From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Markowski Subject: soundmodem parameter definitions Date: Fri, 20 Feb 2004 09:40:37 -0500 Sender: linux-hams-owner@vger.kernel.org Message-ID: <20040220144037.GQ14329@strauss.udel.edu> Mime-Version: 1.0 Return-path: Content-Disposition: inline List-Id: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Linux Hams I have a few simple soundmodem questions that I couldn't answer using Google, and I haven't yet dug into the code. In soundmodemconfig (using v0.7) I'm trying to get a better understanding of the parameters: txDelay: is this the delay between asserting PTT and start of data transmission? (My set up with an ICOM 706 MkIIg didn't work until increasing txDelay to 400 ms) txTail: delay from end of transmission till deasserting PTT? I'm using the default 10 ms and my aprs UI packets are being received by others. slot time: this one confuses me. I know what traditional slotted channels are, but it doesn't make sense that a user would pick the slot length. So I'm guessing this is something different. Is the default of 100 ms reasonable? I used 300 ms for no special reason... pPersistence: I assume this is used by the CSMA backoff algorithm. Would I ever want to change the default of 40? And on a completely unrelated note, if anyone knows of any packet frequencies to use on HF or in southeastern Pennsylvania, please let me know. So far I've only been able to use APRS for testing. The only other nodes I've found locally are FlexNet BBSes, which I don't know much about except that they reply to SABM+ connection requests with RR0+ and next with a long packet my soundmodem never seems to decode. But maybe that's because my txTail or slot time are poorly chosen... I still have a lot to figure out. Thanks! I really appreciate all the great help to beginners from this list. Mike AB3AP