diff --git a/doc/user_guide/en/controls-functions-center.adoc b/doc/user_guide/en/controls-functions-center.adoc index 5f7a36d06..decfe09bd 100644 --- a/doc/user_guide/en/controls-functions-center.adoc +++ b/doc/user_guide/en/controls-functions-center.adoc @@ -37,11 +37,13 @@ TIP: Consider reducing power if your QSO partner reports your signal above -5 dB in one of the _WSJT-X_ slow modes. These are supposed to be weak signal modes! -* With *Rx frequency offset with "CQ nnn"* checked on the *Settings -> -General* tab and *Split operation* activated on the *Settings -> -Radio* tab, you can activate the spinner control *CQ Rx nnn* by -checking the box to its right. The program will then generate -something like `CQ 285 K1ABC FN42` for your CQ message, and it will -handle the appropriate frequency switching between a CQ on the -conventional calling frequency and completing your QSO on the -specified offset frequency. \ No newline at end of file +* With *Split operation* activated on the *Settings -> Radio* tab, you +can activate the spinner control *Tx CQ nnn* by checking the box to +its right. The program will then generate something like `CQ nnn +K1ABC FN42` for your CQ message, where `nnn` is the kHz portion of +your current operating frequency. Your CQ message *Tx6* will then be +transmitted at the calling frequency selected in the *Tx CQ nnn* spinner +control. All other messages will be transmitted at your current +operating frequency. On reception, when you double-click on a message +like `CQ nnn K1ABC FN42` your rig will QSY to the specified frequency +so you can call the station at his specified response frequency. diff --git a/doc/user_guide/en/images/decode-menu.png b/doc/user_guide/en/images/decode-menu.png index 32d618648..7fa1a430f 100644 Binary files a/doc/user_guide/en/images/decode-menu.png and b/doc/user_guide/en/images/decode-menu.png differ diff --git a/doc/user_guide/en/images/misc-controls-center.png b/doc/user_guide/en/images/misc-controls-center.png index 55d675a1c..4778e03ea 100644 Binary files a/doc/user_guide/en/images/misc-controls-center.png and b/doc/user_guide/en/images/misc-controls-center.png differ diff --git a/doc/user_guide/en/odds_and_ends.adoc b/doc/user_guide/en/odds_and_ends.adoc index 6dc9447c6..c7a1e40a3 100644 --- a/doc/user_guide/en/odds_and_ends.adoc +++ b/doc/user_guide/en/odds_and_ends.adoc @@ -32,7 +32,7 @@ End of line information:: `f` - Franke-Taylor or Fano algorithm + `M` - Message length (characters) + `N` - Number of Rx intervals or frames averaged + - `R` - Amount of _a priori_ information used by decoder + + `R` - Return code from QRA64 decoder + `T` - Length of analyzed region (s) === Reference Spectrum diff --git a/doc/user_guide/en/protocols.adoc b/doc/user_guide/en/protocols.adoc index eac7c7932..410d30009 100644 --- a/doc/user_guide/en/protocols.adoc +++ b/doc/user_guide/en/protocols.adoc @@ -126,12 +126,11 @@ separation is 110250/4096 = 26.92 Hz multiplied by n for JT65A, with n QRA64 is an experimental mode intended for EME and other extreme weak-signal applications. Its internal code was designed by IV3NWV. -The protocol uses a (63,12) Q-ary Repeat Accumulate code that is -inherently better than the Reed Solomon (63,12) code used in JT65, -yielding a 1.3 dB advantage. A new synchronizing scheme is based on -three 7 x 7 Costas arrays. This change yields another 1.9 dB -advantage. A few details of the QRA64 protocol are still subject to -change, as more experience is gained. +The protocol uses a (63,12) **Q**-ary **R**epeat **A**ccumulate code +that is inherently better than the Reed Solomon (63,12) code used in +JT65, yielding a 1.3 dB advantage. A new synchronizing scheme is based +on three 7 x 7 Costas arrays. This change yields another 1.9 dB +advantage. In most respects the current implementation of QRA64 is operationally similar to JT65. QRA64 does not use two-tone shorthand messages, and @@ -141,8 +140,7 @@ QSO progresses -- for example, when reports are being exchanged and you have already decoded both callsigns in a previous transmission. QRA64 presently offers no message averaging capability, though that feature may be added. In early tests, many EME QSOs were made using -submodes QRA64A-E on bands from 144 MHz to 10 GHz. Optimum processing -of signals with large Doppler spread remains to be implemented. +submodes QRA64A-E on bands from 144 MHz to 24 GHz. [[SLOW_SUMMARY]] ==== Summary diff --git a/doc/user_guide/en/vhf-features.adoc b/doc/user_guide/en/vhf-features.adoc index 7c097f6ed..754f0462b 100644 --- a/doc/user_guide/en/vhf-features.adoc +++ b/doc/user_guide/en/vhf-features.adoc @@ -159,13 +159,28 @@ _WSJT-X_. The mode is designed especially for EME on VHF and higher bands; operation is generally similar to JT65. The following screen shot shows an example of a QRA64C transmission from DL7YC recorded at G3WDG over the EME path at 24 GHz. Doppler spread on the path was 78 -Hz, so although the signal is reasonable strong its tones are -broadened enough to make them hardto see on the waterfall. The red +Hz, so although the signal is reasonably strong its tones are +broadened enough to make them hard to see on the waterfall. The red curve shows that the decoder has achieved synchronization with a -signal at about 970 Hz. +signal at approximately 967 Hz. image::QRA64.png[align="center",alt="QRA64"] +The QRA64 decoder makes no use of a callsign database. Instead, it +takes advantage of _a priori_ (already known) information such as the +one's own callsign and the encoded form of message word `CQ`. In +normal usage, as a QSO progresses the available _a priori_ (AP) +information increases to include the callsign of the station being +worked and perhaps also his/her 4-digit grid locator. The decoder +always begins by attempting to decode the full message using no AP +information. If this attempt fails, additional attempts are made +using available AP information to provide initial hypotheses about the +message content. At the end of each iteration the decoder computes +the extrinsic probability of the most likely value for each of the +message's 12 six-bit information symbols. A decode is declared only +when the total probability for all 12 symbols has converged to an +unambiguous value very close to 1. + === ISCAT ISCAT is a useful mode for signals that are weak but more or less