DL7JV

OUTDOOR ENTERPRISE

Since in the last years the QRM in the city continued to increase, I arranged 2003 second short waves station for portable enterprise. The following criteria were the basis thereby: - the complete radio station is to fit into a small car. - It should be 24 hours of HF contest, energy-independently in the 100 Watts class possible. No expensive "highend" technology, since nearly everything had again to be purchased.

The choice fell on a ICOM IC-718. That is a pure short waves equipment of the newest generation with 100 Watts of output stage. As extra a high-stable quartz oscillator is inserted, for SSB the DSP- unit and for CW 500 Hz filters. One switched-mode power supply with 13.8 V and 20 ampere of G. Dierking serve as current supply. During the day a small 2-Takt syncron generator with 240 V runs with 750 Watts and 20 Kilos. In the night 2 car batteries with 12 V each of 36 are parallel switched.  The batteries are during the day loaded. The capacity of the batteries is enough, depending upon transmitting power, 6 to 8 hours. A small Antennentuner (Kenwood AT-130), the ETM key and headphones were present. With the laptop for logging DD6KE, Udo helped me. It gave me an old 486ér with LCD announcement.

As horizontal wire antenna I use at present a double dipole, 38 (19/19) meter and 19 (9.5/9.5) meter. This becomes at the easy Spieth mast in approx.. 8 meters height attached. Those altogether 4 dipole thighs are arranged in the 90° angle (plan view is cross-shaped). The thigh ends should be attached 2.5 meters above ground. If a 50 ohm of coaxial cables is used as feeder, the antenna is on 40 and 80 meters in half wave resonance. With a two-wire line one can make all band enterprise.

In comparison to a FD4 or to the Doppelzepp (only 8 meters structure height), is this dipole on 40 and 80 better at European Union QSO's even up to several s-stages. The idea to this antenna came out from the emergency. We were on the island "Ruegen /P" and had only a long 50 ohm cable and some meters of braid H05-VK. We had made by day with tripolleg GP well enterprise . In the evening  we wanted to be QRV on 40 and 80. We built a dipole for 80 with 2 times 21 meters. The SWR to 40 was however bad and had to be adjusted with the tuner. It was still enough braid there, then we cut a dipole for 40 with 2 times 10 meters and closed, like described above, everything together. By a shortening of the wire lengths the SWR without tuner could be adjusted well.

Since with the portable enterprise all one up again and again and one diminishes, transport containers are necessary. Everything is in such a way accommodated that one can use also individual components for other purposes. All feeder lines are prefabricated, putting or screwable. Banana plugs and sockets worked in the best way. Without cable straps, tape, screws and nuts/mothers if possible one does. 12 V of inlets at the laptop and at the battery charger are two-pole wound around staff ferrites against HF disturbances.

EQUIPMENT

Aluminum suit-case

IC-718, switch power pack, ETM-5C, o-Mike, headphone, set of cables

Aluminum suit-case

AT-130, Balun 4:1, antenna changeover switch, general tool, laptop, set of cables, disks, CW PTT Keying

Antenna bag

Aluminum mast and auxiliary mast 9m, herrings, hammer, bag width 1,4m, nylon-hurry, braid 2x19m and 2x9,5m; RG58 12,5m; RG69 12,5m doubles;

Metal box

Battery 12V/36Ah, battery charger

Metal box

Battery 12V/36Ah, 12 v-distributors, set of cables

Generator

Generator, 2x 5 Lieter gasoline, 2-Takt oil, 240V-prise, cable drum 20m triple 240V, engine tent, 2 lamps, engine tool

Camping

Folding table, 2 folding chairs, 2 men steep wall tent, food supply, rain things, luftmatratze

Christian DL7JV, July 2007

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