it does not require any radials. this is good for limited space
it does Many Frequency with the ATU , that is build in the Transceiver. it Does Max 250 Watt
Specification : Antenna type HF Broadband Vertical Frequency range 3.5 - 57 MHz > 11 mhz Put extra wire support for lower Frequency Impedance 50 Ohms Connectors SO-239 . PL Type Power rating 250watt VSWR < 1.2:1 with Most ATU Materials (external) Thick Alumunium Mounting from 1-1.5" Lenght +- 7 Metres
This Antenna Has build in Antenna Matcher and Balance Load to elliminate any Reflect due to the Unmatch SWR.
The SWR is Low accross the Band as you can see that we test the unit with Kenwood TS-2000, The Antenna with 7-8m Height,
Effeciency may increase on lower band such as 80 and 40Mhz, when the Element modified to be longer , you could add longer wire on the Base Top section.