From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Platt Subject: Re: 300bps Packet Date: Wed, 24 Nov 2010 10:37:20 -0800 Message-ID: <4CED5B60.5040108@radagast.org> References: <4CEB5074.2070008@complete.org> <4CEB5C66.1050803@exemail.com.au> <6CE4D96A7B544D30919A49105B458915@LIVINGROOM> <4CEC16EF.8060106@radagast.org> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-hams-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" To: linux-hams@vger.kernel.org Tsutsumi Family wrote: > Dave, > > Thank you for providing the tutorial of SM source codes. > > As one of ways to solve 300bps SSB operation without any code change, you > are suggesting to use the frequency setting of f0 and f1 to less than 4 x > 300bps =1,200 Hz such as 800Hz and 1,000Hz, not conventional 2,100Hz and > 2,300Hz. > > Correct? Correct - I think this ought to work. As long as you don't pick frequencies so low that your audio connection (PC to rig) is rolling off the amplitude (due to e.g. transformer isolation in the audio path) this approach should let you generate a pair of tones with a suitable separation. You'll just need to tune your sideband rig a bit differently than if you were using a traditional "hard" TNC with its receive filters tuned for a 2200 Hz channel center. Just tune to match up the tone you hear during reception, with the tone that your PC generates during transmission... it'll be an octave or so lower than the usual pitch but it should work.