LF: Re: SSB - why not go digital? Have a look at FDMNV

["Chris" <c.ashby435@btinternet.com>]



Hi Geri,

Thanks for that idea/information. I guess there are possibilities with this method for narrow AM as well. Definitely worth looking into.

Vy 73, Chris, G4AYT.

----- Original Message -----

From: geri@dk8kw.de

To: rsgb_lf_group@blacksheep.org

Sent: Thursday, January 03, 2013 8:47 AM

Subject: LF: SSB - why not go digital? Have a look at FDMNV

Hi,

I just did some research and obviously there are people who already have thought about low bandwidth voice communications. There is a mode called FDMNV, based on a common CODEC that transmits voice in a 1100 Hz bandwidt (see http://n1su.com/fdmdv/).

In the describtion of the software it says "it caters to high quality digital voice under poor band conditions, in only 1100Hz bandwidth" which probably is the kind of features we are looking for. The software is open source and surely worth to have acloser look at. 

Also, i am sure we (in Germany) can negotiate with our authorities to get an extension of our 800 Hz bandwidth limitation at least under certain conditions. For everyone without limitation this seems to be the software to just go ahead and try it!

Best 73

Geri, DK8KW

> > ----- Original Message -----
> > From: M0FMT
> > To: rsgb_lf_group@blacksheep.org
> > Sent: Thursday, January 03, 2013 12:30 AM
> > Subject: Re: LF: 477 A local SSB chat band ?
> >
> >
> > Hi Graham Geri and all
> >
> > Warren has seen SSB first hand on the MF QRG and we have this side also.There was an SM station (call sign forgotten?) in the early days of 500 that added an SSB anouncement on his beacon and it worked well.
> >
> > To my spec. :- "One SSB channel at the high edge of the band only used during daylight hours no DXing!" add " Use VOX, no monologuing allowed" to be a laissez faire operation no band plan, but fair play!.73 es GL es HNY Pete M0FMT IO91UX
> >
> > From: Graham <g8fzk@g8fzk.fsnet.co.uk>
> > To: rsgb_lf_group@blacksheep.org
> > Sent: Wednesday, 2 January 2013, 20:48
> > Subject: Re: LF: 477 A local SSB chat band ?
> >
> >
> >
> > Geri
> >
> > 800 Hz B/W ... May be this is something 'Wolf' can code for you ? a b/w compression / expansion module in SL , to limit the tx b/w to 800 Hz must be possible to divide by 3 and mult by 3 with a linear shift as well ?
> >
> > G..
> >
> >
> > From: Holger 'Geri', DK8KW - DI2BO - W1KW
> > Sent: Wednesday, January 02, 2013 8:36 PM
> > To: rsgb_lf_group@blacksheep.org
> > Subject: Re: LF: 477 A local SSB chat band ?
> >
> >
> > Hi,
> >
> > I kind of like the idea of an SSB channel. I just pulled out the conditions of my first secial license for 160m from 1973 or 1974. That said 1815 to 1835 kHz with 10 Watts in CW, additionally one SSB channel for 1832 to 1835 kHz, so why not trying this on 630m, too? Here in Germany we are currently limited to 800 Hz bandwidt but I am sure we can sork towards a special license under certain conditions such as daylight operation only .. sounds good to me!
> >
> > Vy 73
> >
> > Geri, DK8KW
> >