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#1
11-25-2017, 03:42 PM
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Let's get those strips mounted and the assembly installed.
I mounted the cage to the main chassis and installed the "idler" gear. The idler gear was lubricated and bolted to the bracket, which was then screwed to the cage.  I then soldered on the wires removed when taking off the tuner assembly. Then the tuner was installed on top of the cage using the witness marks left when originally installed. I then screwed the first strip in place using the 2 4-40 screws and lock washers. I then carefully lined up the strip to the tuner and tightened the strip screws. This was repeated for all the rest of the strips.   I then carefully rotated the turret and could hear some fingers clicking rather than a nice wiping sound. There were 3 strips that made this noise. After careful examination I could see that these 3 strips were bowed up in the middle. I then bent the mounting ears on the turret down just a little bit using an adjustable wrench.  Remounted the strips and the problem was solved. I had a nice wiping sound on all the strips. I then applied some DE-Oxit to each side of each finger on each strip, then ran it through the tuner contacts. I did this twice to be sure I had clean contacts. I then installed the cover to protect those strips. 
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#2
11-25-2017, 03:49 PM
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The tuning shaft was the next item to be installed. I lubed the end that was nearest to the gear, and the channel selector knob shaft as it passed through the front of the chassis.
  I then aligned the turret with the channel selector by rotating the gear that attaches to the turret. I then tightened all the set screws and very lightly lubed the gears.
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#3
11-25-2017, 05:13 PM
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I installed the fly back and HV cage. No issues.
 
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#4
11-27-2017, 01:00 PM
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Looking great! I wish I had your patience!
Just curious... what is the ch number sequence of the strip placement and the ch number sequence of the indicator dial. From what I can see in the pix, it looks like the indicator dial is in numerical order but the strips are placed in a "most likely sequence for a given area" order. Scratching my head over how that works.  jr
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#5
11-28-2017, 08:14 PM
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Quote:
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#6
11-28-2017, 08:23 PM
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The resistance check so no errors.
I then powered it up with the rectifier tubes out. The filaments all glowed nicely. Then rectifier tubes in and I got B+ voltages. The high B+ reads 328V vs 360V and the lower B+ reads 186V vs 130v.  I have 11.5Kv and the picture looks washed out. All I've done so far is adjust the front controls. V Lin, V Size, Bright, Contrast, H Hold, V Hold, and the Buzz control on the back.  https://youtu.be/1U6SL5BV6-Y Any idea as to where to start? BTW, the test CRT is an 8YP4 with the adapter harness.
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#7
11-28-2017, 09:23 PM
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Possibly an open peaking coil in the video chain, somewhere 'upstream' of the sync take off point.
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#8
11-28-2017, 10:45 PM
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I just checked L15, L16, and L17 again. They all ohmed out good. See post #43 for the schematics.
Are there any more coils that I need to recheck?
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#10
11-29-2017, 10:16 AM
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It was the video detector diode. I replaced it with a 1N34A that I had.
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#11
11-29-2017, 04:51 PM
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Here is where I am using the original CRT that tested on the low side of good. All I've done is twiddle the front and back controls.
  I have another CRT that tests on the high side of good. I'll use this one for awhile during set up etc. I'm a happy camper.
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#12
11-29-2017, 07:16 PM
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Quote:
__________________
CW 1950 Zenith Porthole - "Lincoln"
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#13
12-03-2017, 07:53 AM
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I have had a bit of a set back. I was just starting to display a test pattern to adjust the picture when I heard a HV squeal coming from the HV cage. After some trouble shooting, it looks like the FB is the source. I'm going to have to replace the FB. I'm checking on the availability of one locally. ETF lists 2, 1 from 2 different manufacturers. The FB part numbers are:
Zenith = S17233 Thoradson = FLY-52 Merit = HVO-53 Stancor = A-8267 Triad = D-45 Ram = X070 ???? = HO-217
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#14
12-03-2017, 10:22 AM
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Before condemning the flyback verify the drive voltage at The output tube is good, AND that the oscillator frequency is correct. I've seen plenty of good flybacks make death squeals from the frequency being off...they also stop making HV when the frequency is off.
__________________
Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4
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#15
12-04-2017, 10:08 PM
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Quote:
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Hybrid Mode
