On Sat, 14 Feb 2004 11:08:39 -0000, "Richard"
wrote:

Hi. Is there a standard way to measure antenna bandwith? Is it within 3dB
down of maximum gain, or is it between SWR limits?

I'm looking at an FM receiving yagi that is advertised as covering the
frequency range 87.5 - 108 Mhz. And I'm wondering what this means. Is the
received signal going to be 3dB down at the band edges or what?

I notice that there are commecial yagis (that are probably suitable for
transmission) that have 150-174 Mhz in their description. Yet they are
stated as having a bandwidth of say 1.3 Mhz. What's the deal here?


They are usually showing you that these antennas are available
anywhere in that frequency range but you have to specify what 1.3 mhz
part you actually want. The antenna will be cut to operate only in
that 1.3 mhz range. It is usually swr band width that it is specked
at. Gain band width may be different.

73
Gary K4FMX