Cushcraft R7000 Vertical Antenna ОБЗОР И ДОРАБОТКИ

Cushcraft R7000 Vertical Antenna ОБЗОР И ДОРАБОТКИ The Cushcraft R7000 is a multiband vertical antenna rated at 1500 watts peak power, 1000 watts continuous, on the 7 through 28 MHz amateur radio bands. Interestingly it also exhibits low VSWR on 6 meters. KP4MD performed analysis on the previous Cushcraft multiband antenna, the R7, which inspired me to update his analysis to the R7000. Modeling was done with the 4NEC modeling program. Many refer to this antenna as a half wavelength endfed antenna even though it s physically less than a half wavelength on most of the bands it covers. In fact it is more like a 3, 8 vertical with the normal 200 ohms +Jsomething (inductive impedance). Electrical length on each band is determined by the traps which also act as loading coils on some bands. The matching network has a 4:1 Balun and RF choke. For matching network details see EI7BA s page on the R7. The capacitance to counteract the +Jxx inductance is achieved through the 49 inch radials which are not radials at al