Not content with a small 9:1 unun and trying different bands plus a bit of FT8, I decided to beef up my random length antenna.
I bought two FT240-43 toroids (already conplemplating replacing them with 52’s), a reel of enamelled 16AWG wire and some other bits and bobs, and set to work.
I stacked the two toroids, and wrapped 9 turns of wire in a trifilar fashion. I put this into an IP65 enclosure, and another one beneath it for a choke.
I bought a reel of kevlar full-braid wire for the antenna, cut to 25.6m. I used the “old” dipoflex as radials. Being constrained by space and area, I ran two radials rearwards, one 10m and one 20m, and two forwards, one 5m and one ~7.5m.
Once I had the antenna mounted, I connected up my NanoVNA and was pleasantly surprised at the results. There were dips around the bands, and all in all low readings.
The results while connected live to the ATU are generally good, mostly around the 1.1 – 1.3 SWR mark, occasionally creeping up a little towards the 1.6, which is why I am considering using 52’s.
Most importantly I’m enjoying expanding my knowledge and understanding, and seeing how small changes make a big difference. Below is the construction taking shape. I 3D-printed a holder for the toroids.
