[Lf] LORAN sidebands]

[Andre' Kesteloot]

Walter Blanchard wrote:

> 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.