Since
I was young I have ever dreamed on the day that I could
talk to distance places with a tiny radio and antenna
on my hand.
On
October 29, 2004 when I was complaining 54 I could realize
my dream.
The
radio is a nine AA battery operated 10/11 meters AM/FM/SSB
handy talkie coupled to the base of a small magnetic loop
by the belt clip.
This
type of 10/11 meters AM/FM/SSB radios was sold in great
quantities with brand names like Cherokee AH 100, Titan
RPSY 1020, Magnum 1010, Dragon, etc.
..
I
have two versions of these magnetic loops that can be
attached to the belt clip of the radio.
The
smaller is my very first one made with coaxial cable and
a 3 / 30 PF capacitor covering between 24MHz to 60 MHz.
The tuning on 10 meters and 12 meters is a little tight.
The
second one is made with soft cooper 6 MMS tube.
On
this loop I decide to use a low capacitance split capacitor
and a small piece of coaxial cable to be paralleled to
the variable capacitor acting as a parasitic capacitor.
This solution allows the frequency to be adjusted between
25 MHz with the capacitor closed to 30 MHz when the capacitor
is completely open resulting on a smooth frequency adjustment.
Another
problems is the absent of a SWR meter, that I compensate
making a miniature pick up coil connected to a germanium
diode, a tape recorder VU meter and a 50 K small potentiometer
near the top of the antenna sensing the RF energy on a
AM transmission. In other words a FSM (field strength
meter) is always living on the antenna.
On
the cooper tube antenna, I have I adapted a plastic cylinder
inserted on the antenna wood boom to adjust the view angle
of the FSM with the radio on the upright position.
My
first DX was to the North Brazil region, after that I
have made contacts to Slovenia, Argentina, Russia from
shopping centers parking, on walks and on my condo balcony
surrounded by buildings.
..
