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Subject: Re: Possibly incorrect FM region settings

Re: Possibly incorrect FM region settings

From: Bertrik Sikken <bertrik_at_sikken.nl>
Date: Sun, 04 Jan 2009 12:20:54 +0100

Alessio Lenzi wrote:
> "Mike Holden" <rockbox_at_mikeholden.org> wrote:
>> boundary where it can be squeezed in.", suggesting that this is not
>> exclusively Italy, but possibly other countries as well.
>
> european standard is 50, also the official Sansa's E200 firmware, by
> setting Europe, lets skip 50 MHZ only.
> Besides I bought a radio receiver in Hong Kong, not in Italy, setting
> european region, step put automatically 50 MHZ.
> In my opinion Rockbox doesn't need any changes to radio region's settings.

Do you have a reference for the 50 kHz standard? (I don't think some
radio bought in Hong Kong qualifies as a reference).

In addition to what wikipedia says about the discontinuation of 50 kHz
channels, recommendation BS412 from the ITU-R (International
Telecommunication Union - Radiocommunication sector) says:
"the carrier frequencies which define the nominal placement of the RF
channels within the band are integral multiples of 100 kHz;"
Also have a look at the frequencies used by European FM stations at
fmlist.org : stations are spaced at 100 kHz intervals and stations
using 50 kHz are extremely rare.

How about the following settings:
Europe: 87.5 - 108.0 MHz, 100 kHz steps, 50 us de-emphasis
US / Canada: 87.9 - 107.9 MHz, 200 kHz steps, 75 us de-emphasis
Japan: 76.0 - 90.0 MHz, 100 kHz steps, 50 us de-emphasis
World: 87.5 - 108.0 MHz, 50 kHz steps, 50 us de-emphasis

This isn't actually a big change, basically the old 'Europe'
setting with 50 kHz spacing is now called 'World' and the old
'Korea' setting with 100 kHz spacing is now called 'Europe'.
In most of Europe, people can now select the 'Europe' setting instead
of having to choose the 'Korea' setting for optimum performance,
except for Italy which uses the 'World' setting.

I think I'll create a patch for this proposal and put in on the
flyspray tracker.

Kind regards,
Bertrik
Received on 2009-01-04


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