[Elecraft] K3 - ESSB Availability

Paul Christensen w9ac at arrl.net
Thu May 29 11:08:58 EDT 2008


> Every time I see the term ESSB I see red.  I wonder if these folks have 
> ever read FCC Part 97.307 (a) Emission Standards:
>
> (a) 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.

Bill,

The problem with Section 97.307(a) lies in its drafting and purpose.  The 
plain-language meaning of this section infers that as long as the 
transmission occupies no more bandwidth than that necessary for the emission 
type we are trying to achieve, then we are complaint with the rule, subject 
to "good amateur practice."

For example, suppose my intent is to use ITU designator 3K00J3E (i.e., 3 kHz 
SSB bandwidth).  My intent is to use 3 kHz of occupied bandwidth and 
clearly, the ITU designator sets the "emission type" as stated in the 
aforementioned rule.  Taking this one step further, if my desired occupied 
bandwidth is 3 kHz under the ITU 3K00J3E designator, then as long as I 
remain within that boundary I have set for the "emission type being 
transmitted," I am fully-complaint with the rule (see my bandwidth boundary 
caveat at the end).

In fact, suppose I wish to transmit with 6 kHz of SSB bandwidth and my 
desired emission type is 6K00J3E under the ITU designator.  Pursuant to the 
rules, that transmission can be fully-complaint as well.  However, this also 
presumes that any such transmission -- no matter what the actual 
bandwidth -- does not cause interference to existing transmissions.  Whether 
the actual transmitted bandwidth is 1.8 kHz of 6 kHz, there's always a 
propensity to cause some interference to existing transmissions.

Moreover, terms like "good amateur practice" and "information rate" should 
never be codified into rules & regulations unless these terms are 
incorporated by reference into definitions in the preamble of the rules. 
Only, the original framers of Sec. 97.307(a) likely wanted to keep this 
section open for experimentation purposes without the necessity of placing 
hard bandwidth restrictions on emissions that could otherwise thwart the 
benefits of experimenting with various modes that exist today -- and those 
modes that may become developed at some point in the future.  Enforcement of 
97.307(a) would never, and could never, stand up to Constitutional scrutiny 
on the basis of the rule's arbitrary, capricious, and vague drafting.

Another problem that surfaces when we establish hard occupied bandwidth 
rules is the necessity to monitor the bandwidth of emissions (to ensure 100% 
compliance) and the lack of a reasonable means for the average licensee to 
measure such.  Also, codified bandwidth regulations would require setting 
measurement limits at the spectrum edges.  For example, at what point is a 
3K00J3E no longer compliant?  Perhaps at -26 dB Peak Power?  - 50 dB Peak 
Power?   It gets real messy, real fast.

Paul, W9AC

 



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