Morning all, have been testing a homebuilt all copper curlywhirly lookalike. 16SWG enamelled wire, modified magnetic base with direct soldered screen plus a times 2 size groundplane. The antenna is at 27 feet (152 feet ASL). Have tested several double screened best quality (!) 75 Ohm satellite receiver coax and the present, regretably unmarked, appears to be the best. (A friend in the trade donates what`s left on cable drums that appear to be of good screen quality). The feeder to antenna is 31 feet and the attached polar is seven days worth of intercept. Using a 3.4 Gig machine with 3 Gigs of ram. As for using copper, it should be noted that, as it comparitively soft material, there is a risk of if being `bent` by strong winds. It is also advisable to have on hand a wet sponge to immediately cool the solder if applied to a magnet - it`ll loose its strength if heat is applied too long. Another thought is that a little rigidity to the antenna can be achieved by spraying it with `Dampstart`, a propriety plastic spray for stopping flashover on car HT leads. Three all copper antennas have been built with the enevitable variations in size - perhaps plus or minus 1/32" max - and i cannot see any difference in performance. I have a clear line of sight to the NE to SE only - occluded to the west by the Pennines.
Enough wittering, hope this has been of some interest, Regards to all, Roger
