Water
Tuned Sliding Capacitor Loop
..
On
this loop I decide to associate some successful techniques:
1)The
printed circuit sliding capacitor
2)The water remote tuning system
3)The alligator clip ad on capacitor
The loop is made on 2.50 CMS coaxial cable and it can
cover from 14 to 30 MHz
There
are two ceramic capacitors on the back of the sliding
capacitor calculated to cover 40 and 80 meters.
..
One
of each capacitor legs is soldered on one extreme of the
loop and the other capacitor leg to a short piece of coaxial
braid and then to an alligator clip.
To
calculate the capacitor value I went to REG Edwards’s
formulas page that can be find on the “Magnetic
Loop Links”.
It
is possible to calculate other capacitors to cover 30
Meters and 60 Meters.
The
hand adjusting injection serynger have a calibrated scale
that informs the operating band helping fast frequency
visual information.
This
antenna is very light and the weight is about 800 grams
and it is easy to carry and adjust on a walk and talk
pedestrian QRP operation.
This
antenna was designed for low power use due the low proximity
between the capacitor plates
..
The
coaxial cable and the plastic tube are carefully glued
with Super Bond.
On
the upper left photo shows the coaxial cable and connector
reinforced by thermal shrinking spaghetti, a technique
that must be used on all RF cable and connector joints
that will give additional protection on the pedestrian
operation cable stress.
PY1
AHD ALEX (Alexandre Grimberg).
