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On 15 Feb 2005 22:51:30 -0800, wrote:

I have seen discussion of topfed dipoles as antenna and recognise that
they have two 'features': 1 They are are frequency specific 2 they are
directional.

However I have seen decriptions of off-centre-fed dipoles with baluns
that cover all ham bands, I have not seen numbers for their performance
on other frequencies. It seems to me that these would be a very
convenient solution; a 4:1 balun at the masthead fed by coax and
feeding (eg) forestay and backstay with appropriately placed
insulators.

Comments ?

A 4:1 balun is only good to transform 200 ohms to 50 ohms if you are
using 50 ohm coax. If the antenna is not 200 ohms then the balun is
worse than if it were not there.

Regards
Gary