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:
All coax I/O and control lines and AC/DC power line for SPE-2K-FA amplifier with multiple RF inputs and outputs, control/keying/frequency I/O.
Included are the following chokes and installation guidelines to suppress RFI in and out:
RF Input (3x):Ring Filter (1.4” ID) – 5-9 turns of RG-58/8X size through center
RF Output (6x):Snap On Filter (1” ID) – 3 turns of coax cable through center
Relay Cable/ALC Cable (4x):Snap On Filter (1/2” ID) – multiple turns through center
CAT/USB (5x):Snap On Filter (1/2” ID)- multiple turns through filter for each ACC
AC Power:Snap On Filter (1” ID) – 3 turns of power cord through center
You get 1.4" ID Ring x 3, 1" ID snap on x 7, 1/2" ID snap on x 9 with each kit.
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