Reflections about a remote mediumwave listeners station

After a long preparation time, a lot of gardening work and a failed attempt to set up the 8 m mast, the double delta antenna is ready and waiting for the connection of the balun / resistance box and the coax cable. As soon as the weather permits, initial tests can be carried out.

The DDA is suspended from 2 guy points at a height of approx. 6 m. A compromise already resulted in the suspension. Anchoring points 8 m high were not possible because a mast bar could not be set up in this length. The horizontal wires run 1 m high. It is fitted with a 16: 1 balun. A terminating resistor has 1 kOhm. The resistor sits in a fuse holder and can be easily replaced with another if necessary. The total scope of the DDA is approx. 90 m. The targeted receiving direction at approx. 320 °. By using quick-change termination boxes, the DDA can also be quickly changed to approx. 150 °.



Pictures (from left to right)
1 Connected balunbox
2 Connected resistorbox
3 The 6m mast with guy lines
4 An aluminum pole in the ash bears the second anchor point
5 + 6 balun box with 16: 1 balun
7 + 8 box with 1kOhm resistor in the fuse holder

Left: In the HT box at 4 m height is a Beverage Antenna matching set. The HT box was overhauled and re-waterproofed.

Middle: the CMCC was connected to the HT box with a 75 ohm coax cable at a distance of 5 meters. The ground rod is a discarded water pipe.

Right: a poplar serves as a holder for 3 long wire antennas, each 50 m in length. Not shown: a 2nd CMCC 5 m away from the receiver.

How are the CMCCs? First tests brought a significantly reduced QRN under thunderstorm disturbances.

Antenna building material for a 350 m BOG. The line should run in NE / N direction, be largely invisible, and waterproof. Most of the material comes from a pasture fence shop, secret slogan: "Your partner for good MW-DX". The antenna is placed as soon as conditions permit on the neighboring meadow.

For construction: The Beverage boxes are installed in watertight HT tubes, the cables are routed through watertight cable feedthroughs. The ground wires at both ends are bolted to the ground rods. An approximately 60 m long coaxial cable is laid underground to the shack. If necessary, the ring insulators are placed in the ground at long intervals, bolted to wooden bars to keep the BOG flat and tight.

The BOG is connected to an RPA-2 Modular Receive Preamplifier by DX-Engineering.