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Old October 15th 07, 09:42 PM posted to rec.radio.amateur.antenna
Richard Clark Richard Clark is offline
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Default Antenna for receiving WWV/10MHz: am I asking too much?

On Mon, 15 Oct 2007 19:48:48 GMT, Gene Fuller
wrote:

However, the combined efficiency of the two antennas
is about 65%. As a result, each transmitter only has to
produce a forward power of about 38 kW for WWVB to
produce its effective radiated power of 50 kW."


The NIST folks could probably increase the efficiency to greater than
90% if they dug a large pit to temporarily store the decaying electrons.
All of those dying electrons lying on the ground tend to discourage the
active electrons from working as hard as they could.

The efficiency could be raised to nearly 100% if the two helices were
wound in opposite directions. That would provide the best shot at
equilibrium.


Hi Gene,

You shave points too close. They could achieve 130% efficiency if
they simply tapped into the current return on the inside of the wire.

Arthur's 3dB here and 3dB there, if you use enough wire, then you are
beginning to talk about GAIN!

Also, Fort Collins is a higher altitude than Podunk Illinois, so
impedance is less than 377 Ohms too! High gain, maybe 129% efficient.

***** irony mode off ********

Load resistance seen by the transmitters is roughly 0.85 Ohm
transformed to 50 Ohms.

73's
Richard Clark, KB7QHC