The ZS6BKW antenna is a better match for our bands than the G5RV. The method of construction and tuning is essentially the same for both antennas but the dimensions are different.
Here is the ZS6BKW antenna installed at AK6R fine tuned for the CW/FT8 frequencies on 40-20-17-12-10 meters. An excellent antenna when installed at 30 feet or higher and no tuner required avoiding the tuner losses and constant retuning. If you want to work all bands from 80-10 install an antenna tuner between the 1:1 balun and the amplifier and ignore the 39/40 switch.
Is this the best FT8 antenna? – I think so as I has made over 70,000 contacts and it still is a proven winner -Good world wide DX, easy to install, no tuner and takes full legal limit.
Here are several different 1:1 baluns you can use depending on power requirements:
Broadband, Non-Inductive Termination Resistor load used on many terminated antenna types such as Terminated Vee (see picture), T2FD, Broadband Terminated Dipole (BBTD), Rhombics, V-Beams and others
Resistive Value: 400 ohms (+/- 10%)
SSB (25% duty cycle) rating in Watts: 600
CW/FT8 (50% duty cycle) in watts: 300
Length (tip to tip) Inches: 11 1/4"
Width inches: 2 1/4"
Inductance < 20 nH (1-61 MHz)Internal Resistance Wattage: 150 watts
Antenna Note: For terminated V antenna shown, use a 16:1 + 1:1 hybrid transformer to match the 50 ohms to 800 (400 + 400) in the antenna "legs"
Here is the Coax Noise Filter used to suppress coax common mode currents (works for all type of antennas)
PDF of ZS6BKW at AK6R Construction Article HERE: My ZS6BKW Antenna