[hpsdr] eSSB for SDR's

[Glenn Thomas]

Hi all.

<FYI>

In the USA, transmission bandwidths are regulated by 97.307(a) of the 
FCC rules, which reads, "No amateur station transmission shall occupy 
more bandwidth than necessary for the information rate and emission type 
being transmitted, in accordance with good amateur practice." This is 
rather general. Based on the required bandwidth for a telephone 
conversation, which is somewhere between 2.7 and 3.0 KHz, the maximum 
bandwidth for an SSB emission (from a US station) is this same 2.7 to 3 
KHz. Likewise, for a full DSB AM signal, the same rule indicates to me 
that the maximum bandwidth is more like 6 KHz.

In my humble opinion, a 6 KHz wide eSSB signal violates 97.307(a) of the 
rules because the necessary bandwidth for a 'phone signal baseband is 
not more than 3 KHz and a 6 KHz SSB signal is more than this.

The US rule takes into account both information rate AND emission type, 
NOT bandwidth alone. I'm doing no more than applying what the rules say. 
The situation may be different in other countries, so your mileage may vary

</FYI>

An proposal was floated some years ago to regulate allowed signals based 
on bandwidth alone. This was shot down in flames by the Amateur 
community. Thus we in the US continue to be required to limit our 
bandwidths based on both the baseband information rate (3 KHz BW or so 
for 'phone) and the emission type (SSB or DSB).

If enough US Hams want to play with eSSB, perhaps it's time to start 
agitating for an FCC rule change to limit transmitted bandwidth strictly 
in terms of bandwidth and not consider emission type at all. Given that 
the 'phone subbands are allowed to have signals of AM bandwidth, eSSB 
signals of the same bandwidth would then be allowed. The downside, as 
pointed out by those who opposed regulation by bandwidth the last time 
it was proposed, is that digital signals of the same bandwidth (~6 KHz?) 
would then be allowed in the 'phone segments. A 6 KHz wide ODFM 
(digital) signal showing up on top of your eSSB QSO is not necessarily a 
good thing.

73 de Glenn wb6w



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