Re: NEC-LIST: Anyone have impedance data on typical loran-c whip?

Hi Ed,

Loran works at low frequencies, as you know. This means that for optimum
reception, you need maximum voltage, not maximum power transfer. It is
usual to terminate the high R ,low C, and high impedance whip antenna with
an even higher impedance receiver input impedance, to minimise the voltage
drop due to the antenna impedance. Is there another reason for requesting
the impedance ? What matters is signal-to-noise ratio.

Ed Troy wrote:
>
> I have been calling all over the place, and searching all around, and
> nobody seems to have any clue as to what the typical impedance is for a
> loran-c whip. I know they range from about 18 inches to about 8 feet
> (typically an 8 foot whip, at least for marine purposes), but that is all
> anyone seems to know. I assume they are spirally wound around a fiberglass
> core, of some sort, but I am not sure about that, either. One person
> speculated that they look like 20k to 50K ohms resistive in parallel with
> about 30 pf, but I have no idea if that is accurate. I know the antennas
> are highly capacitive, since they work at 100 kHz, but I would love to find
> out more detail about what the actual impedance of a loran-c whip antenna
> is. Does anybody on the list have that info?
> --
> The NEC-List mailing list <nec-list_at_gweep.ca>
> http://www.gweep.ca/mailman/listinfo.cgi/nec-list

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