[CQ-Contest] band plan definition - LSB vs USB

Steve London n2icarrl at gmail.com
Thu Oct 4 12:20:01 EDT 2012

On 10/03/2012 07:04 PM, Tom W8JI wrote:
> - If my station is operating on USB, with a typical 3 dB transmit bandwidth of
> 2.7 kHz, then virtually all of the power of my fundamental emission is above my
> suppressed carrier frequency, and extends from my suppressed carrier frequency
> to at least 2.7 kHz above my suppressed carrier frequency.
> No.

What do you mean, "No" ?

Go back and reread what I said. Especially the part "at least 2.7 kHz above my 
suppressed carrier frequency". Your explanation completely validates what I 
said. You also conveniently edited-out my later paragraph, so I'll repeat it again:

- When you consider the shape factor of typical transmit filtering, and the 3rd
order IMD characteristics of SSB transmitters, the situation is actually much
worse than I have stated.

I won't put words in your mouth, but your reply really should have been, "Yes, 
but it's even worse than you stated".

Steve, N2IC

> The start frequency is the missing carrier + lowest audio tone passed.
> The stop is highest passed audio freq + the missing carrier.
> The FCC considers only the radiation, not the missing carrier, so with normal
> audio of 300-3000 it would be F+.3 to F+3, or with the dial set at 14.300 it
> would be 14.3003 to 14.303 plus any distortion or filter blow-through.The FCC
> doesn't care where the missing carrier is, so if 14.300 was segment or band end,
> it wiould be at least 3000 Hz out of band.

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