From 0a6a78a4db9ac356d3511914f8f1e95d849fee77 Mon Sep 17 00:00:00 2001 From: drowe67 Date: Mon, 14 Sep 2015 11:03:37 +0000 Subject: [PATCH] some user guide doco on Voice Keyer git-svn-id: https://svn.code.sf.net/p/freetel/code@2329 01035d8c-6547-0410-b346-abe4f91aad63 --- freedv-dev/README.txt | 92 ++++++++++++++++++++++++++++++++----------- 1 file changed, 68 insertions(+), 24 deletions(-) diff --git a/freedv-dev/README.txt b/freedv-dev/README.txt index b0b90eb0..648181a1 100644 --- a/freedv-dev/README.txt +++ b/freedv-dev/README.txt @@ -203,6 +203,8 @@ TODO + shouldn't trigger sync logic, will be a problem with carriers [ ] "clip" led, encourage people to adjust gain to hit that occ when speaking [ ] Win32 record from radio time + [ ] Stuttering with squelch off + + Rpeorted by Mark VK5QI, can we repeat? [ ] FreeDV 700 improvements [ ] bpf filter after clipping to remove clicks @@ -219,6 +221,12 @@ TODO [ ] switchable diversity (narrowband) option + measure difference on a few channels + blog + [ ] slow mode at half speed rather than repeating, or tx twice and sum + [ ] Can freedv remove ambient rf with a simple second Rx? + [ ] presence, posting to web site + [ ] explore relaxing sync 700 thresh + [ ] longer record files + [ ] two vertical lines in the waterfall representing the band limits of the 700B mode [X] win32 [X] X-compile works @@ -254,27 +262,63 @@ TODO USER GUIDE NOTES ================= -TODO: Put this in a more usable form, video tutorials etc - -1/ Error Histogram. Displays BER of each carrier when in "test frame" - mode. As each QPSK carrier has 2 bits there are 2*Nc histogram - points. - - Ideally all carriers will have about the same BER (+/- 20% after 5000 - total bit errors). However problems can occur with filtering in the - tx path. If one carrier has less power, then it will have a higher - BER. The errors in this carrier will tend to dominate overall - BER. For example if one carrier is attenuated due to SSB filter - ripple in the tx path then the BER on that carrier will be higher. - This is bad news for DV. - - Suggested usage: Transmit FreeDV in test frame mode. Use a 2nd rx - (or get a friend) to monitor your rx signal with FreeDV in test frame - mode. Adjust your rx SNR to get a BER of a few % (e.g. reduce tx power, - use a short antenna for the rx, point your beam away, adjust rx RF - gain). Monitor the error histogram for a few minutes, until you have - say 5000 total bit errors. You have a problem if the BER of any - carrier is more than 20% different from the rest. - - A typical issue will be one carrier at 1.0, the others at 0.5, - indicating the poorer carrier BER is twice the larger. +TODO: Put this in a more usable form (maybe parse into HTML), video +tutorials etc... + +1/ Error Histogram +------------------ + +Displays BER of each carrier when in "test frame" +mode. As each QPSK carrier has 2 bits there are 2*Nc histogram +points. + +Ideally all carriers will have about the same BER (+/- 20% after 5000 +total bit errors). However problems can occur with filtering in the +tx path. If one carrier has less power, then it will have a higher +BER. The errors in this carrier will tend to dominate overall +BER. For example if one carrier is attenuated due to SSB filter ripple +in the tx path then the BER on that carrier will be higher. This is +bad news for DV. + +Suggested usage: + +i) Transmit FreeDV in test frame mode. Use a 2nd rx (or +get a friend) to monitor your rx signal with FreeDV in test frame +mode. + +ii) Adjust your rx SNR to get a BER of a few % (e.g. reduce tx +power, use a short antenna for the rx, point your beam away, adjust rx +RF gain). + +iii) Monitor the error histogram for a few minutes, until you +have say 5000 total bit errors. You have a problem if the BER of any +carrier is more than 20% different from the rest. + +A typical issue will be one carrier at 1.0, the others at 0.5, +indicating the poorer carrier BER is twice the larger. + +2/ Voice Keyer +-------------- + +Puts FreeDV and your radio into transmit, reads a wave +file of your voice to call CQ, then switches to receive to see if +anyone is replying. If you press space bar the voice keyer stops. If +a signal with a valid sync is received for a few seconds the voice +keyer stops. The Tools-PTT dialog can be used to select the wave +file, set the Rx delay, and number of times the tx/rx cycle repeats. + +3/ UDP Control port +------------------- + +FreeDV can be controlled via UDP from other programs on the same host +(127.0.0.1) using text strings. The default port is 3000, and can be +set Via Tools-Options. + +Currents commands: + + "set txtmsg XXX" - sets the text/callsign ID string to XXX + "restore" - Restores the FreeDV windowto full size if minimised + "ptton" - PTT on (transmit) + "pttoff" - PTT off (receive) + +Hint: "netcat" can be used to test this feature. -- 2.25.1