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"Ionic Liquid" Antenna
On 9/8/2010 10:50 PM, Richard Clark wrote:
On Wed, 08 Sep 2010 21:35:19 -0700, Roy wrote: so either my (and Frank's) calculations are grossly incorrect or SPAWAR thinks there's a market for such inefficient antennas. The point I caught, and apparently was not modeled, was the discussion of antenna height for any particular band. Albeit, such mention was fleeting, but it sounded suspiciously like half wave, not quarter wave dimensions. Aside from that speculation, power specs for military usage are appropriate for theater operations, not global communications. When I taught UHF/VHF in the Navy, 10% efficiency was considered perfectly acceptable as point-to-point communications was the only expectation and that was rarely as much as 20 miles at best. Experience teaches that even that only takes 100s of milliwatts. 73's Richard Clark, KB7QHC That's still an order of magnitude better than what this antenna seems able to do at VHF, although the demonstration clearly showed it to be adequate for working a local repeater with an HT. But what about HF, which the video clearly mentions? Is a fraction of a percent efficiency adequate for typical communication needs? I know that some military HF use is NVIS, for which a vertical antenna is poorly suited to begin with, so that probably wouldn't be an application. Are milliwatts of radiated HF used and useful for theater communications? Roy Lewallen, W7EL |
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