Topband: New 160m array going up at KC1XX

[Tom Cathey]

Hi John,

You guys always come through!  Nice shots and interesting configuration with
the raised radials, ground screen combo and parasitic config for endfire.

Since you'll  be tuning that puppy soon and laying down radials in the bush,
here's some ideas I've found that worked for my  3 el parasitic array that
you may consider:

1) For MAX f-b, the tuning of the parasitic elements has a  very narrow
bandwidth and is critical at the  maximum
f-b point. The null is very sharp and fine tuned.  No different than tuning
a Yagi.

I used a ground mounted tiny FET beacon with an 1/8 wave wire vertical
behind and in front of the array about  600' away and hooked up a receiver
with a sensitive S meter to the array.  I found I could about completely
null out the beacon off the back by carefully adjusting the director and
reflector lengths at their bases. (Maybe 50-60db down)  However, this is
using a "false"  zero degree angle beacon signal and in the real world
higher angle signals were down about 25-30 db off the back.

The f-b bandwidth was only about +_15kc for the intense null on the beacon.
No problem considering the narrow window we use on 160 DX CW/phone.  Broader
coverage would be easy too, just like tuning a Yagi broader as a compromise.

2) For putting down radials in thick bush, I came up with a simple system.
Mount the wire spool at the tower so that it will flow freely in the
direction of the proposed radial. Then tie the wire to a tiny hole on the
end of a  ~10' aluminum pole (1 1/2" dia), lay it on the ground  and push it
thru the thickets with your foot.  This will go thru any bush and especially
good for going under leaves and sticks/logs in the woods.

Keep us informed as to the tuning and any other observations you make. I'll
look forward to hearing that system working this Fall, OM!

Tom, K1JJ
CT