Denny Page via time-nuts writes: > No, no ground plane. Don’t really have a lot of room for that in the > window. Out of curiosity, how large of an impact have you found with a > ground plane?
As long as we're talking ceramic patch (puck) antennas, I've seen around 15dB improvement repeatedly (as reported by the receiver statistics) with otherwise non-optimal placement of the antenna (indoors, viewing the sky through a wooden roof covered with rolled roofing). As mentioned elsewhere in the thread, the better antennas come with their own (optimized) ground plane if they need one. Good luck finding data sheets for the puck antennas, but if you do get hold of one, sometimes they do show how the directivity changes with different sized ground planes. If you have a magnetic puck you best use a magnetic steel surface, the cap of a large diameter can works quite well also. Otherwise aluminum foil is just as effective and easily cut or folded away if you want to try to exclude reflections. With multiple active patch antennas going to different receivers, I've found that at least the antennas I have do not like to be placed very close to each other. Spacing them at least half a wavelength from each other seems to take care of that. If the backside shield of the active patch antenna is connected to ground, then the ground plane must be isolated from all (but possibly one) antenna; otherwise the resulting ground loop will degrade reception. Regards, Achim. -- +<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk Blofeld]>+ Samples for the Waldorf Blofeld: http://Synth.Stromeko.net/Downloads.html#BlofeldSamplesExtra _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.