Topband: Inverted-L Bazooka type antenna

[Herbert Schoenbohm]

Charlie, WD5BJT asks:

 I have heard about an Inverted-L Bazooka type antenna that is a 1/4 wave
long. It is supposed to be lower in noise than the true  inverted-l.

IMHO there is little to gain, and nothing in the noise department from
making the flat top out of coax (Bazooka).

However a better approach to reduce some of the undesirable high angle
radiation from the horizontal portion of an inverted L  and provide
reasonable top loading is to fold the top wire back on it self. This can be
done with spaced insulators or even  ladder line. The voltage potential at
the top of the vertical portion is very high so the fold back material
depends also on the power level.

This approach allows for a shortened horizontal run which should be at least
around 1/8th wave long to force the current max near the top of the vertical
run.  This is a simple and effective Marconi type antenna which has been
widely used by the military on low frequencies in the past.

73

Herb Schoenbohm, KV4FZ