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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: Tue, 30 Dec 2008 01:55:57 +0100

Mike Holden wrote:
> Bertrik Sikken wrote:
>> Hi all,
>>
>> While working with the rockbox radio code a bit I noticed that currently
>> the FM channel spacing for the 'europe' FM region setting is 50 kHz.
>> (see fm_region_data in firmware/tuner.c)
>> I think this should be 100 kHz.
>>
>> The 100 kHz spacing for europe is mentioned in the si4702 radio chip
>> datasheet and wikipedia ( http://en.wikipedia.org/wiki/FM_band ) also
>> mentions "An ITU Geneva conference of 1984-12-07 resolved to discontinue
>> the use of 50 kHz offsets throughout Eastern and Western Europe."
>> Here in the Netherlands, all FM frequencies are on a 100 kHz spacing.
>> This is also the case for France and Germany as far as I could find in
>> a quick search with google. According to wikipedia, Italy is apparently
>> an exception, still using 50 kHz for some stations.
>
> The wikipedia reference actually says "Some countries, such as Italy which
> has a heavily-congested FM band, still allow a station on any 50 kHz
> boundary where it can be squeezed in.", suggesting that this is not
> exclusively Italy, but possibly other countries as well.
>
> I would personally suggest that unless we can show for definite that Italy
> is the __only__ exception country, it may be unwise to make a global
> change?

The wiki text suggests that Italy (and possibly others) is an exception
rather than the norm. The current setting makes all of Europe suffer for
the countries that are the exception, rather than the other way around.

Your suggestion means that nothing will change until someone does an
exhaustive search of all stations in all european countries (any
volunteers?) to see if there are more countries with stations that
deviate from the standard. In the meantime, FM settings are sub-optimal
for the majority of Europe.

I have a zipfile with station pdfs with a list of all stations for each
country in europe, north africa and the middle east (10s of thousands).
Browsing through this list shows that the 50 kHz spacing is extremely
rare (e.g. a tv sound channel in Albania is on the very low end of the
FM band at a xxx.x50 frequency), except in Italy.

Kind regards,
Bertrik
Received on 2008-12-30


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