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:
The “Bullet” End Fed Antenna Counterpoise Kit
Th kit contains 1 pre-assembled counterpoise wire which easily attaches to the counterpoise connector on the BULLET matching unit. Improves performance on 1 or more bands. Black/Gray/Blue wire is standard.
Application Note: This kit is typically used with only with Bullet Antenna systems like the 41 foot, 71 foot, 92 foot, 111 foot or 155 foot when you DO NOT USE the coax braid as the counterpoise (such as when you coax is too short). The counterpoise radiates just like the other half of a dipole so DO NOT GROUND IT! It is used to fine tune particular bands (by varying the length to get the lowest SWR reading on as many bands as possible. Multiple length counterpoises can also be used if needed for a particular band) if your particular antenna geometry doesn't show a low enough SWR on a particular band.
Suggested counterpoise lengths are as follows:
41 foot antenna wire needs a 16 foot length (20 feet of wire supplied so you can adjust as needed by folding back on itself)
71 foot antenna wire needs a 42-50 foot length (50 feet of wire supplied so you can adjust as needed by folding back on itself)
92 foot antenna wire needs a 90 foot length (100 feet of wire supplied so you can adjust as needed by folding back on itself)
111 foot antenna wire needs a 37 foot length (50 feet of wire supplied so you can adjust as needed by folding back on itself)
155 foot antenna wire needs a 95 foot length (100 feet of wire supplied so you can adjust as needed by folding back on itself)
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