[ADTech]

An omni antenna can only achieve higher gain by focusing the beamwidth to a narrower set of dimensions. That's moderately easy to do with a vertically polarized omnidirectional element and when dealing with vertically polarized signals such that the main lobe is focused on the horizon to maximize T/R range. However, the default North American polarization is horizontal (some stations do include a vertical component to make a circular or elliptical polarized signal) which makes most of the methods that worked for a vertical element not very useful anymore.

When dealing with ATSC signals, an omni has a distinct disadvantage in that it cannot discriminate between desired signals and undesired multipath signals (which have been found to be the bane of the current ATSC system) nor can they reject undesired noise from off-axis directions. Generally, omnis will be low-gain, usually less than 4-6 dBd. Uni-directional antennas, OTOH, can readily achieve peak gains in the 12-16 dBd range in the UHF band, up to perhaps 10-12 dBd on the high-VHF band (174-216 MHz).

Still, if it works, it works, so the desire for an omni reception pattern is certainly understandable for folks in many areas where broadcast towers are not co-located. San Diego is one such metro area with three main transmission locations (La Jolla - VHF only, Mt San Miguel, and Tijuana) which, depending on the receiving location, can call for very antenna configurations to have the best odds for success.

While the specter of a spectrum auction and re-pack is certainly looming, there is little to no interest in the major broadcast groups relocating to VHF from UHF. If the process goes through, there will be some migration, but it won't likely be very many stations that do move as most will more likely utilize some sort of channel sharing arrangement. Of those that do move, most will be in markets where the spectrum is already full and there are no opportunities for channel sharing or a more desirable broadcast channel. Given that the administration has already twice postponed the auction and that there are continued legal challenges to to, it may turn out to be a long, drawn out process that takes substantial time to get through, if at all. Time and politics will tell.


It would, of course, be interesting to see pertinent details of your antenna such as gain, VSWR, beamwidth, and polar patterns.