Forums :: Resources :: Features :: Photo Gallery :: Vintage Radio Shows :: Archives :: Books
Support This Site: Contributors :: Advertise


It is currently Feb Sun 17, 2019 2:27 am


All times are UTC [ DST ]





Post New Topic Post Reply  [ 107 posts ]  Go to page Previous  1, 2, 3, 4, 5, 6  Next
Author Message
 Post subject: Re: Zenith H2447R 19" Porthole TV
PostPosted: Nov Sun 12, 2017 10:58 pm 
Member

Joined: Jan Sun 18, 2015 5:01 am
Posts: 1324
Location: Waxahachie Texas
cwmoser wrote:
Though I'm not currently working on a TV project, I do find what you are posting
very informative. You most likely have a lot of us reading your posts.
Impressive restoration work you are doing.


Thank you.

_________________
Crist


Top
 Profile  
 
 Post subject: Re: Zenith H2447R 19" Porthole TV
PostPosted: Nov Sun 12, 2017 10:59 pm 
Member

Joined: Jan Sun 18, 2015 5:01 am
Posts: 1324
Location: Waxahachie Texas
When I recap a chassis, I usually replace the resistors, and mica caps too. I get my 1W resistors from Mouser and they only cost 4 cents each, so I change them out. Of the past chassis I've done I see that at least 50% of the resistors are out of tolerance, 25% are very close, and 25% are within tolerance.

I'll cover what I do on a terminal strip. Tube sockets are treated the same. The first thing I do is take several pictures of the terminal strip. Then I draw out the terminals and what is connected to them. I also add where the other end is terminated. I then double check my drawing.

I then cut off the components and leave about 1/4 long leads still attached to the terminals. Then I use my solder sucker and solder wick, I clean off the terminal and remove the cut off leads. Then if a wire/wires are attached to the terminal, I clean it up and put the wire as far down the terminal as possible. I trim the leads to wrap around the terminal but not long enough to go back over the hole in the terminal. This keeps the hole opened up for additional components. When the wire/wires are set on the terminal, I then solder them to the terminal using as little solder as possible. I do this to be sure that the wire/wires are soldered to the terminal because when components are added and with the wire/wires being down low, they might be missed when adding solder. Also this small amount of solder holds the wire in place.

I then try to add the components in a logical manner. Once the terminal is fully populated, I solder it and then clean off the flux with an acid brush cut down to about 1/4 to 3/8 inch and acetone.


Attachments:
100_8106a.JPG
100_8106a.JPG [ 108.29 KiB | Viewed 2068 times ]
100_8107a.JPG
100_8107a.JPG [ 93.59 KiB | Viewed 2068 times ]
100_8109a.JPG
100_8109a.JPG [ 110.18 KiB | Viewed 2068 times ]

_________________
Crist
Top
 Profile  
 
 Post subject: Re: Zenith H2447R 19" Porthole TV
PostPosted: Nov Mon 13, 2017 4:26 am 
Member

Joined: Jan Sun 18, 2015 5:01 am
Posts: 1324
Location: Waxahachie Texas
I did a terminal strip located near the front of the chassis. It was pretty much self contained and consisted of just a few parts.


Attachments:
100_8111a.JPG
100_8111a.JPG [ 94.44 KiB | Viewed 2053 times ]
File comment: During the removal of the old parts, I noticed that there was that yellow CAD plating residue on parts of the terminal strip.
100_8113a.JPG
100_8113a.JPG [ 94.55 KiB | Viewed 2053 times ]
100_8115a.JPG
100_8115a.JPG [ 92.79 KiB | Viewed 2053 times ]
File comment: What I do to clean off that residue is I use CLR cut 50/50 with water. I brushed on a little with a cut down acid brush to about 1/2 inch long. I then "scrub" the area with the acid brush. Then I mop up the area with paper towels, Q-Tips, and alcohol. The residue comes off very easy this way.
100_8117a.JPG
100_8117a.JPG [ 95.91 KiB | Viewed 2053 times ]
File comment: I then replaced the components and cleaned off the flux, and I'm done.

Since this picture was taken, I added some more solder to the lower ground terminal.

100_8122a.JPG
100_8122a.JPG [ 87.92 KiB | Viewed 2053 times ]

_________________
Crist
Top
 Profile  
 
 Post subject: Re: Zenith H2447R 19" Porthole TV
PostPosted: Nov Mon 13, 2017 12:52 pm 
Member
User avatar

Joined: Jan Thu 01, 1970 1:00 am
Posts: 3557
Location: Advance, NC USA
Your comment ...
"When I recap a chassis, I usually replace the resistors, and mica caps too. I get my 1W resistors from Mouser and they only cost 4 cents each, so I change them out. Of the past chassis I've done I see that at least 50% of the resistors are out of tolerance, 25% are very close, and 25% are within tolerance.

I'll cover what I do on a terminal strip. Tube sockets are treated the same. The first thing I do is take several pictures of the terminal strip. Then I draw out the terminals and what is connected to them. I also add where the other end is terminated. I then double check my drawing.

I then cut off the components and leave about 1/4 long leads still attached to the terminals. Then I use my solder sucker and solder wick, I clean off the terminal and remove the cut off leads. Then if a wire/wires are attached to the terminal, I clean it up and put the wire as far down the terminal as possible. I trim the leads to wrap around the terminal but not long enough to go back over the hole in the terminal. This keeps the hole opened up for additional components. When the wire/wires are set on the terminal, I then solder them to the terminal using as little solder as possible. I do this to be sure that the wire/wires are soldered to the terminal because when components are added and with the wire/wires being down low, they might be missed when adding solder. Also this small amount of solder holds the wire in place."

... Sounds time consuming but I think in the long run it saves lot of troubleshooting and results in a better
restoration.
This is good advice for all of us experienced and especially novices who attempt to restore a
Television for the first time especially those that do not have great TV troubleshooting experience.
Basically its all about being methodical and learning more about electrical restoration.
Whats the moral to the story about the Tortoise and the Hare"?


Top
 Profile  
 
 Post subject: Re: Zenith H2447R 19" Porthole TV
PostPosted: Nov Mon 13, 2017 6:58 pm 
Member

Joined: Jan Sun 18, 2015 5:01 am
Posts: 1324
Location: Waxahachie Texas
Yeah, saves in a lot of troubleshooting and most importantly a better restoration.

_________________
Crist


Top
 Profile  
 
 Post subject: Re: Zenith H2447R 19" Porthole TV
PostPosted: Nov Mon 13, 2017 7:00 pm 
Member

Joined: Jan Sun 18, 2015 5:01 am
Posts: 1324
Location: Waxahachie Texas
Moving to the upper part of the chassis I decided to do the terminal strip near T3.
Pretty routine and nothing special to report except I had to lengthen a lead on R84 a 100 Ohm resistor. What I do is trim the one side to about 1/4 inch length. I then use some 22awg bus wire and attach it to the trimmed lead using the coil method. I then figure out how long the lead needs to be and slide a piece of 1/16 inch heat shrink tubing down to the coil. I then shrink the tubing and then use a 1/4 inch long piece of 1/8 heat shrink tubing to cover up the coil.


Attachments:
100_8123a.JPG
100_8123a.JPG [ 94.06 KiB | Viewed 2025 times ]
100_8131a.JPG
100_8131a.JPG [ 94.3 KiB | Viewed 2025 times ]
100_8127a.JPG
100_8127a.JPG [ 37.58 KiB | Viewed 2025 times ]
100_8128a.JPG
100_8128a.JPG [ 28.09 KiB | Viewed 2025 times ]

_________________
Crist
Top
 Profile  
 
 Post subject: Re: Zenith H2447R 19" Porthole TV
PostPosted: Nov Tue 14, 2017 6:21 am 
Member

Joined: Jan Sun 18, 2015 5:01 am
Posts: 1324
Location: Waxahachie Texas
Some more work around V9.
Then some around V14.
And finally an over all picture of my progress.


Attachments:
100_8133a.JPG
100_8133a.JPG [ 113.37 KiB | Viewed 1998 times ]
100_8139a.JPG
100_8139a.JPG [ 118.24 KiB | Viewed 1998 times ]
100_8145a.JPG
100_8145a.JPG [ 95.01 KiB | Viewed 1998 times ]
100_8148a.JPG
100_8148a.JPG [ 97.97 KiB | Viewed 1998 times ]
100_8151a.JPG
100_8151a.JPG [ 120.15 KiB | Viewed 1998 times ]

_________________
Crist
Top
 Profile  
 
 Post subject: Re: Zenith H2447R 19" Porthole TV
PostPosted: Nov Thu 16, 2017 4:41 am 
Member

Joined: Jan Sun 18, 2015 5:01 am
Posts: 1324
Location: Waxahachie Texas
My high voltage wire came in so I finished the Flyback wiring. I decided to use some new 20Kv 22awg wire. I've used this stuff before and it has worked well for me. The working H.V. is about 12 to 14Kv.
I used some heat shrink to increase the diameter of the wire and to provide some extra abrasion resistance as it passes through the then guides. I then soldered it to the 1B3GT tube socket and used several layers of heat shrink tubing to provide some extra strain relief on the wires as they go into the tube socket. I then used some lacing cord to tie the wires together before they go into the tube socket shell.

I also used some of this wire for the plate cap wire for both 6BQ6GT and the 1B3GT tubes. I'll terminate the CRT HV lead during the dry fit phase.


Attachments:
100_8165a.JPG
100_8165a.JPG [ 95.84 KiB | Viewed 1935 times ]
100_8168a.JPG
100_8168a.JPG [ 88.99 KiB | Viewed 1935 times ]
100_8169a.JPG
100_8169a.JPG [ 96.83 KiB | Viewed 1935 times ]
100_8172a.JPG
100_8172a.JPG [ 98.92 KiB | Viewed 1935 times ]
100_8174a.JPG
100_8174a.JPG [ 98.68 KiB | Viewed 1935 times ]

_________________
Crist
Top
 Profile  
 
 Post subject: Re: Zenith H2447R 19" Porthole TV
PostPosted: Nov Fri 17, 2017 2:57 am 
Member

Joined: Jan Sun 18, 2015 5:01 am
Posts: 1324
Location: Waxahachie Texas
OK guys, I have some questions for the disc capacitors in this TV. I know they should be good, but I tested one and it was 50% high. So I'm thinking that maybe I'll replace them. There are only 10 of them.
My question is what do I use to replace them? I know I need ceramic disc and I'm thinking of getting 1KV type. I know there are by-pass and coupling caps. Do I get COG, NPO, Z5U, Y5P, etc?
Below is a simple chart I made up that shows the SAMS parts list and the cross for each size cap. Also the Item Number of each cap. I checked the old Allied Catalog archive but they don't really list the specs for those caps.
Any help would be appreciated.


Attachments:
100_8184a.JPG
100_8184a.JPG [ 108.33 KiB | Viewed 1908 times ]

_________________
Crist
Top
 Profile  
 
 Post subject: Re: Zenith H2447R 19" Porthole TV
PostPosted: Nov Fri 17, 2017 4:32 am 
Member

Joined: Jan Sun 18, 2015 5:01 am
Posts: 1324
Location: Waxahachie Texas
I have finished the main chassis except for the IF Strip.
We, the VRPS of Dallas, has our annual convention this weekend so there will be very little work and posting on my progress.


Attachments:
100_8188a.JPG
100_8188a.JPG [ 159.59 KiB | Viewed 1894 times ]

_________________
Crist
Top
 Profile  
 
 Post subject: Re: Zenith H2447R 19" Porthole TV
PostPosted: Nov Fri 17, 2017 4:34 am 
Member
User avatar

Joined: Mar Sun 01, 2009 10:27 pm
Posts: 4829
Location: Ann Arbor, MI
Crist Rigotti wrote:
OK guys, I have some questions for the disc capacitors in this TV. I know they should be good, but I tested one and it was 50% high.

That is quite likely within spec for a ceramic cap. Some common tolerances are -20%,+40% -20%,+50% -20%,+80% -0%,+100%

Crist Rigotti wrote:
So I'm thinking that maybe I'll replace them. There are only 10 of them.
My question is what do I use to replace them? I know I need ceramic disc and I'm thinking of getting 1KV type. I know there are by-pass and coupling caps. Do I get COG, NPO, Z5U, Y5P, etc?


Both COG & NPO mean that the capacitance should not vary much with temperature. That should be OK but probably not what was used. Z5U means a temperature range of +10 degrees C to +85 degrees C with a capacitance variation of -56% to +22% over that range. Y5P means a temperature range of -30 degrees C to +85 degrees C with a capacitance variation of Plus or minus 10%. Probably Y5P is the thing to use.

_________________
Tom


Top
 Profile  
 
 Post subject: Re: Zenith H2447R 19" Porthole TV
PostPosted: Nov Sat 18, 2017 12:03 am 
Member
User avatar

Joined: Aug Thu 12, 2010 6:25 pm
Posts: 216
Location: Durham, NC
That Y5P rating would certainly be better than anything they originally installed for bypass caps.

_________________
Mark Nelson
A collector of TV signal boosters and UHF converters -- God help me!
tv-boxes.com


Top
 Profile  
 
 Post subject: Re: Zenith H2447R 19" Porthole TV
PostPosted: Nov Tue 21, 2017 6:35 am 
Member

Joined: Jan Sun 18, 2015 5:01 am
Posts: 1324
Location: Waxahachie Texas
Thanks guys for that info on the disc caps.

_________________
Crist


Top
 Profile  
 
 Post subject: Re: Zenith H2447R 19" Porthole TV
PostPosted: Nov Tue 21, 2017 6:36 am 
Member

Joined: Jan Sun 18, 2015 5:01 am
Posts: 1324
Location: Waxahachie Texas
During this weekend swap meet at our annual convention, I managed to get a few "donor" E-Caps for C4. This E-Cap is the smaller diameter kind.
I restuffed it basically the same way as the others. I use some R/C wing tube that I had after building a model. This stuff works great. I kept the caps out of the sleeve because they put a slight pressure on the sleeve and I thought it would deform the round sleeve. I haven't cleaned out the cans yet.


Attachments:
100_8232a.JPG
100_8232a.JPG [ 71.96 KiB | Viewed 1807 times ]
100_8231a.JPG
100_8231a.JPG [ 88.63 KiB | Viewed 1807 times ]
100_8230a.JPG
100_8230a.JPG [ 64.66 KiB | Viewed 1807 times ]
100_8235a.JPG
100_8235a.JPG [ 76.7 KiB | Viewed 1807 times ]
100_8236a.JPG
100_8236a.JPG [ 88.61 KiB | Viewed 1807 times ]

_________________
Crist
Top
 Profile  
 
 Post subject: Re: Zenith H2447R 19" Porthole TV
PostPosted: Nov Wed 22, 2017 5:28 am 
Member

Joined: Jan Sun 18, 2015 5:01 am
Posts: 1324
Location: Waxahachie Texas
The bottom side of the chassis is done. Every resistor, film cap, electrolytic, disc, and mica cap was replaced. Now on to the topside. The HV cage, tuner, yoke, etc.


Attachments:
100_8249a.JPG
100_8249a.JPG [ 128.33 KiB | Viewed 1783 times ]

_________________
Crist
Top
 Profile  
 
 Post subject: Re: Zenith H2447R 19" Porthole TV
PostPosted: Nov Thu 23, 2017 12:00 am 
Member

Joined: Jan Sun 18, 2015 5:01 am
Posts: 1324
Location: Waxahachie Texas
I replaced all of the resistors in the tuner today. 3 of them were a bit tough. I relied on the coil method for those 3 and a few other places. I cleaned the tuner assembly and then replaced the resistors. I then used De-Oxit and a business card to clean the fingers where the tuning strips slide through.

As a side note the average the resistors were 23% from their nominal resistance. The lowest was 3% and the highest was 62%. Of the 9 resistors replaced, 5 were way out of tolerance, 2 were 12% (just out of tolerance), and 2 were 3% (well within tolerance). Pretty close to what I've seen through the 6 chassis I've restored. Where at least 50% were out of tolerance. 25% were just out of tolerance, and 25% were with in tolerance.


Attachments:
100_7984a.JPG
100_7984a.JPG [ 95.57 KiB | Viewed 1760 times ]
100_7983a.JPG
100_7983a.JPG [ 96.29 KiB | Viewed 1760 times ]
100_8284a.JPG
100_8284a.JPG [ 92.97 KiB | Viewed 1760 times ]
100_8291a.JPG
100_8291a.JPG [ 92.87 KiB | Viewed 1760 times ]
100_8002a.JPG
100_8002a.JPG [ 83.13 KiB | Viewed 1760 times ]

_________________
Crist
Top
 Profile  
 
 Post subject: Re: Zenith H2447R 19" Porthole TV
PostPosted: Nov Sat 25, 2017 1:06 am 
Member

Joined: Jan Sun 18, 2015 5:01 am
Posts: 1324
Location: Waxahachie Texas
On to the turret. This turret is massive and very well built. First a photo 'walk around".


Attachments:
File comment: Here it is just removed from the chassis with the outboard cover removed.
100_8294a.JPG
100_8294a.JPG [ 89.27 KiB | Viewed 1712 times ]
File comment: The aft (motor driven end), if so equipped.
100_8295a.JPG
100_8295a.JPG [ 91.76 KiB | Viewed 1712 times ]
File comment: Looking at the side that faces to picture tube.
100_8296a.JPG
100_8296a.JPG [ 95.88 KiB | Viewed 1712 times ]
File comment: This is the side that faces forward. It also has the oscillator adjustment tool and drive gear.
100_8297a.JPG
100_8297a.JPG [ 91.54 KiB | Viewed 1712 times ]
File comment: Close up of the front end.
100_8298a.JPG
100_8298a.JPG [ 96.08 KiB | Viewed 1712 times ]

_________________
Crist
Top
 Profile  
 
 Post subject: Re: Zenith H2447R 19" Porthole TV
PostPosted: Nov Sat 25, 2017 1:13 am 
Member

Joined: Jan Sun 18, 2015 5:01 am
Posts: 1324
Location: Waxahachie Texas
More turret pictures.


Attachments:
File comment: A close up of the detent mechanism. Another indication of the quality of this TV.
100_8302a.JPG
100_8302a.JPG [ 87.86 KiB | Viewed 1712 times ]
File comment: The aft end ball race adjuster. The turret is suspended by 2 ball bearings. The front end uses a race and 9 "free range" ball bearings, while the aft end uses a thrust bearing. The aft end race can be adjusted in or out to get all the "play" out yet still spin freely.
100_8304a.JPG
100_8304a.JPG [ 85.05 KiB | Viewed 1712 times ]
File comment: The front end race.
100_8303a.JPG
100_8303a.JPG [ 98.95 KiB | Viewed 1712 times ]
File comment: The aft thrust bearing and the 9 balls for the front race.
100_8305a.JPG
100_8305a.JPG [ 93.78 KiB | Viewed 1712 times ]
File comment: A close up of the front shaft where the balls ride.
100_8306a.JPG
100_8306a.JPG [ 97.24 KiB | Viewed 1712 times ]
File comment: A close up of the aft section where the thrust bearing rides.
100_8307a.JPG
100_8307a.JPG [ 92.01 KiB | Viewed 1712 times ]
File comment: I took this picture to "locate" the actual strip according to the number stamped into the turret.
100_8311a.JPG
100_8311a.JPG [ 95.67 KiB | Viewed 1712 times ]

_________________
Crist
Top
 Profile  
 
 Post subject: Re: Zenith H2447R 19" Porthole TV
PostPosted: Nov Sat 25, 2017 1:17 am 
Member

Joined: Jan Sun 18, 2015 5:01 am
Posts: 1324
Location: Waxahachie Texas
I removed each strip and then I cleaned all the parts and removed some light rust from the inside of the cage. The strips will be dealt with later.
The turret is copper plated steel and while cleaning and polishing it, I rubbed through the plating. My idea was to clear coat the polished copper plated turret to prevent it from tarnishing. Then I remembered that I had some Rust-Oleum Metalic Copper spray paint. A couple of quick coats and we are in business.


Attachments:
File comment: Here is a picture of the aft end where I masked off the thrust bearing race and the new paint. Not much difference. The turret looks very good painted.
100_8317a.JPG
100_8317a.JPG [ 85.7 KiB | Viewed 1712 times ]
File comment: Here is a picture of the turret installed into the cage and the free end play adjusted along with the drive gear installed. The turret spins very nicely with no end play.
100_8347a.JPG
100_8347a.JPG [ 91.84 KiB | Viewed 1712 times ]
File comment: The end play is taken up by screwing in on the aft ball race. When adjusted just right, the large nut is then tightened to "lock" the assembly. While this might lock the assembly, there was some greenish looking liquid applied to the lock nut and race to prevent it from coming loose. I used some Super Corona Dope that I had to lock the assembly down.
100_8352a.JPG
100_8352a.JPG [ 95.84 KiB | Viewed 1712 times ]
File comment: A close up of the front end after assembly.
100_8353a.JPG
100_8353a.JPG [ 83.76 KiB | Viewed 1712 times ]

_________________
Crist
Top
 Profile  
 
 Post subject: Re: Zenith H2447R 19" Porthole TV
PostPosted: Nov Sat 25, 2017 3:53 am 
Member
User avatar

Joined: Mar Sun 01, 2009 10:27 pm
Posts: 4829
Location: Ann Arbor, MI
Looking at the numbers on the end of the turret, it looks like the channel strips are arranged every other channel starting at 2 and then after 13 start over again with 3. Yet the channel selector knob shows the numbers in order. How does this work?

Locktite makes something called thread locker. But that is not what would have been used in this set. I also seem to remember that there was something called glyptol. But I think that that was red.

_________________
Tom


Top
 Profile  
 
Post New Topic Post Reply  [ 107 posts ]  Moderators: 7jp4-guy, Mr. Detrola Go to page Previous  1, 2, 3, 4, 5, 6  Next

All times are UTC [ DST ]


Who is online

Users browsing this forum: Google [Bot], philsoldradios and 2 guests



Search for:
Jump to:  


























Privacy Policy :: Powered by phpBB