On Wed, 1 Feb 2006 12:59:11 -0600, "hasan schiers"
wrote:

================================================= ====================
1. Feeding the center conductor of the Inverted L. Coax runs underground 50'
or so, then connects to my radial plate/coax connector. That arrangement
stunk. Band noise S-0, strong signals S-7. Worked about 10 or 15 stations..
Lots of calls unanswered. VERY PREDICTABLE, a poor performer to be sure.

2. Feeding the Inverted L conventionally...same result as 1 above. Perfectly
predictable.

Hi Hasan,

You say the Inverted L works on 80, so we will leave that alone.

END OF Inverted L Experiment.
================================================= ==============
Begin CW-80 Experiment: (OCF Dipole with Line Isolator) up 42'. 85' one
side, 51 feet other side.

CW-80: 50' underground coax, then about 45' of vertical coax to the
feedpoint of the CW-80 (OCF)

1. In other
words, I didn't just plug the CW-80 coax into the tuner and try to tune it
up on 160. I was afraid this might cause the "Line Isolator" to fry (the one
located 22' below the feedpoint of the CW-80)

Aside from the odd tail (the drop to the choke), yes you do stand a
real chance of Common Mode current due to the deliberate imbalance
(the Off Center of the OCF Dipole).

However, when you are driving both sides shorted (or even just one,
singly), the choke is going to be engaged and become a loss (this may
be one reason why it matches well). This is the nature of choking
afterall. If it is built to present enough Z in the 160M band, it
could even disconnect the top hat (but that is not what you are
reporting). Something about the "Line Isolator" seems to lack a
choking action (which further suggests it doesn't choke and it doesn't
isolate).

Anyway, low 160M dipoles nearly always have dismal reports here. On
the other hand, strapping both side of the driveline together and
feeding that, as you say "random wire," often brings good results if
the dipole is high enough. Low/High? and for the same height for the
same band? The kicker is one is horizontal polarization, the other
vertical. That height is too low for horizontal, but suits vertical
polarization better.

3. Shorted the center conductor to the shield and fed that to my tuner
center conductor output as a random wire. (Thus using both the shield and
the center conductor in parallel as a "random wire". This configuration did
not work any better (and perhaps slightly less band noise) than solution 2
above.)

Perhaps because with a hot shield, and ground so close for so great a
distance....

================================================= =================
The full layout of the tower and two wire antennas:

Tower is 48'. At 46' or so, I have a 10' metal horizontal cross boom for
pulleys (see below) At 50' I have a 6 element log periodic for 13-30 mhz. at
60' I have a dual band homebrew J-Pole for 2/70cm. So the total vertical
height is about 65', with whatever loading the LP has. The LP only has a 14'
boom.

Sounds like a perfect platform for a top loaded 160M vertical. Take a
cue from your recent success with that polarization and work with what
nature has given you.

Hopefully, this clears things up.

The only experiment I'm left with is adding a KW-80 80m trap to the 80m
inverted L and then adding sufficient wire to get resonance on 160. I take
from your prior comments that you don't think this arrangement will work any
better than the "dumb luck antenna" I stumbled into. I'm inclined to agree,
as the 42' vertical section of the Inverted L isn't all that great for
160...but one never knows.

It's a 1/16th wave tall (or a quarter of a quarter), but top loading
will boost that to maybe 1/12th wave tall - still no great shakes.
However, experience has shown you were surprised with a "dumb luck
antenna" that has no more advantage in height. Thus it follows that
even as short as that still brings reward.

The long and short of it is that there is probably little to gain (pun
intended) with more work. I would still suggest moving the feed point
away from the back of your tuner, and:
The only improvement I would see is to break the OCF Dipole's coax at
ground level and feed THAT shorted together with the coax coming from
the shack (the newly broken end). Attach the short to the center
conductor, and the shield of the coax from the shack going to the
ground field. When you want to use the OCF Dipole in the conventional
way, open the short, remove the ground and connect in the conventional
way. This could be reduced to a couple of switches at ground level.

The absolute long and short of it is: "don't look a gift horse in the
mouth."

73's
Richard Clark, KB7QHC