The pulses have a width of either 100, 200 or
300us. The time/date is carried by pulse width mod :100ms = 0, 200ms = 1, with a framing code at the
52 - 59 second interval of '01111110'. Parity checks and DUT info are
carried in a 'second level' pulse during the framing code, so some of the pulses
are extended from 200 to 300ms. The seconds marker is 500ms
long.
So...
Your answer is that all pulses are a multiple of 1/
(10Hz) hence there is a sin(x) /x pattern is based on 10Hz and 5Hz
convolved with the 1Hz PRF
Andy G4JNT
----- Original Message -----
Sent: Tuesday, April 11, 2006 5:22
PM
Subject: Re: LF: Rugby LORAN
measurement?
Peter Martinez wrote:
The design of an MSF receiver, intended to recover the carrier frequency to
any great accuracy, needs to be able to reject the existing 'unwanted'
signals either side of the carrier. These are only about 15dB down and at
+/-1Hz. I am referring to the 1 sec timing pulses (gaps).
[snip
Just for fun I displayed the spectrum of Rugby 60 kHz
as received here, shifted to 1000 Hz :
My question
is : why is the sideband corresponding to the tenth harmonic of the 1pps pulse
almost zero ? Does this depend on the specific duty cycle of the modulating
pulses ?
Just curious...
73 Alberto I2PHD
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2006-04-11
