[hpsdr] eSSB for SDR's

[Sid Boyce]

The regulations in the UK are pretty much the same.
Going to eSSB suggests forgetting one of the key reasons why AM fell by 
the wayside and eSSB seems to be a return to AM under another guise as 
far as bandwidth is concerned.

There is no more information exchanged by using eSSB, the guy using SSB 
is not at a disadvantage to the guy talking to him using eSSB nor is the 
guy transmitting eSSB and listening to the other guy using SSB.

There are guys using eSSB causing splatter to other users of the bands, 
same for guys sounding worse and more difficult to listen to using 
various maladjusted audio "enhancing" gear.

I can copy SSB with no problems, eSSB IMHO seems to be an unnecessary 
fetish that does nothing for the listener but pollutes the space of a 
listener on an adjacent channel.

I could understand it if they were trying to make more efficient use of 
the 3KHz bandwidth allowed - as is the idea of normal speech processing.
73 ... Sid.

On 26/08/12 09:34, Glenn Thomas wrote:
> ***** High Performance Software Defined Radio Discussion List *****
>
> 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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-- 
Sid Boyce ... Hamradio License G3VBV, Licensed Private Pilot
Emeritus IBM/Amdahl Mainframes and Sun/Fujitsu Servers Tech Support
Senior Staff Specialist, Cricket Coach
Microsoft Windows Free Zone - Linux used for all Computing Tasks


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