[Boatanchors] Maybe off topic: Question about Cushcraft R-7000 Vertical Antenna

[hwhall at compuserve.com]

This seems to have useful info & some links for more:
http://kf6hi.net/radio/r7000/KF6HI_R7000.html

Apparently, it is supposed to be ~1/2 wave electrically, so that's why its longer than 1/4 wave physically.  There's supposed to be a matching network box at the feedpoint.
WayneWB4OGM

-----Original Message-----
From: D C _Mac_ Macdonald <k2gkk at hotmail.com>
To: boatanchors at mailman.qth.net <boatanchors at mailman.qth.net>
Sent: Thu, Jul 25, 2019 7:44 pm
Subject: [Boatanchors] Maybe off topic: Question about Cushcraft R-7000 Vertical Antenna

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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