Quote:
Originally Posted by mtownsend
Ahh. It's clear now that there really is some terrain blockage causing your "1Edge" diffraction. This makes your signals fairly weak (in the "red" zone on your signal list).
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True the chart shows 1Edge diffraction but in my post in a different section, I questioned how accurate this is.
When I click on KNBC on the report I provided above, I get a Transmitter Profile Detail chart showing my home is in a blue area (it's hard to see the detail). It shows the blockage comes from some high terrain about 1/10th of the distance from my house towards the transmitter (I know you say the terrain scale is exaggerated).
To see where this hill or mountain was, I followed the Google maps terrain view along the path towards the transmitters on Mt Wilson. Those transmitters are at close to 6000' in altitude. My house is at 1000' altitude. At 53 miles the effect of the earth's curvature would be about 35 feet. (53mx8"). I found a 1400' hill about 20,000 feet from my house along the path to the transmitters. That hill appears to be just enough to cause the 1edge effect. So it seems the charts are accurate. To get full LOS Id need the antenna to be at 340 feet.