RE: [digitalradio] Using 8FSK ARQ in PCALE (Re: ALE QRM is minimal)
Rick and all, Yes...that's probably correct. I guess what I am really asking (as you are?) what modulation technique works best on HF. This may be a balance between the maximum number of bits you can get off of one carrier (tone) vs. how robust it is. There will surely be trade offs. But we need to come to some consensus concerning how robust we want a data mode to be and what user thought we want. Also, we probably need to divide data modes between keyboard-to-keyboard (chat) modes, Broadcast modes and messaging modes. I suspect that each classification will have a different optimum mode and the robustness and throughput desires will be different. Here's my view...desired specifications: ModeRobustness *User Throughput Chat-10 dB SNR 60-200 WPM ASCII Data-10 dB SNR 800-~ WPM ASCII plus binary equivalent Messaging -5 dB SNR 800-3000 WPM plus binary equivalent * on a Poor CCIR Channel 73, Walt/K5YFW -Original Message- From: digitalradio@yahoogroups.com [mailto:[EMAIL PROTECTED] Sent: Wednesday, August 30, 2006 7:12 PM To: digitalradio@yahoogroups.com Subject: Re: [digitalradio] Using 8FSK ARQ in PCALE (Re: ALE QRM is minimal) Walt and group, My understanding is that the 64QAM mode of the DRM programs being used by SSTV operators does not work well on HF frequencies unless you have near perfect conditions. What are the opinions on the how well multipath and difficult conditions are handled by these different modulation techniques? Also comparing with QAM and OFDM. 73, Rick, KV9U DuBose Walt Civ AETC CONS/LGCA wrote: Why not run 64 tones with FSK at 50 baud or 64 tones with OQPSK at 50 baud? Shucks, for that matter how about 128 tones using QAM64 at 50 baud? Walt/K5YFW Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
RE: [digitalradio] Using 8FSK ARQ in PCALE (Re: ALE QRM is minimal)
Why not run 64 tones with FSK at 50 baud or 64 tones with OQPSK at 50 baud? Shucks, for that matter how about 128 tones using QAM64 at 50 baud? Walt/K5YFW -Original Message- From: digitalradio@yahoogroups.com [mailto:[EMAIL PROTECTED] Sent: Tuesday, August 29, 2006 7:06 PM To: digitalradio@yahoogroups.com Subject: [digitalradio] Using 8FSK ARQ in PCALE (Re: ALE QRM is minimal) As a convenience, many of the amateur radio ALE operators with PCALE have been using the built-in 8FSK modem for texting. It uses the same 8 tones and baud rate that the main ALE part of the system uses for calling. For keyboarding/texting, we often use the feature called DTM (Data Text Message) with ARQ. We also sometimes use the other feature called DBM (Data Binary Message) with ARQ for sending files, or images. Both DBM and DTM normally run at 125 baud. It would be great to see an amateur radio version of it developed with the same 8 tone set that simply runs at 1/4 speed, to be used when propagation conditions are marginal. Bonnie KQ6XA Steve N2CKH wrote: Get a copy of PC-ALE and single channel just establish a link between you and another station and then fire off a DBM BRD or ARQ message, there are settings for number of retries and maximum frame size, with DBM supporting binary data there is also a DBM FTP selection for sending files. The speed is always fixed at maximum. /s/ Steve, Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [digitalradio] Using 8FSK ARQ in PCALE (Re: ALE QRM is minimal)
Walt and group, My understanding is that the 64QAM mode of the DRM programs being used by SSTV operators does not work well on HF frequencies unless you have near perfect conditions. What are the opinions on the how well multipath and difficult conditions are handled by these different modulation techniques? Also comparing with QAM and OFDM. 73, Rick, KV9U DuBose Walt Civ AETC CONS/LGCA wrote: Why not run 64 tones with FSK at 50 baud or 64 tones with OQPSK at 50 baud? Shucks, for that matter how about 128 tones using QAM64 at 50 baud? Walt/K5YFW Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[digitalradio] Using 8FSK ARQ in PCALE (Re: ALE QRM is minimal)
As a convenience, many of the amateur radio ALE operators with PCALE have been using the built-in 8FSK modem for texting. It uses the same 8 tones and baud rate that the main ALE part of the system uses for calling. For keyboarding/texting, we often use the feature called DTM (Data Text Message) with ARQ. We also sometimes use the other feature called DBM (Data Binary Message) with ARQ for sending files, or images. Both DBM and DTM normally run at 125 baud. It would be great to see an amateur radio version of it developed with the same 8 tone set that simply runs at 1/4 speed, to be used when propagation conditions are marginal. Bonnie KQ6XA Steve N2CKH wrote: Get a copy of PC-ALE and single channel just establish a link between you and another station and then fire off a DBM BRD or ARQ message, there are settings for number of retries and maximum frame size, with DBM supporting binary data there is also a DBM FTP selection for sending files. The speed is always fixed at maximum. /s/ Steve, Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
