K6ARK EFHW Kit is available here (at the time of recording, sold out) - https://amzn.to/3veA5tA - That is an affiliate link, which means I may make money off the purchase of this item. Listen, I know the audio is cutting out/fading out. This is a noise gate thing. I don't have the time to go back and re record this, unfortunately.
K6ARK EFHW Instructions here -
https://docs.google.com/document/d/1G5euBoeTSbF6Jqc6FvO8YTpzVx5Zk1sMcjSNHi5y2LQ/
Link to a diagram on how I wrapped my 49:1 (Minus the cross over at turn 8, DO NOT DO THAT) https://elginradio.wordpress.com/2017/10/17/end-fed-half-wave-antennas/
Note: I did the 49:1 with no crossover as well as a 56:1 (2 primaries 15 secondaries) as tested by @MM0OPXFieldRadio (check out his channel on youtube where he tests a LARGE variety of antennas)
Original twitter post for the 56:1 - https://twitter.com/MM0OPX/status/1554076131220983808.
Finally, you can always link the EFHW (a linked efhw, imagine that). Before making a 40m EFHW, Choose a band, for example, 17m. 17m/2 = 8.5m (27.89 ft) take 27.89 feet, put it on the Antenna out, cut until it is resonate on 17m (you may find it resonate else where, happy coincidence.
After you have 17m cut (again for example), install a banana connector on that and use some sort of strain relief. Then cut 37.71 ft of wire for a 40M EFHW. connect the 17m link and the freshly cut 40m link then check the SWR, it will probably be high at 40 20 15 and 10. Cut the END of the 40m link until 40, 20 15, 10 are good for you. then any time in the future you wished to use 17m, just disconnect the banana connector, while keeping both wires within the strain relief.
This allows for a rapid band change without having to reconfigure the antenna. Will it work on 6m? Probably not.
However, you can continue this process throughout the band. so for example: 12m, 17m, 30m then of course your 40m length which gives you 40, 20, 15, and 10.
All my testing and was tested in the sloper configuration from 25 feet, sloping down to about 3-4 feet.
BNTECHGO Silicone wire - https://amzn.to/3hM3poh (Again, this is an affiliate link)
Good luck with the build, you got this.
Videos to help you:
https://youtube.com/playlist?list=PLQQNWPUnngvfQ6F77ei8wceJcvV3MIdpi