Zenith H2447R 19" Porthole TV

[Electronic M]

UHF channel strips were available for these tuners and IIRC were more common than UHF converters/outboard tuners with these sets. Watch a youtube video of an old Zenith film 'Fog Over Portland' for an interesting look at Zenith's UHF preparations.

[Crist Rigott]

Originally Posted by Electronic M

UHF channel strips were available for these tuners and IIRC were more common than UHF converters/outboard tuners with these sets. Watch a youtube video of an old Zenith film 'Fog Over Portland' for an interesting look at Zenith's UHF preparations.

Good video.

[Crist Rigott]

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.

[Crist Rigott]

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.

[Crist Rigott]

I installed the fly back and HV cage. No issues.

[Crist Rigott]

I replaced the 2 560 ohm yoke resistors and the 56pf 1Kv cap. I used a 56pf 3Kv COG disc cap. None of these 3 components were listed in the Sams parts lists but were listed in Riders.

[Crist Rigott]

Tomorrow I should be able to attach the yoke and focus coil wires. Then do my resistance check. Then if all is good, then the first power up.