Westinghouse H-223 restoration

[bandersen]

Originally Posted by Pio1980

How could RCA claim a patent on prior art, their superheterodyne downconversion claim notwithstanding?

I don't know the details but RCA definitely had TV patents.
Look on the back of most TVs and you'll see a label stating "Licensed under US patents of RCA"

You just need to convince the patent office that your application is different enough from any prior work. Plus, RCA was known for being very aggressive and screwing over the little guy.

[bandersen]

After fighting with the tuner and trying every channel, I finally got reception on channel #6.


Time to dig into the tuner.
WOW! What a trip. One of the coolest tuners I've ever seen
A beautiful piece of engineering!

The coils and caps are routed out of PCB type material. Similar to what you'd seen in modern RF electronics.






and here's the problem
There are score marks on the adjustments for channels 3 & 4 and the coils are damaged.
Likely a tool slipped while someone was trying to make adjustments.

I'll try to carefully push it back into place and glue down.

[nasadowsk]

Originally Posted by bandersen

I don't know the details but RCA definitely had TV patents.
Look on the back of most TVs and you'll see a label stating "Licensed under US patents of RCA"

Oddly, my CTC-4 also references patents from N.V Phillips. Be curious what that’s about…

You just need to convince the patent office that your application is different enough from any prior work. Plus, RCA was known for being very aggressive and screwing over the little guy.

RCA was known for screwing over everyone…

[DavGoodlin]

Originally Posted by bandersen

I was told Westinghosue and others didn't use a flyback to avoid paying royalties to RCA.

I'm working on a Sparton 4900, which uses a HV supply that is entirely separate from horizontal sweep also. 6SN7 connected as oscillator makes HV using a tubular coil, feeds a 1B3.

[DavGoodlin]

The Westinghouse Home Products division in Sunbury was over 70 miles from the nearest TV transmitter, on a flat spot at RR tracks and river north end of town.

WGAL-4 (later 8) was on a tall building in Lancaster. Philadelphia had three more channels but was over 100 miles, so maybe they tested the sets on top of the nearby hills.

That tuner is pretty interesting, I wonder if that distance alone affected their designs?

[dieseljeep]

Originally Posted by bandersen

I was told Westinghosue and others didn't use a flyback to avoid paying royalties to RCA.

That's gratitude for you!
Wasn't it a joint effort by GE and Westinghouse to form Radio Corporation of America!

[Pio1980]

Originally Posted by dieseljeep

That's gratitude for you!
Wasn't it a joint effort by GE and Westinghouse to form Radio Corporation of America!

American Marconi, General Electric, Westinghouse, and Wireless Specialty Apparatus Co. formed the Radio Corporation of America (RCA).

[Tom9589]

We had an old Hallicrafters that had a "similar" tuner. It was a turret design like a Standard Coil tuner except that the strips were actual printed circuit boards with the coils etched on the boards. Never had to clean this tuner. Must have done something right. It was about 50% larger than the Standard Coil tuner.

[dieseljeep]

Originally Posted by Tom9589

We had an old Hallicrafters that had a "similar" tuner. It was a turret design like a Standard Coil tuner except that the strips were actual printed circuit boards with the coils etched on the boards. Never had to clean this tuner. Must have done something right. It was about 50% larger than the Standard Coil tuner.

Way back in the early 50"s most smaller cities only had one channel, so the tuner didn't give trouble or need cleaning.

[Alex KL-1]

Originally Posted by Pio1980

I think I recall this set being desirable for the ability to change the scanning rates without affecting EHT crt voltage. Only one of two postwar magnetic deflection sets I recall that did not use flyback EHT, the other had a prewar brute force AC transformer source and one of the first post-war US production sets, don't recall make model.
Germany had at least one flyback EHT set ca 1939, the E-1 as a "peoples" television receiver.
https://www.earlytelevision.org/Etzold/e1-e.html

Very cool!
And some modern example exists, also: some hi-end and semi-hi-end monitor employed this same technique just for the multiscan. One example, the Sony F-99 chassis employs this.

[Alex KL-1]

Originally Posted by Electronic M

It would be interesting trying to get it to scan 720P or 1080i.

I think the same just when I read about... Tempting for the thinkerer... but very scary for owners, considering the rarity of these sets.
H circuits needs to be healty, since needs to reach 31500Hz just for 480p...

[dieseljeep]

Originally Posted by nasadowsk

Oddly, my CTC-4 also references patents from N.V Phillips. Be curious what that’s about…



RCA was known for screwing over everyone…

I read a pate

[dieseljeep]

Originally Posted by dieseljeep

I read a pate

I didn't finish the entry!
Anyway, this what I was going to enter!
I read a patent notice label on an RCA portable TV, mid 50's model. It mentioned, Motorola Inc. It must've meant the intercarrier sound IF.
RCA fought that for possibly 3 or 4 years of their early TV production.

[bandersen]

I carefully pushed the mangled coil back into shape and glued it down.


Success! I can now receive on both channels 3 & 4.

[bandersen]

Working on replacing the two multi-section twist locs now.
Even though they used twist-locs, there are existing mounting holes with the standing hole spacing for phenolic insulation wafers.
Perfect opportunity to use adapt-a-caps.


Ooops, slightly melted the wire insulation in a few spots
One down, one to go.

BTW those two 12K resistors in parallel is how it was originally built and shown on the schematic. Two 12K, 1W in parallel
I'm thinking 5.6K or 6.8K wasn't close enough?