Ham Radio Vertical HF antenna

Excellent explanations about antenna radial systems are provided by some manufacturers, for example by SteppIR and Bencher (english text):

Diamond BB-7V Wideband vertical antenna

QRV on all bands, even with restricted space... the BB-7V antenna is 6.7m long and has a max. power load of 250W PEP. The SWR above 3MHz is, depending on surroundings, at 2:1 or better. On some bands a simple tuner is required, the built-in tuners of many rigs are usually sufficient. The BB-7V is a wideband antenna, so it works also outside the amateur bands. Simple installation, no alignment required. The antenna does not require radials, the radiator is grounded.
Connector PL jack, the small transport length only 1.3m makes this antenna also suitable for camping or other portable uses, weight 3kg.

Technical data
Frequency: 2 to 30MHz
Max. power rating: 250W
Impedance: 50 Ω
VSWR: Less than 2:1
Length: Approx. 6.7m
Weight: 3kg
Connector: PL
Max. Diameter of mast: 60mm
Type: Ground plane

GPM-1500 Wideband vertical HF antenna

Multiband vertical antenna for 1.8 to 30MHz, with reduced efficiency also useable on 50MHz.
Requires a simple coax tuner for operation, the built in tuners usually work well, in some cases a tuner extender (e.g. MFJ-914) is necessary.
The antenna can be installed anywhere, either on the rooftop, on the trailer hook or on a camper car during vacations. Due to the slim body the antenna is very unobtrusive. The antenna is fed with a coax cable of any length, PL connector. The radiator is grounded, thus preventing static discharge. Weight only 4kg, transport length only 1.3m, so it fits even baggage on air transports. The vertical distance between the U-brackets is 26cm.

Technical Data