Description of station


The TS940 came in the middle of the eighties as a successor of the TS930 on the market.

The receiver has a frequency range from 0,1 to 30 MHz. For all modes of operation (single-sideband modulation LSB, USB - telegrafie CW - amplitude modulation AM - frequency modulation FM - digital modes of operation the FSK) the TS940 effective filters those could have as required been adjusted. There is two VFO's, 40 storage locations, a clock as well as SSB Slope Tune and CW VBT (super).

The transmitter has a transistor output stage with adjustable power output to 100Watt and a self seeking tuner. In the construction as High ending equipment is this Transceiver today still likes and, depending upon equipment (filter assembly, Antennentuner, condition), used around 800 euro is acted.

Used accessories:

Keys - ETM (Squeez elBug), Junker; Microphone - Kenwood MC80, Loudspeaker - Kenwood SP950; Headphone - Koss Porta pro

Berlin repair service: 

www.funktechnik seipelt.de


The transmission amplifier FL-2277 von Yaesu is a tube amplifier with two tubes of the type 572B, and the direct forerunner of the well-known FL-2100 output stage. They are identically constructed in many ranges. The 2277 1973 of Sommerkamp came on the market.

Volumes - 10m - 15m - 20m - 40m - 80m.

Treasury rate - 70 Watts of max.

Transmitting power - 600 Watts of max. with 2400 V anode voltage. Lately Chinese tubes are 572B on the market... Caution! These are examined by the manufacturer only with 1000Volt.

The amplifier can be operated over foot switches with something absorption in the RX (to hear by the tubes) or by means of control line by the Transceiver (to have faster relays to be then inserted) also fully QSK.



The FC-902 came 1981, suitably the FT-902, on the market.

He can adapt symmetrical and asymmetrical antennas on all HF bands. It has an inserted SWR meter, power indication to 500 Watts and an inserted quadruple antenna changeover switch.

With the selection of the antenna first the location is the center of attention. How do I have much place available? How is the land development in the direct near field? Next the question of cost places itself. A commercially manufactured antenna does not have to be more expensive always than the self's building. The self's building offers itself with the building of wire antennas. One does not have to again invent the wheel here, it gives a multiplicity of established antennas. Here, in germany, "Rothammels Antennenbuch" is mentioned as standard work. In each case the effectiveness of the antenna system decides on successes in the short wave radio.

If one would like to cover the entire high-frequency in the outdoor enterprise with an antenna, one should use the Doppelzepp or the current sum antenna. These horizontal dipole antennas become with a symmetrical feeder (chicken leaders) and a antenna antennen-Tuner excited. The antenna length amounts to approx. 40m, the feed should with 20m height lie. One does not know the antenna will so highly attach it on the deep frequencies to the steep emitter. For European traffic still another structure height of 10m is sufficient. The antennas can be developed also as Inverded Vee. The dipole thighs should however at least be highly fastened to the ends 2,5m.

Due to my location in Berlin I was to be built forced an antenna under the roof. The assembly has however the advantage of the maintenance-free operation. Old building, timber roof, 5. Floor. The wire antenna system as loop offers here a large advantage compared with a long dipole antenna, the house QRM is less. I think that the closed loop is better against static loadings. On 40 meters and in DX traffic the loop antenna offers better field strengths at the signal-strength meter. However this antenna has also strong lobes on the high frequencies toward Asia and the The West Indies. In order to adjust the losses toward South America and Africa, I built still three mono band antennas. For 15 and 20 meters horizontal dipoles and for 10 meters a vertical dipole. On 80 meters the loop antenna is through by the antiresonant circuit only one makeshift, sufficient for Europe QSO's however. As inlet for the loop I use a doubly led coaxial cable with 93 ohms result in 186 (~200Ohm) with a length of 12.5 meters. All cables can be laid in such a way within the house, which does not go with open chicken leader.

Against "HF in shak" one makes do best with a coat line trap. This is switched directly after the transmitter exit into the antenna inlet. Andreas, DL7AUY attached such a part. Ferrite single-aperture cores, from remainder postpost remainder posts, are pushed on a length of 30 cm onto a piece of RG-58 coaxial cables. Over the ferrites a plastic pipe is fastened. The cable ends are with POLARIZE plugs provided.


Main antenna Loop Skywire 40m, Feeder 2x RG 62A/U, Z=186Ohm, Coaxtrap 3.5 MHz
Mono band antennas Vertically dipole for 28 MHz, dipole for 21 and 14 MHz
Artificial antenna FD3 21m, Feeder Wireman, Z=450 ohm
Accessories Antennentuner Yaesu FC 902, transducer 4:1 Balun

Christian DL7JV, 2004