[time-nuts] Firmware and antenna for Stanford Research FS700 Loran C frequency standard

[Poul-Henning Kamp]

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In message <55A757D3.9050709 at mail.tele.dk>, Ole Stender Nielsen writes:

>I use a home-made untuned loop antenna [...]

A note about Loran-C and loop-antennas:

The loop-antennas are sensitive to magnetic fields and therefore
sensitive to direction.

Depending on side of the loop you point at the Loran-C transmitter
you will get a "true" or inverted signal.

If you get an inverted signal, a Loran-C receiver will lock onto
the wrong zero-crossing, which will increase your phase noise
because only the 3rd positive crossing is truly steered.

If you want to receive more than one Loran-C transmitter, the
directivity of the loop-antenna is a disadvantage and you are better
of with a monopole (electric) antenna.

I can recommend Chris Trasks designs:

	http://www.home.earthlink.net/~christrask/

I built one from the "Complementary Push-Pull Active Antenna Amplifiers"
document and it drags in signals from 4kHz to well north of 150Mhz.


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