Autumn Antenna Plans

Autumn on Guam brings a continuation of the rainy season, but the temperature maintains the constant year-around tropical heat. Shorter days in the northern hemisphere bring better conditions, and the start of the contest season.

There are a number of projects I would like to tackle over the next month to prepare for the Oceania DX contest, CQWW DX, and other fall/winter contests:

(1) I need to renew my African Beverage wire. I made the mistake of stringing the receive antenna with white insulated, stranded #16 wire. The stranded wire caused it to stretch and sag, and the wild pigs chewed the antenna to pieces, thinking the white insulated wire were grubs or worms (food). I ordered 700ft of #18 copper clad steel wire, the same material I use for my other three Beverages which have been reliable for the last year since they were installed.

(2) Relocate my 40/30m dipole. Right now, my 40/30m dipole is located on an extension above my Spiderbeam, placing the feed point at 50ft. Relocating the antenna to a nearby coconut tree will lower the center by a few feet, but reduce the stress on the rotator. I’m worried it may fail in wind due to the lever action of having 15ft of mast sticking out the top. Also, I am worried about interaction between the 40m dipole and nearby vertical, as well as interaction with the Spiderbeam on 15m.

(3) Raise the Spiderbeam a few feet, from 35 to 40 or 42 feet. Once the 40m dipole is moved, I feel I can get the beam up a few feet higher by telescoping one more piece of pipe at the base (2.5″ at the bottom instead of 2″ that I have now). I’ll need my son to help raise it into place, but that 5-7 feet should be beneficial on 20m, even if only to satisfy my mental thoughts of being louder.

(4) Install phased verticals for 40m. I have room to install a 2nd 40m vertical and phase them toward EU, 90 degree spacing 90 or 135 degrees out of phase (I’ll probably use the Christman method of feeding with 90 degree phasing). The house will effectively block the takeoff toward NA and SA, so I will need to keep the dipole for those directions, but phased verticals should give me some additional gain to try to break through the EU “wall” on 40. Relocating the 40m dipole will help minimize interaction which would make the array ineffective if left in its current location (according to EZNEC).

(5) Renew my 80/160m support mast. The mast is a bit floppy at the far end, and it got tweaked during the recent nearby formation of Tropical Storm Talas which brought higher than normal winds to Guam. I don’t think I can extend the mast any longer, but I need to make it more rigid.

(6) Better SO2R isolation. I need to better configure my shack for SO2R, with the addition of W3NQN type bandpass filters and a new 2nd radio antenna. This 2nd radio antenna (for 40-10m as I can use 80/160 already with the 2nd radio) will probably only be a dipole or other simple temporary antenna, but greater separation by placing it behind one of the vacant next door houses should keep me from blowing up any more front ends.

These projects should keep me busy during the month of September!

My current 40/30m vertical which will make up one of my phased 40m vertical array. The 80/160m TEE is in the background.
Current configuration showing my Spiderbeam and 40/30m dipole that will be relocated to prevent interaction and overloading of the rotator