[CQ-Contest] Band edge operating - Previously "More CQWW SSB spot analysis"

[Michael Keane K1MK]

At 09:27 PM 11/2/2007, Paul Cassel wrote:
>You will note that in the IARU bandplan, the top end of the 20 metre band is
>as everyone agrees 14350,

In this case, 14350 kHz is not just a good idea (or agreement), it's 
the law. :-) Law that is binding upon signatories (countries) via 
treaty obligation.

>however also note it shows an authorized maximum
>bandwidth of 2700 Hz.  So interpretation by each country and regulator
>becomes an objective one.

The principle originates in Article 4 of the Radio Regulations of the 
International Telecommunication Union: "4.5 - The frequency assigned 
to a station of a given service shall be separated from the limits of 
the band allocated to this service in such a way that, taking account 
of the frequency band assigned to a station, no harmful interference 
is caused to services to which frequency bands immediately adjoining 
are allocated."

I'll agree that exactly what constitutes harmful interference to 
services on the frequencies immediately adjoining frequencies 
allocated to the amateur radio service is subject to interpretation. 
While I could see merit in arguments for operating as close as 2.1 
kHZ, 2.7 kHz, 3.0 kHz, etc. from the band edge, operating on a 
frequency that places most or all of one's transmitted signal outside 
the amateur allocation is going too far and is objectively wrong.

All amateurs radio operators have the responsibility of ensuring that 
their transmitted signal is contained within frequencies allocated to 
the amateur radio service.

>I expect only the US FCC Part 97 is worded to
>specifically limit any modulation content to be within the band edges??

 From a very cursory search, similar language does also appear in the 
Australian and South African rules.

That the transmissions from stations operating in the amateur service 
must be confined to the frequencies allocated to the amateur radio 
service may be a point that some administrations feel is simply too 
obvious to have to state explicitly in their rules.

73,
Mike K1MK

Michael Keane K1MK
k1mk at alum.mit.edu