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Crist Rigotti
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Post subject: Zenith H2447R 19" Porthole TV Posted: Oct Mon 23, 2017 2:27 am |
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Joined: Jan Sun 18, 2015 5:01 am Posts: 1429 Location: Waxahachie Texas
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Mr. Detrola
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Post subject: Re: Zenith H2447R 19" Porthole TV Posted: Oct Mon 23, 2017 3:13 am |
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Joined: Jan Thu 01, 1970 1:00 am Posts: 28021 Location: Detroit, MI USA
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That should be fine. I have seen plenty of older black and white CRT's that show a very watchable picture in the 100 to 200 microamp range, which is well down in the red area on a tester. Yours is quite a bit higher than that. Only way to find out for sure is see how it looks when the set is working properly. Worst case, you put a brightener on it while you look for a better one, but I think that will give a decent picture in a dimly lit room.
_________________ Dennis
Experience is what you gain when the results aren't what you were expecting.
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Notimetolooz
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Post subject: Re: Zenith H2447R 19" Porthole TV Posted: Oct Mon 23, 2017 3:16 am |
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Joined: May Thu 14, 2015 4:15 pm Posts: 1841 Location: Dallas, TX
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I agree with Mr. Detrola, give it a try.
_________________ Tim It's not the Destination, It's the Journey.
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aj2x
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Post subject: Re: Zenith H2447R 19" Porthole TV Posted: Oct Tue 24, 2017 12:47 am |
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Joined: Aug Thu 12, 2010 6:25 pm Posts: 297 Location: Durham, NC
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That is a nice-looking set. It's a model that accommodated the Zenith "Lazy Bones" remote control. That big shaft coming out of the back of that huge turret tuner took a drive chain or gear (I forget which) to the channel-change motor. The stylish little hand control at the end of 17-foot cable allowed you to move the channels up or down. Nothing more than that, though!
_________________ Mark Nelson A collector of TV signal boosters and UHF converters -- God help me! tv-boxes.com
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clsoca
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Post subject: Re: Zenith H2447R 19" Porthole TV Posted: Oct Wed 25, 2017 1:02 am |
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Joined: Jan Sat 16, 2016 10:03 pm Posts: 389
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A couple of my Zenith porthole CRTs (metal type like yours) tested bad/weak, (1 bad 1 Weak) and they illuminated just fine and keep on going with good contrast and brightness.
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Crist Rigotti
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Post subject: Re: Zenith H2447R 19" Porthole TV Posted: Nov Fri 03, 2017 3:52 am |
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Joined: Jan Sun 18, 2015 5:01 am Posts: 1429 Location: Waxahachie Texas
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Don Cavey
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Post subject: Re: Zenith H2447R 19" Porthole TV Posted: Nov Fri 03, 2017 1:55 pm |
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Joined: Jan Thu 01, 1970 1:00 am Posts: 14901 Location: Fernandina Beach, FL
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I think the important thing to consider is the proximity of the wire to the flyback. If it is the same distance as the original wire, I would thing that the voltage induced into the wire would be the same. But I am a hobbyist, not technician. Wait for others to chime in here...
_________________ Don
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Don Cavey
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Post subject: Re: Zenith H2447R 19" Porthole TV Posted: Nov Fri 03, 2017 1:56 pm |
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Joined: Jan Thu 01, 1970 1:00 am Posts: 14901 Location: Fernandina Beach, FL
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How about a piece of wire salvaged from a CRT type computer monitor? They should be plentiful.
_________________ Don
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Notimetolooz
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Post subject: Re: Zenith H2447R 19" Porthole TV Posted: Nov Fri 03, 2017 4:17 pm |
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Joined: May Thu 14, 2015 4:15 pm Posts: 1841 Location: Dallas, TX
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I don't think there would be any problem with replacing that filament wire with one with one with increased voltage ratings.
_________________ Tim It's not the Destination, It's the Journey.
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Crist Rigotti
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Post subject: Re: Zenith H2447R 19" Porthole TV Posted: Nov Fri 03, 2017 4:58 pm |
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Joined: Jan Sun 18, 2015 5:01 am Posts: 1429 Location: Waxahachie Texas
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Thanks guys for the comments. I have some 40Kv wire from an old TV that I'll use that is the same awg.
_________________ Crist
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Crist Rigotti
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Post subject: Re: Zenith H2447R 19" Porthole TV Posted: Nov Sat 04, 2017 6:02 pm |
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Joined: Jan Sun 18, 2015 5:01 am Posts: 1429 Location: Waxahachie Texas
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Crist Rigotti
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Post subject: Re: Zenith H2447R 19" Porthole TV Posted: Nov Sat 04, 2017 6:07 pm |
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Joined: Jan Sun 18, 2015 5:01 am Posts: 1429 Location: Waxahachie Texas
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Crist Rigotti
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Post subject: Re: Zenith H2447R 19" Porthole TV Posted: Nov Sat 04, 2017 6:08 pm |
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Joined: Jan Sun 18, 2015 5:01 am Posts: 1429 Location: Waxahachie Texas
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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.
Attachments: |

100_7827a.JPG [ 93.97 KiB | Viewed 3958 times ]
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_________________ Crist
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Crist Rigotti
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Post subject: Re: Zenith H2447R 19" Porthole TV Posted: Nov Sat 04, 2017 6:18 pm |
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Joined: Jan Sun 18, 2015 5:01 am Posts: 1429 Location: Waxahachie Texas
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Crist Rigotti
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Post subject: Re: Zenith H2447R 19" Porthole TV Posted: Nov Sat 04, 2017 7:54 pm |
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Joined: Jan Sun 18, 2015 5:01 am Posts: 1429 Location: Waxahachie Texas
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Notimetolooz
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Post subject: Re: Zenith H2447R 19" Porthole TV Posted: Nov Sat 04, 2017 9:04 pm |
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Joined: May Thu 14, 2015 4:15 pm Posts: 1841 Location: Dallas, TX
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Were there any paper tags on it before you washed it? I noticed you've got a great collection of test equipment there.
One caution about home kitchen convection ovens, the thermostats aren't very accurate and the temperature tends to "hunt". That means the temperature on small parts of low mass can get too hot briefly. Obviously you have things well in hand with yours.
_________________ Tim It's not the Destination, It's the Journey.
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Crist Rigotti
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Post subject: Re: Zenith H2447R 19" Porthole TV Posted: Nov Sat 04, 2017 10:54 pm |
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Joined: Jan Sun 18, 2015 5:01 am Posts: 1429 Location: Waxahachie Texas
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Notimetolooz wrote: Were there any paper tags on it before you washed it? I noticed you've got a great collection of test equipment there.
One caution about home kitchen convection ovens, the thermostats aren't very accurate and the temperature tends to "hunt". That means the temperature on small parts of low mass can get too hot briefly. Obviously you have things well in hand with yours. Good question on the tags. Yes, there were but I covered them up with wax paper and clear packing tape before the wash. I forgot to mention that. Yeah, ya gotta have 2 or 3 of each right? The chassis was put on the highest shelf possible in the oven because the heating element is on the bottom. 170 degrees was used because that's the lowest temp the oven could be set to. As a matter of fact, every few minutes I would turn off the oven, and then every 10 minutes I would turn it back on and so forth. It kept the chassis pretty warm but not warm enough to melt the wax off of the components.
_________________ Crist
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Notimetolooz
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Post subject: Re: Zenith H2447R 19" Porthole TV Posted: Nov Sun 05, 2017 1:40 am |
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Joined: May Thu 14, 2015 4:15 pm Posts: 1841 Location: Dallas, TX
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When I was a lad, my younger brother had a plastic model that he had painted. For some reason the paint wasn't drying like it should. I had the idea of putting the oven on its lowest setting to dry the paint. It didn't melt the plastic but when we opened the oven it looked like a caricature of an airplane. Must of stress relieved the plastic. I don't think he ever forgave me for my bright idea. Much more recently, out of curiosity I put a fine thermocouple in my oven. I don't remember exactly but the temperature variation was huge as the heating element went on and off, maybe a 50 degree swing! That would of been the air temperature, a solid object would have smoothed out the swing some.
_________________ Tim It's not the Destination, It's the Journey.
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clsoca
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Post subject: Re: Zenith H2447R 19" Porthole TV Posted: Nov Sun 05, 2017 5:20 pm |
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Joined: Jan Sat 16, 2016 10:03 pm Posts: 389
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Nice project. A I know I will learn a few things from your project here. I wanted to warn you about the fine tuning shaft inside the tuner. They are prone to break easily. Every time I tried to restring one it snapped in half at the pulley. No-matter how careful and gentle I was, they all snapped. Its made of some odd material that seems to weaken with the passage of time. I've fabricated a few replacement shafts using a wood dowel as the shaft material and never had a problem with any of them. I also try to use a belt instead of restring if I have one in my stash. It looks like yours does not require restringing. But just in-case, be aware. Attachment:
23G24 Wood Shaft.jpg [ 99.43 KiB | Viewed 3896 times ]
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Crist Rigotti
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Post subject: Re: Zenith H2447R 19" Porthole TV Posted: Nov Sun 05, 2017 5:44 pm |
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Joined: Jan Sun 18, 2015 5:01 am Posts: 1429 Location: Waxahachie Texas
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clsoca wrote: Nice project. A I know I will learn a few things from your project here. I wanted to warn you about the fine tuning shaft inside the tuner. They are prone to break easily. Every time I tried to restring one it snapped in half at the pulley. No-matter how careful and gentle I was, they all snapped. Its made of some odd material that seems to weaken with the passage of time. I've fabricated a few replacement shafts using a wood dowel as the shaft material and never had a problem with any of them. I also try to use a belt instead of restring if I have one in my stash. It looks like yours does not require restringing. But just in-case, be aware. Attachment: 23G24 Wood Shaft.jpg Thanks for the information. However mine has already snapped at the pivot point. I'll be doing a post on the repair later. The original material is Phenolic.
_________________ Crist
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