NVIS Antenna

I have been testing a design for an NVIS antenna from dxengineering at http://static.dxengineering.com/pdf/WP-NVIS-Rev2.pdf

I liked it because it used many materials I already had and most importantly would fit in my backyard.

I already have 1/2 size G5RV, which seems to work fine on 40M and above, but meant I did not have 80M capability and for ARES, it is recommended to use 40M/80M, 40M during the day and 80M for night time.

I built the "Centre T" out of kitchen cutting board and drilled holes for wires and bolts to go through and also used a second cutting board to make "End Insulators".

It seemed to tune up on 80M but not on 40M, so I borrowed my friends Antenna Analyzer and found that all my frequencies were too low, so I cut and tested, then cut and retested and cut and retested until I got SWR's in suitable ranges for the antenna.

This is the latest graph, showing my G5RV, and then each subsequent cut of the NVIS, showing it getting closer each time to a band.

It seems to be well set for 40M, 15M and 10M and most other bands have low SWR under 2:1.

I do use a tuner, which is capable of bringing in a 10:1 SWR down to 1.5:1, but would prefer the antenna to be tuned properly in the first place.

80M however is still at 3.5:1 and I do not want to cut any more on the 80M side of this NVIS antenna.

My next option is to add lengths to the 80M side to see if I can bring the 80M band in line, by going longer than I originally started out with, though to fit in my backyard I will have to drop the last 10' or so.