Tuning the 80 meter coil of the HF2V messed up my settings on 40 and 30 meters in a way that I ended up with barely acceptable SWR on all 3 bands. I definitely needed a new tuning strategy.
It seemed to me that adjusting the lower bands influenced the higher ones but adjusting the higher bands did not have drastic influence on the lower ones. Thus, the obvious strategy is to do the tuning starting with 80, then 40, and finally 30. For reference, here are the starting parameters:
| Band |
L/S |
fc |
SWR |
Width |
| 80m | 31cm / 0t | 3.88 MHz | 1.40 | – |
| 40m | 26cm / 7.5t | 6.88 MHz | 1.06 | 180 kHz |
| 30m | 26cm / 2.5t | 9.96 MHz | 1.20 | 740 kHz |
I started by squeezing the 80 meter coil to L80=22.5cm. This resulted in a 1.3 SWR at fc=3.58MHz. 40 and 30 got shifted slightly down. In order to fix the 40 meter bands, I changed the shorting from 7.5 to 8 turns. Magically, this fixed both the 40 and the 30 meter bands! Also note that the band width on 40 got almost twice as large. So, here are my final settings:
| Band |
L/S |
fc |
SWR |
Width |
| 80m | 22.5cm / 0t | 3.58 MHz | 1.30 | 75 kHz |
| 40m | 26cm / 8t | 7.009 MHz | 1.10 | 360 kHz |
| 30m | 26cm / 2.5t | 10.06 MHz | 1.23 | much |
I am very pleased with these results. Also on 15, the SWR is 1.2 flat between 20 and 22 MHz. I have decided that these are going to be my final settings for now, and the reference settings for the future.
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