Hi, following on from the disastrous experience of using 2.4GHz for local purposes, where the signal was crap and the microwave knocked out the system, I finally found the time to improve the system. What I did was to take the design for a Quad antenna from
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guessing that the existing "Rubber Duck" antenna was a centre fed
1/2 wave dipole, to construct two 1/4wave long cylinders (from brass shim) which were adjusted to be a good fit over the existing receiver dipole ( one 8.5mm id the other 9.5mm id) and to solder each centre point of the quad, which in the original are connected to an N type RF connector, to one end of each 1/4 wave tube. The assembly is planar, not orthogonal. The gap between the two tubes is about 2.5mm. The resulting assembly slips over the existing receiving aerial with an easy fit. The results were surprising. I guess the received signal is improved by up to 10db!! and is of course directional. The microwave no longer knocks out the signal. I built a few of these assemblies using 2.5mm solid wire and 1.5mm solid wire(2.5mm t & E!) and could not tell the difference. I also found that adding one of these assemblies to a window in the transmission path also improved the received signal level. I'd be interested to hear if anyone else has tried this approach.
Regards Capitol