Topband: How much does top loading help?

[Herbert Schoenbohm]

For the past week on 160 meters I have been agonizing over the inability 
to be heard in Europe.  My 500 foot east Beverage has been a thrill to 
listening to but calling RA3DOX for an hour and still no qso has not 
been.  I was able to squeak out a 239 report from G6VZ and got RA6AX to 
call me Bruce and identify me as K1FZ!  Even DF2PY with his booming 599 
plus signal could not hear a peep from me. Wolf has a superb location 
and a very fine setup.

I did manage a 449 report after many call from ZS6UT and a 449 report 
from IV3PRK after calling him for over an hour. So what is the problem. 
 I use in the TX department a 76 foot Rohn 25G (68 feet with a ten foot 
pipe on top.)  20 radials, half of which are #6 bare copper  130 feet 
long and laying on flat soil of fairly good conductivity.  A brackish 
water table is only 10 feet below the surface since I live next to a 
large salt pond lake (Its called Great Salt Pond) The other radials are 
long pieces of insulated #2 wire of various lengths 50 to 60 feet long 
which also lay on the ground. The tower is shunt fed with a #6 copper 
wire separated about 24 inches from the Rohn 25 G and tapped at the 40 
foot point.  An L network with a broadcast TX flat wound coil and a 
500pf 15 KV vac are used to do the match.  I have a 1.5 to 1 SWR over 20 
Khz of the low end near 1.830.

The TX performance has been disappointing, until:

yesterday when I decided to mount the 26 foot boom, just the boom, of an 
uncompleted 204 BA on top of the pipe which extends out of the tower. 
 The low point of VSWR dropped to 1809 Khz indicating I had done 
something to raise the radiation resistance slightly. I know it is not 
very scientific but last night instead of calling eu stations endlessly 
and if worked getting embarrassing reports it went like this:

SM4CAN 599 both ways on the first call.
G3XGC 589 on the first call.
ON7GR 579 on the first call
G4VGO 599 both ways on the  second call in heavy traffic.
ON6AA 599 both ways on the first call.

The problems in getting to excited with this is that there was an 
absence of Eastern European stations and propagation could  have been 
 vastly different.  Still I was very impressed by what a horizontal 26 
foot piece of aluminum tubing appeared to do for me.  I hope this is 
more than just wishful thinking.  I am working today on putting the 
elements together from the remains to three major hurricanes in hopes it 
will help even more.

Please let me know if you have had any similar experiences with some 
simple top loading to a vertical making a huge improvement in radiation 
efficiency and lowering the take off angle.

73

Herb, KV4FZ