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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