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:
SPECIAL ORDER SABRE 2:1 CUBE Balun™ – (1.8-30 MHz)
(Original product part # was 770013S - circa 1999)
Model SABRE-2-2000 is a 2:1 (100:50) quad core balun used to translate a 50 ohm input to 100 ohms at RF power levels up to 2000 watts PEP when used with a matched load. This assembled balun features a quad core configuration for increased power handling and flatter frequency response to 31 MHz. With a matched 100 ohm load the SWR over the frequency range 1.8 to 30 MHz is shown in the following table measured with an AIM 4170 network analyzer. Notice that the conversion from 100 to 50 ohms is very consistent from 1.8-31 Mhz and SWR is less than 1.5:1 over the range allowing easy tuning by most radio internal antenna tuners or an external tuner. Graph is for a 2:1 balun often used with delta loop, log periodic, horizontal loop antennas and HF Radar.
Input connector is 50 ohm type N (SO-239 also available - inquire).SABRE-2-2000 is in a NEMA 4x4x2 weatherproof box with mounting flanges at bottom to attach to fixed location (mast, wall, beam antenna, etc.).
Eye bolts and studs are all stainless steel for long life.
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