Tuning the HF-P1 vertical antenna for 6m and 4m bands

According to the manual sheet you should just push the extender section to the bottom for 6m (50 MHz) but this did not work for me. Using a NanoVNA I could find a workable configuration for both 6m (50 MHz) and 4m (70 MHz) bands.

For both bands I only used only one base pin (instead of two for HF), the coil pushed down to it’s lowest position and the tuning was done using the telescopic top part. The telescopic top part was extended partly:

6m8 sections of the top part extended, top part length 79 cm
4m2.5 sections of the top part extended, top part length 28 cm

If anyone has a better take on tuning on these bands please let me know 🙂 I have just tuned on SWR, no clue what the radiation pattern might be. Also, note that these are measurements that worked for me. Check your SWR.