Thread: Standing waves
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Old September 22nd 09, 07:36 PM posted to rec.radio.amateur.antenna
Szczepan Białek Szczepan Białek is offline
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Default Standing waves


"Richard Fry" wrote
...
On Sep 22, 2:21 am, Szczepan Białek wrote:

It apply to 1/2WL dipole. But what radiate in 0.05WL dipole? There the

"maximum radiation " is in the transmission line (1/4WL from the end).
The feed point is also in the transmissing line.


There is no radiation from a transmission line as long as the currents

in it are balanced. Attaching a transmission line to a 0.05WL center-
fed dipole does not change that balance.

The feedpoint of such a short dipole has very high capacitive

reactance, so getting much current to flow into it would be difficult
without proper impedance matching to the transmission line.

The feed point is the part of the transmissing line and not radiate.

But whatever the impedance match, all of the radiation occurs from the

0.05WL dipole itself, and maximum radiation is generated at the
feedpoint, where the r-f current is greatest.

See above.

Dipole 0.05 is probably the straight. How long are the folded dipoles and
the loop antennas? Are there the short version?
S*