sitting unused for decades and the elevated filament voltage will often bring them back up.

[ggregg]

B&K CRT model 400. I didn't research it or anything so I don't know if it's any good or not. Just bid the opening bid on a whim and got it for about $15.00 including shipping. It has shipped so we will see what I have when it gets here.

[radiotvnut]

That's a very old one from the '50's. It will check your tube OK; but, I wouldn't use the rejuvenate function. And, it's likely that this tester will need an overhaul before it will give accurate results. B&K didn't make a good rejuvenator until the model 467 and continuing through the model 490.

[Kevin Kuehn]

I have a B&K 466 that seems to work ok, I've rejuvenated a couple tubes succesfully with it. Now I'm curious what shops used back in the 50's to get the job done, or did they only sell new or rebuilt tubes when they got weak?

Kevin

[radiotvnut]

Originally Posted by Kevin Kuehn

I have a B&K 466 that seems to work ok, I've rejuvenated a couple tubes succesfully with it. Now I'm curious what shops used back in the 50's to get the job done, or did they only sell new or rebuilt tubes when they got weak?

Kevin

I knew a guy who ran a TV/radio service shop from the late '40's until 1973. He once told me that he used various B&K models, including the popular blue cased 465. He said that when he ran into a weak tube, he would try to talk the customer into buying a new tube (assuming the TV was worth a new tube). He would also add that there was a chance that he could rejuvenate the old tube; but, chances were good that it wouldn't last long and there was a chance that rejuvenation might make the tube look worse than before. If the customer didn't want to spring for a new CRT and if they were willing to take a chance, he'd rejuvenate the tube. He said that the results varied from making the tube brighter for a few hours up to a few months. And, there were those tubes that rejuvenation either didn't help at all or made them worse. If the customer later wanted a new CRT, he would apply the rejuvenation cost towards a new tube.

My first CRT tester was a B&K 465 that had three levels of cathode stripping (oops, I meant rejuvenation). On the lowest setting, I had some luck at bringing back weak B&W tubes. Usually, if the lowest setting didn't do it, you could forget it. And, I never had much luck with rejuvenating color tubes with this tester.

I think where a lot of shops made their mistake was thinking "more is better". Instead of starting out with the lowest form of rejuvenation possible, they'd flip the rejuvenator to "high" and end up burning up a tube that could have probably been saved had they used caution. Once, I loaned my 465 to a TV repairman friend, who didn't have a CRT tester at the time. He wanted to rejuvenate a '70's delta gun color tube. Despite my words of warning, he flipped the tester on the highest level of rejuvenation and pressed the rejuvenate button about 6 times. Needless to say, he ended up putting another tube in that set. When I rejuvenated a tube with this tester, I set it on the lowest form of rejuvenation and hit the button once, for a fraction of a second. Then, I'd recheck the emission level.

I'n the mid '90's, I bought a newer B&K 470 and I have rejuvenated all sorts of tubes with it. I'd say that it's helped 95% of the CRT's that needed rejuvenation and I don't think I've ever had a CRT that was worse after rejuvenation. The other 5% of the CRT's that it didn't help were usually either worn out or poor quality ('90's era Zenith tubes) to begin with.

Even on the B&K 470, I start out using the "clean and balance" function. Usually, this will do the trick. If it does not, I move to the rejuvenate function. And, I can usually tell if the CRT will hold up or not by how long the meter pointer stays up. When I press the rejuvenate button, if the meter rises a small amount and immediately falls back down, the CRT probably won't hold up. If the pointer rises towards the middle or top of the scale and stays there for several seconds before slowly dropping back down, the tube will probably hold up.

[ggregg]

Very good information. Thanks.

[Kevin Kuehn]

Thanks for those details, very interesting.

Kevin

[JCFitz]

I got it.almost didn't though. When I offered $25 he started bringing up ebay prices.I was going to leave but I tried $50.He finally came up with $75.no way I was paying $75 but I said I might entertain more if you let me test a few things.Since he had plugged it in I decided to give it a whirl.It came up with a raster.So the flyback was proven good and the crt had life.But I wanted to see how much so I brought in my B&K 465.It was a little slow getting there(around a couple of minutes) but the emission came up well into the good range at near 700 without boosting the fliament or anything.So my final offer was $60 and if he didn't say yes I was ready to walk away even though I had just drove over 50 miles to Trappe MD. He said yes so it's mine.

Btw it is a RCA model 17T172 chassis I believe is a KCs 66.It's double stamped and hard to read. It has been converted to a larger tube a 20" but the replacement bezel doesn't look bad at all. you can just put your finger under the middle of it on the 4 sides. I told him that but he probably wouldn't have heard or paid attention to this being a reason it was worth less. Oh well.Probably paid too much but it will get saved now instead of wasting away in that garage,going to the dump or being turned into a fish tank or bar.

[jeyurkon]

IMHO I don't think you paid too much. When you look at what you'd pay for a good CRT if you needed one.

A lot of TVs and radios are being parted out because it's a lot more profitable to sell them in pieces than as a working unit.
John

[radiotvnut]

Glad you got it and I hope you get it working! The CRT being good is a big plus! I can't say what I would have done had I been in your shoes when he brought ebay prices into the mix. Had it been local to me, I would have told him to go ahead and sell it on ebay. The fact is, had he listed that set on ebay, he probably would not have gotten anything for it unless someone was close enough to pick it up in person. I just get so darn sick and tired of everyone bringing up what they sell for, or what someone is asking, on ebay.

[Eric H]

$60 isn't bad at all if you like the set.
I paid exactly the same for my 1953 Philco ten years ago and I knew it had a weak CRT, I bought it because it was really clean and I knew it would wind up a Fish Tank if I didn't.
I got it all working though and don't regret buying it one bit!

The CRT size upgrade is kind of interesting actually, is it a Factory kit or home brewed?

[ggregg]

Nice set. Good for you. HV and a good CRT are huge pluses.

[JCFitz]

Originally Posted by Eric H

$60 isn't bad at all if you like the set.
I paid exactly the same for my 1953 Philco ten years ago and I knew it had a weak CRT, I bought it because it was really clean and I knew it would wind up a Fish Tank if I didn't.
I got it all working though and don't regret buying it one bit!

The CRT size upgrade is kind of interesting actually, is it a Factory kit or home brewed?

I dunno about the upgrade. If it is homebrew they did a pretty neat job of it. The main giveaway is that the crt comes out the front enough that there's a gap in the middle of the mask on all 4 sides you can stick your finger under. It is flush at the corners and is screwed to the cabinet with a screw at each corner.Doesn't look bad at all.

[dieseljeep]

Originally Posted by JCFitz

I dunno about the upgrade. If it is homebrew they did a pretty neat job of it. The main giveaway is that the crt comes out the front enough that there's a gap in the middle of the mask on all 4 sides you can stick your finger under. It is flush at the corners and is screwed to the cabinet with a screw at each corner.Doesn't look bad at all.

According to the picture, the set's in very good condition. It's a pretty large cabinet for a 17" set. There was a firm that made conversion kits for installing larger CRT's in smaller screen sets. It probably had a 17CP4 that went bad early in the set's life.

[JCFitz]

The original tube was a 17GP4 It has been replaced with a 20CP4 along with the required focus magnet.Kinda looks homebrew from the rear. It is a RCA 20CP4. The hole was cut wider for the crt on the sides and there is a single piece of 1" thick board supporting it at the front. Anyhow it works.

I made the mistake of firing it up again to see if I could get a signal through it with a digital converter box.One of the filters started to let go and I quickly pulled the plug.It won't get turned on again until it gets the recap treatment.