Thread: Too strange...
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Old 29-Sep-2011, 7:15 PM   #2
GroundUrMast
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Join Date: Oct 2010
Location: Greater Seattle Area
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Quote:
Originally Posted by Maury Markowitz View Post
...

I guess the grounding length was something close to 5/8ths of that frequency?
Quite unlikely... you also need to consider the length of wire in the wall.

The cover plate screw may be close enough to ground potential at DC and power line frequencies, but at VHF and higher, just a few inches changes the impedance of the wire. Achieving near zero ohm impedance connections at radio frequencies is quite challenging the moment you insert just a few inches of separation between two objects.

UHF channel 22 is 518 to 524 MHz. The wave length at that frequency is about 0.58 meters so, a 1/4 wave length would be only about 5 1/2".

WNLO, real channel 32 (virtual 23.n) is broadcast on even shorter wavelengths, 578 to 584 MHz (0.516 meters).

You've demonstrated the resilient nature of the forward error correction incorporated into the ATSC standard. Unlike analog NTSC signals that will have noise (snow) and multipath (ghosting effects) show in the display as the result of poor signal quality at the receive location, if you receive enough raw data so the receiver can recover the underlying data stream error free, the ATSC signal will display perfectly.
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Last edited by GroundUrMast; 29-Sep-2011 at 7:23 PM.
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