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Old 10-May-2019, 2:40 AM   #21
Retired A/V Tech
Join Date: Aug 2012
Location: S.E. VA
Posts: 2,717
Originally Posted by OTAFAN View Post
So, if I'm reading your chart correctly rabbit73, obviously you can have a higher noise floor on VHF low particularly, and still receive a watchable signal than either VHF high or UHF? And almost the opposite for UHF?
You almost have it right. Since the noise level IS higher on VHF, you must have a stronger signal on VHF than UHF to have an SNR of at least 15 dB above the noise.

One of the problems with VHF-Low reception of digital TV signals is that the FCC didn't allow enough extra transmitter power to overcome the higher noise level for reliable reception.
Forgive my learning curve rabbit73. When I became a shortwave enthusiast years ago, the first thing I learned was as long as I get above the noise floor with my receiver, antenna setup etc., I could "catch" the signal I was looking for. And the quieter my noise floor the better for weak signal reception.

I presume similar for TV viewing? Thanks!
That is correct.
If you can not measure it, you can not improve it.
Lord Kelvin, 1883

Last edited by rabbit73; 10-May-2019 at 2:49 AM.
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