[Fwd: LF: IK1ODO Tests]
Sun, 16 Aug 1998 12:08:32 -0400
M. Bruno wrote:
> At 12.21 16/08/98 +0100, Andy Talbot G4JNT wrote:
> >Just about managed to detect a signal from IK1ODO initially around 0400 -
> >0500z, this morning (Sunday) but the signal was so weak that I had to use a
> >bandwidth that smeared the CW characters and so couldn't read the callsign
> >properly. However, the waterfall plot does show some structure that appears
> >to be consistent with 20 second dot length CW so I'm reasonably sure the
> >signal received was genuine (0.21 Hz high)
> I'm very happy! thank you very much for your effort, Andy, Peter and all
> About the comment of Toni on mountain attenuation, in effect the Alps here
> are about 2 Lambda high in northern direction. I suppose this will affect
> the ground signal, and it seems that the sky-wave is not helping.
> Currently I have 2.3 - 2.5 A input on the variometer. The radiation resistance
> should be abt. 16 mOhm (8 m high wire, two top wires parallel spaced 1 m,
> 27 m, ca. 370 pF capacity). The total loss resistance is 40 Ohm. The
> has 50 cm diameter, 2 mm wire. Loss of the variometer is abt. 4 Ohm.
> I measured the signal at 4.5 km distance, measuring the field strenght with a
> calibrated EMC loop antenna. The computed ERP is 50 mW, but the antenna
> was indoor, so I assume some attenuation by the building.
> I will conduct another test by next week, using longer dots (60 sec?). Also,
> the TX frequency will be controlled by a Rubidium freq. standard (to be
> absolutely sure, and to use the Rubidium for some fun scope).
> 73 - Marco
> Marco Bruno - IK1ODO
> SPIN Electronics - www.spin-it.com