Zenith H2447R 19" Porthole TV
I just got this this weekend.
http://i1060.photobucket.com/albums/...psilp7dijs.jpg http://i1060.photobucket.com/albums/...pslgnfkinm.jpg http://i1060.photobucket.com/albums/...pspb7u9rig.jpg I tested the 19AP4 CRT and after cooking it awhile and doing a Clean on it using my BK 467 CRT tester, the CRT did come to life but just in the green. This picture shows the condition with 6.3V filament. http://i1060.photobucket.com/albums/...ps0gjmjd9y.jpg This picture shows the filament at 7V. http://i1060.photobucket.com/albums/...pspbmaz233.jpg Do you think I need another CRT? Let me know. |
Recap the chassis and do a normal restoration. The jug will more than likely produce an image, just not a super bright one.
I've seen dead looking B/W CRTs produce a nice, focused, fairly bright picture. The best CRT tester is a working chassis. If you do need a CRT, a 19AP4 isn't terribly hard to find. |
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That's a classic vintage TV by the way. Nice score! I've loved that model ever since a kid seeing it in the Stooges "Census Takers" episode. |
Nice find Christ, and to have a working 19AP4.:thmbsp:
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Thanks guys for the comments. I'm very happy I got it. The cabinet is in very nice shape and the chassis is too. I'll do the restore and then see how the 19AP4 looks. I like the brightener idea too.
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I've got a dual chassis 16" IIRC 24H20 porthole. CRT was stone dead and Nick and Mark hit it with a CR-70 rejuvinator and got it up in to the mid to upper red, set is all original caps except for 4-5 papers that were swapped for maroon drops in the 60's or 70's...It somehow came to life with a reasonably bright picture in that state.
Aside form the weak flyback on some portholes these sets are indestructible. |
These things ABSOLUTELY Blow the minds of yr typical smart alec teenager...Its almost worth the money for what one costs just to see the reactions they cause...
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Another thing to keep in mind: sometimes these tubes were last used 60+ years ago and have developed a very minor, and expected, case of cathode poisoning. The typical current draw of a tester is usually insufficient to bring the tube back up. Either forcing the tube to wake up via elevated heater voltage, cleaning it by pulling more current from the cathode a la the Beltron, running the tube on a working chassis with HV to clean up the cathode or some combination of the three is necessary to really get a tube working again.
My own two "dead" CRT stories: I won a 16AP4 at the ETF auction a few years ago that has been tested by some guy with a CR-7000. He wrote it off as a lost cause; it had low emissions and bad cutoff. I won it for $5 or $10, cleaned it on the Beltron. Now it tests like a brand new tube, has excellent cutoff, and is residing in a nice little Emerson producing a flawless image. The big Westy you just delivered for me looked poor on Beltron initially. Knowing I'd never find another 24AP4, I decided to bring the set up on a Variac. The tube is nice and bright, actually so bright it's irritating to look at. I retested it on the Beltron after unplugging the set and going away for the weekend. This morning it read right at the top of the scale with a 30ish second life test. It just needed a good "scrubbing" of the cathode and just running the set for 4 minutes or so must have been sufficient to clear up the cathode. Again, recap and run it. I think you likely have a good tube. |
Thanks for the good comments guys. I noticed that my BK 467 tester needs calibration on the filament scale. When the tester reads 6.3V, the CRT is only getting like 5.7V under load. I didn't check the filament reading with no load.
So when I cooked it at "7V" it was really close to 6.3V and I still got into the green. I'm thinking now especially after everybody's comments, the CRT will provide good service. Stay tuned for the restoration. |
Looking forward to watching this restore. :thmbsp:
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Wow, must have been port hole Sunday. Lol. I also picked one of these up on Sunday as well. Same exact set. My 19AP4 tests strong, but the chassis will still need some restoration. Found this set outside Gettysburg PA.
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You need to put these at the ends of the image location. [img] [/img]
https://tvrestorerguy.com/wp-content.../100_7684a.jpg |
These things are just SO uncompromisingly W31rd looking... NOT in a bad way, heavens no...
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He means take this
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What I was trying to say,& that obviously has gotten taken about as far out of context as possible is that these Porthole style sets were and are STRANGE looking-Especially now,as it seems that the normative "Look" for a TV is a black/grey rectangular plastic box w/little or no adornment at all. When Portholes were new, having a TV was still something of a big Deal, Zenith kinda run 'em up the flagpole,as the Sets with the "Giant CIRCLE screen", My Porthole is a12" tabletop model that is vinyl/leather covered. When I show it off, most people that are roughly my age-60 say they can remember them, but younger folks & kids are completely befuddled by it. Its also amazing as to how many people claim to never having seen A b/w TV of any sort...
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Zenith had a reputation of making strange looking radios too. Almost as if they were expecting future generations to collect them. ;)
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OK, here goes. I've started on the restoration of this TV. In the next few days or week I'll get caught up with the progress that I've made.
Fist off I'm working on the HV cage and Fly back. The FB coating was pretty melted and cracked. What I did to restore the FB will be part of the upcoming posts. What I'd like to show you guys and get opinions on is that the 1B3GT filament winding that is around the core of the FB might have an issue. The wire is held off the FB core with 2 thin pieces of a fiberglass like material. Where the filament winding has passed through those pieces, it looks like they "dug" into the insulation, thus compromising the insulation. Here are 2 pictures of the filament winding and how it is held in place around the FB: https://tvrestorerguy.com/wp-content.../100_7897a.jpg https://tvrestorerguy.com/wp-content.../100_7896a.jpg Now here is a close up of the damage to the insulation. It goes in some but not all the way to the conductor: https://tvrestorerguy.com/wp-content.../100_7920a.jpg I think I need to replace that wire. Now here is another question. If the original wire is lets say 20Kv and I use 40Kv wire, will there be enough "juice" to get through the "extra" insulation of the 30Kv wire to work the 1B3GT? |
"I think I need to replace that wire. Now here is another question. If the original wire is lets say 20Kv and I use 40Kv wire, will there be enough "juice" to get through the "extra" insulation of the 30Kv wire to work the 1B3GT?"
Sure, this is just a transformer with a one turn coil providing the 1.25 Volts for the 1B3 filament. Turns ratio is the only thing that counts here, extra insulation on the wire will not make any difference. jr |
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Uhh, now you've got sumpin even I never heard of...(Grin) STILL wish I could "Big Deal" a bunch of youse guys to come pay me a visit sometime next spring.. I'd take you to Sneedville,where they have this WILD commemorative to their War Dead.... Its a statue of a reputed Italian soldier... Seriously. They wanted to put up a statue to their War Dead, but they couldn't afford a NEW American one, so they bought a USED Italiano one..Hawk nose, handlebar 'Stache" holding a Carcano rifle, & a WTF-Am-I-doin'-HERE look on his face.. Most of you know that I'm a reasonably good Bullchip Artiste,but even I couldn't dream up anything to beat that..
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Guys, Lets stay on topic. thanks.
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I'm TRULY sorry that something I said got a bunch of y'all all upset & Discombobulated...THAT, of course, was/is never my intention.
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:) Exactly what I've done in the past in similar TV high voltage cage repairs , that's why I'm confident you'll have no problem with the wire's higher insulation rating . PS , I may not post all that much , but I've seen your restoration work and you do have great talent with making these old sets look great again ;) |
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You fellers who really know how to Work on this stuff are near Deities in my book.. I tried to learn enuf to maybe change out caps & resistors & stuff, but even THAT was beyond my 57 IQ abilities...
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Let's try and get caught up a little at least from the start.
After removing the chassis from the cabinet, I took many of the customary initial pictures of both the main and power supply chassis. I removed the tubes earlier when transporting the TV back home. I then removed the CRT. https://tvrestorerguy.com/wp-content.../100_7741a.jpg https://tvrestorerguy.com/wp-content.../100_7684a.jpg I then decided that this thing needs a bath. I went to the local "Quarter" car wash. Yup the local car wash. I used the "Presoak" setting to spray off both chassis on top and on the bottom. Then I used the "Ionised Water" to rinse them off. These settings at the car wash use a lot less pressure and with the wand 3 feet away, the car washing did an amazing good job of cleaning those chassis. Once back home I blew off the excess water with my blow gun set at 40 pounds. Then the chassis went into the oven set at 170 degrees F for several hours. Well worth the effort. https://tvrestorerguy.com/wp-content.../100_7751a.jpg https://tvrestorerguy.com/wp-content.../100_7696a.jpg |
I then wanted to check the "health" of the chassis by checking all the transformers and coils. All checked good even the nasty looking flyback except the H Hold coil L22 (Sams).
I removed the coil. https://tvrestorerguy.com/wp-content.../100_7785a.jpg I then unwrapped the black tape. Sure enough there was a broken wire. https://tvrestorerguy.com/wp-content.../100_7790a.jpg https://tvrestorerguy.com/wp-content.../100_7792a.jpg I was an easy repair to make. I unwound 1 turn and cleaned off the insulation and soldered it back on to the green terminal. If you look closely you can see the original wire underneath the white tape. https://tvrestorerguy.com/wp-content.../100_7793a.jpg I then used some black electrical tape to secure the wire. https://tvrestorerguy.com/wp-content.../100_7794a.jpg |
Then I labeled each component according to Sams 120-13. This is my usual practice. This helps me understand the chassis and the parts locations. When labeling the parts I checked their value against the parts lists. This readily points out what the differences are. Sure enough there were just a few. The Sams had a few typo errors and I also used Riders V6-1 to cross check both the Sams and Riders and the chassis. The biggest difference was R39 (located under L14) is listed as a 33K resistor wired to the 130V bus. This was what the picture shows to be in the Sams. But the chassis has a 75K resistor wired to the 360V bus. The Riders shows a 68K wired to the 360V bus. I'm thinking that perhaps a 68K 1W resistor was in short supply and a 75K was used on the assembly line. Most likely I'll use a 68K resistor.
Also you'll see that I removed several shafts from the front of the chassis to a pot and the tuner to have better access to the components. These will be cleaned before reinstallation. https://tvrestorerguy.com/wp-content...9757489865.jpg |
I removed the HV cage and disconnected the 4 wires going to the flyback.
https://tvrestorerguy.com/wp-content.../100_7893a.jpg https://tvrestorerguy.com/wp-content...00_7896a-1.jpg https://tvrestorerguy.com/wp-content.../100_7897a.jpg After removing the 1B3GT plate wire along with the 6BQ6GT plate wires and the door knob cap and 1B3GT socket I ohmed out the coils. They checked good. I then cleaned up the coils by removing the melted covering by chipping it off and using heat to melt it some. I used a lot of Q-Tips and acetone. I then cleaned off the yellowed cad plating and cleaned up the rest of the assembly. https://tvrestorerguy.com/wp-content.../100_7914a.jpg https://tvrestorerguy.com/wp-content.../100_7918a.jpg After cleaning I then baked the assembly at 225 degrees F for several hours. I then used my MG chemical Super Corona Dope and brushed on 4 coats. 1 coat on one side then bake for an hour, the do the other side and bake it again for an hour. This was repeated for 4 coats. The coils are just about filled and 2 or 3 more coats I'll be done. Stay tuned for the results. |
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