Like with any other multi-band vertical the different bands are coupled with each other. This means that modifying the settings on one band will influence the others. This effect is worst on the low bands (40 and below) and less noticeable on the higher bands. If you only have the basic two-band HF2V there are only two bands/parameters to adjust and you can easily get through the alignment by doing a few iterations on each band. However, if you have the 30 or the 160 (or both) extensions mounted, aligning all 3 or 4 bands can become an endless process.
The Solution
As it turns out - at least with my HF2V - adjusting the lower band coil has greater influence on the higher bands than the opposite. Therefore, the only way to achieve proper alignment on all bands was to start with the lowest band, in my case 80. Once it was aligned, I continued with the next band and so on.
I do not know whether it also applies with the 160 meter extension kit, since I have not mounted it yet.
Results
Below you can see a table summarising the parameters and measurements I ended up with. I believe I obtained very good results, considering the difficulties caused by cross-band coupling normally encountered on multi-band verticals.
| Band [m] | Length [cm] | Shorted [turn] | fc [MHz] | SWR | Width [khz] |
| 80 | 22.5 | 0 | 3.580 | 1.30 | 75 |
| 40 | 26 | 8 | 7.009 | 1.10 | 360 |
| 30 | 26 | 2.5 | 10.060 | 1.23 | much |
| 15 | - | - | 21.000 | 1.20 | 2000 |
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