What do I do, however, for those frequencies for which it is close
to a half wave? PI network? Or L network?

===================================

You very slightly de-tune (decrease) the antenna length, not enough to have
any effect on its radiating properties, such that a simple parallel tuned
matching circuit will cope.

You can connect a coax feedline line either in series with the coil, an
L-network. or tap the coax a few turns up the coil. A very modest ground
connection adjacent to the bottom end of the coil witll suffice.

The same circuit will cater efficiently for quite a wide range of antenna
heights.

I hope you are satisfied with the above description.
---
Reg, G4FGQ

I'm never satisfied, always driven by the spirit
of curiosity and discovery!

Changing the vertical length is not an option as its
an ally pole supporting a tv antenna; it just happens to be insulated
from the ground.

I was planning to put about 20 radials in green-and-yellow, splaying
out from a single copper stake.

"Reg Edwards" wrote in message
...
What do I do, however, for those frequencies for which it is close
to a half wave? PI network? Or L network?

===================================

You very slightly de-tune (decrease) the antenna length, not enough to
have
any effect on its radiating properties, such that a simple parallel tuned
matching circuit will cope.

You can connect a coax feedline line either in series with the coil, an
L-network. or tap the coax a few turns up the coil. A very modest ground
connection adjacent to the bottom end of the coil witll suffice.

The same circuit will cater efficiently for quite a wide range of antenna
heights.

I hope you are satisfied with the above description.
---
Reg, G4FGQ