[Elecraft] K3: CW feature request

[Alan Bloom]

On Wed, 2009-12-02 at 21:06 -0800, Alan Bloom wrote:
> On Wed, 2009-12-02 at 18:36 -0800, wb6rse1 at mac.com wrote:
> > LSB on the lower bands and USB on the higher bands is an artifact of  
> > the mixing scheme, from the early days of SSB, of a 9 Mc IF mixed with  
> > a 5.0 - 5.5 Mc VFO. (Yes, it was Mc in those days, not MHz.) Add and  
> > you get 20m. Subtract and you get 80m. The subtraction results in  
> > sideband reversal and so LSB became the "standard" for 80m. There is  
> > really no reason now to not to just operate USB on all bands other  
> > than tradition.
> 
> I've heard people say that many times over the years but clearly it's
> not true.  A 9 MHz IF set up for (let's say) USB will still be USB no
> matter whether you add or subtract the 5-5.5 MHz VFO.

I just did a little Googling on the Internet (AC6V.com and elsewhere)
and discovered to my astonishment that this is an actual bona-fide
controversial subject among radio amateurs.  Despite the fact that a
simple 2-minute back-of-the-envelope calculation is all it takes to
disprove the myth.  For the record:

Intermediate frequency:
Carrier   9.000 MHz
Sideband  9.001 MHz
==> USB

Add 5 MHz VFO:
Carrier   9.000 + 5.000 = 14.000 MHz
Sideband  9.001 + 5.000 = 14.001 MHz
==> USB

Subtract 5 MHz VFO:
Carrier   9.000 - 5.000 = 4.000 MHz
Sideband  9.001 - 5.000 = 4.001 MHz
==> USB

I can't believe people are actually arguing about this!

Al N1AL