Back in the old days manufacturers gave their sets names, this model is called "The Mayflower"
It's nicknamed a "Porthole" by collectors because the screen is not masked off in a 4:3 ratio but left open so the whole face of the picture tube is visible.
This allowed them to advertise more square inches of picture while still using the same 10 inch tube as everyone else.
It also requires either stretching the picture vertically so everyone is tall and skinny, or over scanning the whole image so you lose some image off the sides but the vertical is correct. I compromised here, the image is a little stretched vertically but it's also overscanned enough so Broderick Crawford doesn't look like Don Knotts.
Zeniths of this era are know for being difficult to restore, this one wasn't too bad except as is typical, the Flyback transformer was burned up, it was a weak point on these sets and you will run in to it often.
All the supplies of easily found old stock replacements have been used up so a bad fly is a showstopper, or at least that's what I thought.
It turns out the very common RCA Flyback used in nearly every other set of the late 40's can be made to work, it wires in directly with no circuit mods other than changing the capacitor inside the deflection yoke to eliminate some ringing in the image.
Other than the bad Fly restoration was pretty much normal, replacing all the capacitors and some resistors that had drifted out of spec.
The picture tube is a Rauland 10FP4 that tests like brand new.
The 10FP4 is the aluminized version of a 10BP4 and is resistant to Ion burns and also has a brighter picture with better contrast.
Typical of a vintage Zenith the picture on this set is amazing, very sharp and clear.
There is a socket on the back labeled "Phone Vision" this was an early Pay Per View type scheme created by Zenith, it apparently never got past the experimental stage.
Phone lines didn't have the bandwidth to handle the actual analog broadcast of a movie or event so they were used to send the sync signal needed to watch the program while the program itself was received over the air in the normal fashion, at least I think that's how it worked..
Note: There are Brass plated doors that cover the controls but they are flipped down in this video.
16 окт 2024
