[Boatanchors] Maybe off topic: Question about Cushcraft R-7000 Vertical Antenna
D C _Mac_ Macdonald
k2gkk at hotmail.com
Thu Jul 25 21:43:46 EDT 2019
Does anybody actually know the theory behind this antenna?
The length of the bottom section (below the 10 m/12m trap) is definitely more than a quarter wavelength. There is a seven rod (~ 48") radial array at the feedpoint and a small four rod top hat just below the 10m/12m trap. There is some sort of matching coil between the coax feed and the feedpoint. I can't get a reasonable VSWR on 10m so am not surprised that the lower frequency bands also have high VSWR.
This antenna belonged to an SK ham and was damaged when I got it. That previous owner failed to guy the vertical and it folded over at the top of the 10/12 meter trap. I attempted to repair that trap, but apparently failed.
Barring anything else, does anyone have a defunct R-7000 with a good 10/12 meter trap they would sell?
73 de Mac, K2GKK/5
Since 30 Nov 1953
Oklahoma City, OK
USAF, Retired ('61-'81)
FAA, Retired ('94-'10)
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