This antenna is for use with 802.11b wireless computer networks or 2.4GHz video sending equipment.
From experience of useage in a variety of situations and surroundings, I would estimate the gain of this antenna to be around a 3 dB improvement over a Buffalo pcmcia card internal antenna , with a much smoother polar coverage (allowing for the losses in a pigtail, and 6 or 7 metres of URM67 cable, and connectors).
In use on a flat field, using two of these antennae attached to pcmcia 802.11b cards via cable and pigtails, we were able to maintain an 11Mb/s network at between 400 to 500 metres with clear line of sight.
You may be able to tell from the lack of absolute measurments in my results that I do not have access to calibrated test equipment, or the time to carry out well documented tests. If anybody does, please let me know the results!
Article by Dave Gough at http://flakey.info/antenna/omni/quarter/
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