From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Tsutsumi Family" Subject: RE: 300bps Packet Date: Thu, 25 Nov 2010 19:43:06 +0900 Message-ID: <40C75B79D58C4ECDBC044010559CE8CA@LIVINGROOM> References: <4CEB5074.2070008@complete.org> <4CEB5C66.1050803@exemail.com.au> <6CE4D96A7B544D30919A49105B458915@LIVINGROOM> <4CEC16EF.8060106@radagast.org> <4CED5B60.5040108@radagast.org> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4CED5B60.5040108@radagast.org> Sender: linux-hams-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" To: 'Dave Platt' , linux-hams@vger.kernel.org Dave, Thank you for your quick reply. Along with Phill's configuration parameters i.e. f0=900Hz and f1=1,100Hz in the separate correspondence, the conclusion seems to be that f0 and f1 must be any arbitrary numbers below 1,200Hz and above the low cut frequency of his/her TX/RX audio path with 200Hz gap. As the above conclusion is unique nature of the soundmodem, the fact should be widespread to the new 300bps AFSK SSB users of the soundmodem and I hope Andrew's pointed sites will kindly cover this. Regards, take de JA5AEA -----Original Message----- From: linux-hams-owner@vger.kernel.org [mailto:linux-hams-owner@vger.kernel.org] On Behalf Of Dave Platt Sent: Thursday, November 25, 2010 3:37 AM To: linux-hams@vger.kernel.org Subject: Re: 300bps Packet 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. -- To unsubscribe from this list: send the line "unsubscribe linux-hams" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html