40m stack completed

Since the weather prediction was so good this weekend, except Sunday I decided to stay extra long at the QTH. Me and SM2LIY made the 40m beam ready to be lifted and we tuned it on Sunday, during quite windy weather but still not too windy to just lift the antenna for tuning. We hoisted it to about 20m above the ground during our measurements and after three attempts we had the beam VSWR dip where we wanted it. After that we attached mast to boom plates and made it all ready to be lifted.

SM3JLA showed up just over the day on Monday to help us. Also SM2XJP showed up as usual and helped us up with the beam. It all went very smoothly except I had to wrestle the beam in the tower since I remembered the width between the tower legs of being 400mm and not 450mm. This meant I had to move the driven element about 3cm so fit the boom/mast brackets and slide the boom inside the mast/boom plates since I had already attached one to the tower. But after 2.5h I was able to climb down again.

Next weekend if the weather allows, we will try to get the phase box up there to connect the stack so we can try it out. The phase box handles BIP/BOP and has an L-match matching the two 50 ohm antennas to 50 ohms. I have been thinking about making a new box in the future, which enables us to be able to just use UPPER/LOWER or BOTH, mainly just because I would like to be able to see the difference, not that I think it will be very useful.

However, according to HFTA and thanks to the statistic files N6BV sent me of SJ2W, the stack looks like it will be a real performer! Just check the HFTA plots of the 40m stack below and tell yourself. I have plotted the single beam at 60m, the stack and the stack out of phase.

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