Chuck wrote in news:1188570780_12655
@sp12lax.superfeed.net:

Under really weak propagation
conditions, that 4dB comes in handy.


Under really weak propagation conditions, that 10db comes in handy....(c;
http://www.alpharadioproducts.com/9500.asp

POWER is our friend!

More seriously, many of you marine hams could sound a LOT better on the
Maritime Mobile Service Net (14.300) by using a TUNED antenna, instead of
the untuned flagpole and awfully-inefficient tuners which suck up lots of
your power and radiate poorly. A 1/4 wavelength "whip" on 14.3 Mhz is
only 16' 4" long and only requires a ground a tiny bit longer to radiate
like mad. I've been using a 1/4 wave vertical made from 1/2" copper pipe
soldered together for decades on 20M digital modes. Its ground plane is
the metal skin of my mobile home roof, but you could simply use a metal
handrail or radar arch like Skip has on the Pig. The bottom of the pipe
needs to be insulated from its mount and the center wire of the coax
cable is simply soldered to it where it comes out of its mount. The
feedpoint impedance is very low so there is little voltage but peak
current at the bottom feedpoint of any resonant 1/4 wave vertical.
Transistor power amps love that.

Once you are off the marine bands onto ham radio, your power limit is
1,500 watts. This also helps people to hear you, of course, the same as
it does Voice of America and the BBC. This webpage shows you some of the
amps available to boost your 100W rig to 500W:
http://www.k0bg.com/amplifiers.html
I've owned the Tentec Hercules II since it was new. His comments about
the crappy power connector doesn't go far enough. All the internal push-
on connectors with high current should be replaced with heavier wire and
hard soldered to the 4 amplifier boards and 1 control board. I'm using #
2 car stereo power cables to connect it to a big deep cycle 12V battery.
Instead of 80A and 400-500W, I can now draw 120A and get 650-700 watts
output to my beautifully-arcing 15' homebrew texas bugcatcher with huge
coils and 36" capacitor hat at 12' off the car's trailer hitch. People
will shout out their car windows at me, "Hey Mister! Your ANTENNA IS ON
FIRE!" The intense RF field it creates will stall most GM computer cars
and trucks who venture near it....(c;

A great 20M HF antenna with no tuner or power limit is simply a 16' 4"
length of #12-16 wire soldered to the center conductor of a piece of coax
to the transmitter. Put a big battery alligator clip on the shield of
the coax, as short as practical. Clamp the alligator to the middle of
the metal handrail or lifeline cable WITH ELECTRICAL CONTACT as far away
from metal rigging as you can get it. Haul the open end of the wire up a
halyard as far out on the yardarm as possible, as far away from the
rigging, again, as possible. Voila! 20 meters comes in like gangbusters
if the band is open and your signal goes up 10 db from the crappy
backstay/tuner arrangement. To operate 40 meters, double its wire length
to 32' 8" 80 meters is around 66' long so isn't practical on most
sailboats. It needs a center loading coil you can make from white PVC
drain pipe with end caps. Put the coil in between the top of the 20M
section and 40M add-on top section...in the center of the 40 length.
Experiment with an open coil to see how many turns of wire you need,
trimming as necessary, then seal the coil up by putting that pipe wrapped
with wire inside another larger pipe with end caps only penetrated by eye
bolts to make contact with the ends of the coil inside. That'll make it
last for years at sea. Tuned antenna simply work better and are worth
the effort.

Larry
--