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:
20-6 Meter Loop antenna (72' wire) + 500/1500/5000 Watt PEP rated 4:1 Current Balun + internal 1:1 Current Balun in one enclosure + 4 insulators for support
* Complete package - just add coax
* works multiple bands with ease
* can be configured as delta, square, rectangle or multi-sided horizontal loop (4 insulators included)
* Choice of 500, 1.5KW or 5KW PEP rated HYBRID baluns to suit power needs
* No need for extra feed line choke as it is built into the 4:1 balun enclosure
After many requests we have created a compact, special balun for OCF and loop (Skyloop or Delta loop) antennas. The CB-4-1-1500/5000 is a CUBE enclosure containing a multi-core, broadband 4:1 impedance transformer in series with a 1:1 current balun for extra common mode current choking to keep RF current off the outside of the coax braid and on the antenna where it belongs. The extra choking action also means that the coax feed line will not act as a radiator causing unnecessary RF interference (RFI).
1.5KW Rated for full 1500 watts PEP and 1000 watts CW/FT8 (ICAS). 1.8Mhz – 61 MHz.
5KW Rated for full 5000 watts PEP and 1500 watts CW/FT8 (ICAS). 1.8Mhz – 61 MHz.
500 watt version is in "BULLET" format, 1.5KW is a 4 x 4 x 2 cube and 5KW is in 4" x 4" x 4" enclosure.
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