The Equipments
One of the biggest problems in
ham traveling is the equipment. I had prioring experience during
my Contest activity from Lampedusa is. into WWDX 95 / 96, as
IG9R , to move my equipment's and
building up very efficient antennas system to be competitive, but
now my need were a low weight and good performance setup. The
radio was just ready, the wonderful ICOM 706, and the antenna,
the Cushcraft
vertical R7, was just assembled and
packed. I am working in the computer business , so a laptop was
very easy to found in my store, and old Compaq Aero 486 with 8
Megs of RAM and color display was the good choice, no more that
2.1 Kg and a comfortable keyboard. I needed to found a low weight
amplifier and power supply. In the last couple of year I dreaming
a very compact and portable 400/500W mobile station to use in
some contesting or IOTA activity, the 5H1FS opportunity open me
the way to complete my setup. The Amplifier could have some basic
characteristic, Low Weight, High Density, Solid State, 13.8V
Supply from a battery system ( You can found a 12V Battery in any
part of the World) , full protected , automatic band switch,
heavy-duty factor and obviously cheap.. After a couple of month
my search ended with the decision to buy an SGC SG-500
SmartPowerCube 13.8 V amplifier. It is
not the cheapest solid state amplifier, but it's offer a very
unique features, as automatic band switch, auto PTT, and a very
effective full protection, SWR, Power Input and Current
limitation. It is not the lighted, but has a very solid aluminum
case for full power heavy-duty dissipation. The last problem was
the power supply. Due space constriction I will want to use a
single power supply for the amplifier, the radio and the
computer. I needed power supply with a 110 A current handling,
and automatic input range 85 / 230 V AC and no more that 6 Kg
weight. These features could
allow me to traveling around the world without power
supply compromise. The only one solution were a switching power
supply that allow in a very compact case size and light weight an
high current and good power factor. After some search over the
world ( over the NET ), I realize that this kind of power supply
is mainly available in the professional market, for military ad
heavy-duty application, in another word, no cheap !! After some
test with homemade power supply, I decide to buy one of these
professional power supplies, they can give me the realibilty and
guarantee to have a very high effective power system. The Power
Supply was manufactured from the Japanese ETA POWER, they are two 12 V 53A paralleled, all in 5.9 Kg and
very small case size. All was ready to start the adventure. Some
details were still in progress, selecting microphone , headphone,
preparing short RG58 cables, building a little interface between
Radio and Amplifier, building a remote band switch for the
Amplifier, installing the appropriate software a checking all
before the departure.The final idea was to use the footswitch and
a Heil BoomSet headset, so I build a simple box that include the
PTT interface and the remote band switch all together. The
interface is not a real amplifier control with the radio PTT, but
a simple way to insure that the Amplifier is on air before airing
the radio. Two simple two way relay connected in series , the
first one, driven from the footswitch, engage the second one AND
the Amplifier PTT line and the second one ground the radio PTT
line. The Remote band switch was necessary with the SG-500 due
the fact that the automatic autosense band switch introduce a
delay, around the 250ms, any time you transmit, this delay is
unacceptable in a very high rate QSO as I was expected. Well a 7
position rotating wafer switch with 6 led and 2 m of shielded
cable, allowed me to switch the band in remote placing amplifier
and the power supply out of the view, under the operating table.
The software was not so difficult to select, I had two choice
from CT 9.27 or a TOPLOG a Log Program written some years ago
from myself. CT was quit little bit easy to use in a huge
pile-up, as a mainly contest program, so decided for CT,
installed on the laptop, updated the master.dta file, taked with
me some disk for backup propose and the computer were ready , the
most easy thing to prepare.
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