[time-nuts] eLoran test 6 Feb for almost 2 months

Poul-Henning Kamp phk at phk.freebsd.dk
Fri Feb 3 13:38:39 EST 2017

In message <CAD2JfAjSGrpoj5TJtB7uNeoAPng5zJUKLCJM2Kkgfp-pD8aOTA at mail.gmail.com>, paul swed writes:

>John absolutely 1 frequency 100 KHz. The repetition rate is 89700 us. Its
>pulse and you need about +-15KHz BW. If listening its just a ticking sound.

Instead of your SDR it might be smarter to use either a digital
oscilloscope or spectrum analyzer.

You will need a frequency of *exactly* 1/0.089700 us = 11.14827201... Hz.
(HP5359A's are *great* for this, but most DDS sig-gens will work too.

You use this to signal to trigger your scope/spectrum analyzer, feed the
antenna signal to the input and select averaging mode.

If you have a really good antenna signal and a scope/spec-an with high
X-resolution, you can halve the sync frequency and, so that the pulse
polarity does not cancel out about half the loran pulses.

Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.

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