This plot shows my low inv-V (30m apex is only 0.19 wavelengths) compared to my 3 element parasitic vertical. Study the relative gain vs TOA plots carefully:
Ooops...bad link. Use this one: http://users.vnet.net/btippett/new_page_10.htm On Mon, Apr 2, 2018 at 7:10 AM, Bill Tippett <[email protected]> wrote: > FYI in response to two recent threads: > > http://lists.contesting.com/archives//html/Topband/2018-03/msg00139.html > http://lists.contesting.com/archives//html/Topband/2018-04/msg00043.html > > This plot shows my low inv-V (30m apex is only 0.19 wavelengths) compared > to my 3 element parasitic vertical. Study the relative gain vs TOA plots > carefully: > > http://lists.contesting.com/archives//html/Topband/2018-03/msg00139.html > > My observations over the past 14 years comparing both: > > 1. The vertical array is best 99% of the time. Usually by ~10 dB to the > NE (e.g. EU/W1 from here). From the plots you can see this equates to TOAs > (<20 degrees). > > 2. The inv-V (wires running NNW/SSE) is occasionally (1%of the time) much > better to EU or other directions at my local sunset or sunrise. This is > striking when it happens and is easy to detect since the inv-V is also > better for RX than either Beverages or an RX4SQ. This is clearly some sort > of high angle mode around SR/SS and it usually lasts for <30 minutes. > > 3. The inv-V BW is much broader than the vertical array which is very > narrow (~30 kHz). > > 4. TX antennas are separated by about 100m on different towers and the > 30m inv-V height is near optimum for maximum radiation straight up > (intentionally). > > 5. The inv-V also works well to the SE (Caribbean/SA) even without SR/SS > enhancement. I have no idea whether how it would behave if rotated 90 > degrees since my site doesn't allow for that. > > Just FYI, > > Bill W4ZV > > > > > _________________ Topband Reflector Archives - http://www.contesting.com/_topband
