From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Ranch Subject: Re: 300bps Packet (and EHAS) - what is pam, psk, and newpsk, Date: Thu, 25 Nov 2010 21:23:27 -0800 Message-ID: <4CEF444F.6010308@trinnet.net> References: <4CEB5074.2070008@complete.org> <4CEB5C66.1050803@exemail.com.au> <6CE4D96A7B544D30919A49105B458915@LIVINGROOM> <4CEC16EF.8060106@radagast.org> <4CED5B60.5040108@radagast.org> <40C75B79D58C4ECDBC044010559CE8CA@LIVINGROOM> <4CEEB394.3020305@trinnet.net> Mime-Version: 1.0 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: Sender: linux-hams-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="windows-1252"; format="flowed" To: Tsutsumi Family , linux-hams@vger.kernel.org Cc: 'Dave Platt' Hello Take, It's interesting you bring up the newQPSK setting. I've never found any= =20 comprehensive documentation on soundmodem and what some of these other=20 modes are. Do you know? Anybody else on the list know or could comment? fsk - I know what FSK is but what does it mean in respect to soundmodem= ?=20 My Yaesu FT-950 supports an FSK input and my US Interfaces Navigator=20 device does FSK too but how would soundmodem use it? Seems it's slowest= =20 speed is 4800Bits/sec. pam - what is pam? psk - I know what PSK is and I use the BPSK31 mode in Fldigi but what=20 would soundmodem do with it in respect to a packet mode? newqpsk - I know what QPSK is and I've used the QPSK31 mode in Fldigi=20 (has forms of FEC enabled on it) but what would soundmodem do with it i= n=20 respect to a packet mode? Seems it's slowest speed is 1000Bits/sec. I would love to learn what these modes do, are they stable, and maybe=20 these modes could be used as a strong alternative to trying/failing=20 300BAUD HF packet. --David > 900/1100 offset seems to a typical practice for the soundmodem 300bps > operation. > > I share your concern concerning it would not be the practical capabil= ity to > be used at HF. > > By the way, does anybody know the implementation status in the radio = amateur > world about EHAS (Hispano-American Health Link) protocol which is ori= ginally > based on radio amateur Linux AX.25 and the soundmodem of both FSK and > newQPSK modes but adds the several performance improvement techniques= like > FEC, Turbocodes, ARQ e.t.c.?=20 > > The several literatures can be googled by =93EHAS=94. > > Regards, > > take > > De JA5AEA > > ________________________________________ > From: David Ranch [mailto:linux-hams@trinnet.net]=20 > Sent: Friday, November 26, 2010 4:06 AM > To: Tsutsumi Family; linux-hams@vger.kernel.org > Cc: 'Dave Platt' > Subject: Re: 300bps Packet > > > I've used the same 900/1100 offset setting for 300baud HF packet with > Soundmodem and things worked OK I suppose. I ultimately came to the > conclusion (as did others in my research) that without a beam and hig= h > power, HF packet doesn't work very well. I would get four times more > retries than actual good packet exchanges from Santa Clara, CA to say= =20 > Denver, CO. (Google 'Network 105'). For this exact reason, I've been > tracking the Winmor efforts and it's upcoming kb-to-kb mode. I hope = one day > we'll see it on Linux where we can get a packet-like mode with real F= EC for > an inexpensive price. I now can now truly appreciate Pactor2/3 but t= he > beyond acceptable high costs of the single vendor TNC and the proprie= tary > nature of the mode are show stoppers for me. > > Anyway, I have my Soundmodem HF and VHF settings here: > > http://www.trinityos.com/HAM/CentosDigitalModes/etc/ax25/ > > > If anyone would like to put together a sched. (might be fun to try), = email > me.=20 > > --David > > > Tsutsumi Family wrote:=20 > Dave, > > Thank you for your quick reply. > > Along with Phill's configuration parameters i.e. f0=3D900Hz and f1=3D= 1,100Hz in > the separate correspondence, the conclusion seems to be that f0 and f= 1 must > be any arbitrary numbers below 1,200Hz and above the low cut frequenc= y 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: > =20 > 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 =3D1,200 Hz such as 800Hz and 1,000Hz, not conventional 2,100H= z and > 2,300Hz. > > Correct? > =20 > > 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 > > -- > 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 > =20 > > -- > 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 > =20 -- To unsubscribe from this list: send the line "unsubscribe linux-hams" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html