Originally Posted by Calaveras
You've just latched on to a theory and come to believe it with no supporting data.
You have failed to answer or even give a plausible answer to any of my questions given in my last post. You keep saying multipath is the explanation.
I have no access to the manufacturer's specific antenna test data. Panel antennas require complex mathematical analysis to design them, and test results are the only way to verify the analysis is correct. A high-gain wide-band panel antenna requires numerous panel modules stacked vertically and radially. All these modules are each separated by a large variety of distances from each other, each sending out separate signals. The signals from each module have phase differences with respect to the signals from every other module. The antenna designer must consider all these phase differences to form the desired beam. This is a wide-band antenna and covers a wide range of frequencies. Each frequency has a different degree of phase shift, and so each frequency will have a different signal strength at ALL azimuth AND elevation angles. Every frequency has a different degree of phase shift and signal strength compared to every other frequency. The manufacturer makes the best compromise in design over the entire range of frequencies.
KMAX and now
, with a frequency change, KQCA have been viewable on this antenna. KQCA, in fact, now has a very strong signal. KCRA, always fixed at channel 35, has always been unviewable from this antenna. In past years, KCRA has been at least somewhat viewable from their backup antenna at reduced power. Their backup antenna was used frequently during the first years of DTV. I haven't been tuned to KCRA in recent years to experience their backup antenna of late. ALL OTHER WALNUT GROVE STATIONS DO NOT HAVE THE PROBLEM KCRA HAS. Why would multipath be a UNIQUE problem ONLY for KCRA? Multipath situations would change with varying weather conditions as well as with vegetation. There is no change in KCRA's reception other than during temperature inversions affecting ALL other channels. Further, my 91XG receiving antenna is pointed towards the sky, above tree height and above surrounding hillsides where there IS NO multipath. By simple logic and deduction, the characteristics of the high-gain wide-band panel antenna, affected by distance, azimuth and elevation angle is the most likely and logical reason that KCRA is unviewable at my location from this panel antenna.
If someone would post when KCRA is on their backup antenna, then I could verify their main antenna is at fault. I've looked for info on the KCRA auxiliary (backup) antenna. This is all I could find:
Antenna Type: Non-Directional
Beam Tilt: 0.7 Degrees Electrical
Description: DIE, TFU-24GTH/VP-R 06
Height of radiation center above ground: 463 Meters
This is the ideal type of slot antenna I wish KCRA was using as their main antenna! It is not clear what ERP is being used for backup transmitting power. The document just says maximum ERP is 1000kW. I would love to see how KCRA behaves on backup today!