On june17th the stations DL2NDO and DJ2LF had a duplex QSO in cw, one way on
8953Hz, the other on 10.368200MHz. Frequency ratio 1:1 158 067.
On 8953Hz DJ2LF transmitted 12W from an AF amplifier with 2 tubes EL12/375 via
loading coil 0.4H and 136KHz antenna. DL2NDO's receiver from 0 to 30MHz was
homemade with a tuned front end for 8953Hz. Antenna 15m wire 10m up.
He transmitted on 10GHz with 0.2W and antenna 50cm diameter. The receiver at
DJ2LF site was an old wide band FM transceiver with gunnplexer and 100MHz IF.
To this IF a 1000Hz
ozillator was connected which always started when a strong carrier was received. So the cw signals were copied clearly despite the gunnplexer. The 8953Hz link worked immediately, but not the 10GHz. The reason was: DL2NDO put the 10GHz equipment behind the closed window. But the the window plane was coated to avoid thermic losses. After opening the window the signal was loud and clear. Distance about 1Km.
73 Walter DJ2LF
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