Re: LF: Re: 8kHz of spectrum

[M0FMT <m0fmt@yahoo.co.uk>]

Hi all

In my humble opinion high power only goes with wide band width because ground wave on these medium frequencies travels. So I welcome the lower power suggestion (assuming anybody sticks to it) with the narrow band width proposal. And don't jump on me about front end selectivity  because I think it is insurmountable even by "Real" Amateurs.

73 es GL Pete M0FMT IO91UX47VN

From: James Moritz <james.moritz@btopenworld.com>
To: rsgb_lf_group@blacksheep.org
Sent: Wednesday, 2 November 2011, 22:58
Subject: LF: Re: 8kHz of spectrum

Dear LF Group,

Well, I think this is a positive development - the only minor disappointment is the reduction in maximum ERP to about 3W.

As for the choice of frequency, the maritime people have a plan for a sort of  "super Navtex" using OFDM modulation with a bandwidth of 10kHz centred on 500kHz. It may be that this is just a pipe dream, and/or a way to justify continued primary user status at 500kHz. But if it ever does come into existence, it will certainly be using vastly higher powers than amateur stations, and the noise sidebands will extend well beyond the actual signal bandwidth due to "spectral re-growth" in the TX PA. So it will be good to have a significant difference in frequency between ourselves and the noisy things. I expect all those REAL amateurs will manage to reduce their TX frequency by 5 percent somehow ;-)

Cheers, Jim Moritz
73 de M0BMU