With 75 years of TV behind us, there is no clear fix for this. You'll get bars or stretch. There are plenty of old sets in shops across the country and Ebay so maybe the fix for you is to go back to CRT?
Bob
PS. http://www.tvhistory.tv/
The 10 year old 32" CRT TV died, so this is my first experience dealing with the black bars thing.
TV has OTA antenna connection. Scan got 13HD and 30 SD channels. The 13 HD channels are 16:9 no size settings needed. But the 30 SD channels are 4:3 with big side bars. Using the 'zoom' option fills the screen but makes the picture a 16:12 so top/bot portions of the picture are cut off, but picture can be moved up or down. Antenna is connected directly to TV to get local SD channels because as a DISH subscriber, they don't carry them.
A DISH 211K HD receiver is connected, but only SD service and using a HDMI cable. So between each channels sent signal, programming format and commercials, there's all kinds of different black bar scenarios.
The receiver options are different from antenna options.
16:9, 4:3, smart fit 1, smart fit 2, screen fit, wide fit.
Because I am basically receiving a 480 4:3 format, all settings have bars. 16:9 is stretch with top/bot/side bars, 4:3 is 4:3 with side bars, smart 1 & 2 make no sense as they reduce the picture by 50% and 75% with huge bars, screen fit does not function and has top/bot/side bars, clicking the 'expand' box does nothing. TV e-manual says that if a received signal is digital, this function is not available. I thought ALL signals are digital as required by the FCC for over 5 years. Wide fit- you get a 46" picture on a 48" screen, thin top/bot bars and slight wide stretch distortion because vertical is short WD HD channels. SD channels fill the screen. Some HD channels fill the screen according to what is being shown.
Disconnected HDMI and connected Component wires. Everything the same as HDMI, even picture quality. But here's something odd. Disconnected the component and connected old fashion RCA composite wires. The 'zoom' function that was grayed out became available and only a slight degradation of picture quality.
Being that 16:9 format is the only thing available, I think it's time for TV makers and TV signal senders to get together to adopt standard rules as to how a SD signal is processed to fit a 16:9 screen without bars and distortions.

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