[Elecraft] Which sideband on data mode?

[Joe Subich, W4TV]

> Years ago,  MMTTY for FSK assumed USB reception for polarity. 
>   If guys were trying to receive your FSK signal on LSB, it was 
> inverted.

MMTTY handles FSK on LSB just fine and has done so nearly forever. 
It simply requires one set the mark to 2125 and - assuming one 
is using an interface with open collector transistor FSK output 
- configuring the transceiver so that Mark represents a low 
(closed) on the FSK input. 

It is a shame that so many authors of digital software are simply 
too lazy to support operation on either sideband and ignore the
long history of LSB for AFSK.  Use of USB as a "standard" sideband 
for digital modes is only an artifact of the software that does 
not work with LSB.  

73, 

   ... Joe, W4TV 
  




> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net 
> [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Brian Alsop
> Sent: Saturday, August 23, 2008 11:55 AM
> To: elecraft at mailman.qth.net
> Subject: Re: [Elecraft] Which sideband on data mode?
> 
> 
> I don't know if it is still the case. 
> Years ago,  MMTTY for FSK assumed USB reception for polarity. 
>   If guys 
> were trying to receive your FSK signal on LSB, it was 
> inverted.  There 
> was no software switch to invert the polarity either.
> 
> Perhaps this has been resolved by now.
> 
> 73 de Brian/K3KO.
> 
> Simon (HB9DRV) wrote:
> 
> > In Europe at least I only see USB for RTTY - but don't 
> watch too much
> > RTTY anyway.
> >
> > Simon Brown, HB9DRV
> > www.ham-radio-deluxe.com
> >
> > ----- Original Message ----- From: "R. Kevin Stover" 
> > <rkstover at mchsi.com>
> >
> > The "standard" is USB for digi modes like PSK, MFSK, all the others 
> > except RTTY. The convention for RTTY is LSB The K2 will do 
> either USB 
> > or LSB. Technically it doesn't really matter. A PSK signal 
> sent with 
> > USB can be decoded with LSB and visa versa.