At 04:18 25/05/00 +0100, you wrote:
Can anyone provide a formula or graph showing the relative strength of
sidebands down to 80 kHz, please?
73 de
John Rabson G3PAI
John,
Official US Loran-C spec. states :
"Specification for energy distribution outside the 90-110 kHz band will be
achieved
if the spectral density of the radiated signal at 90 kHz and 110 kHz is
down at least
20 dB relative to its value at 100 kHz"
"Total spectral energy below and above the 90-110 kHz band shall be less
than 0.5%
each".
It is specified this way because the designers are only interested in
shaping the rising
edge of the pulse properly and don't much care how it decays. So the
spectrum
differs between transmitters and is not necessarily a smooth exponential decay.
That's why we have trouble at 136 kHz.
Walter G3JKV.
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