diff --git a/doc/user_guide/en/vhf-features.adoc b/doc/user_guide/en/vhf-features.adoc index 365641108..88328def8 100644 --- a/doc/user_guide/en/vhf-features.adoc +++ b/doc/user_guide/en/vhf-features.adoc @@ -52,6 +52,9 @@ computed for the middle of the Tx period. *Fake It*; you may need to experiment with both options to find one that works best with your radio). +- Select *Tab 1* to present the traditional format for selecting Tx +messages. + The main window will reconfigure itself as necessary to display controls supporting the features of each mode. @@ -106,9 +109,9 @@ is generally used for EME on the 5.7 and 10 GHz bands. of a single tone. To activate automatic generation of these messages, check the box labeled *Sh*. -- Select *Deep* from the *Decode* menu. You may also choose to enable -averaging over successive transmissions and/or correlation decoding, -also known as "`Deep Search`". +- Select *Deep* from the *Decode* menu. You may also choose to *Enable +averaging* over successive transmissions and/or correlation decoding, +*Enable deep Search*. image::decoding_depth.png[align="center",alt="Decoding Depth"] @@ -118,67 +121,71 @@ EME path have been compiled by G3WDG and are available here: {jt4eme}. === JT65 In most ways JT65 operation on VHF and higher bands is similar to HF -usage, but a few differences should be noted. Checking the box -*Enable VHF/UHF/Microwave features* on the *Settings -> General* tab -causes several additional user controls to be displayed. The decoder -will respond to special message formats used particularly for EME, -including the OOO signal report and shorthand messages for RO, RRR, -and 73. Typical operation at VHF and UHF involves only a single -signal in the receiver passband, rather than many. It's usually best -then to check the *Single decode* box on the *Settings -> General* -tab. +usage. However, a few differences should be noted. Typical VHF/UHF +operation involves only a single signal in the receiver passband, or +perhaps a few, rather than many. Normally it's best to check *Single +decode* on the *Settings -> General* tab and uncheck *Two pass +decoding* on the *Advanced* tab. In this mode the JT65 decoder will +respond to special message formats sometimes used for EME, including +the OOO signal report and shorthand messages for RO, RRR, and 73. +Those messages will be automatically generated if you check the +shorthand message box *Sh*. + +As for JT4, you should check *Deep* on *the *Decode* menu, and +optionally *Enable averaging* and *Deep search*. + === QRA64 -QRA64 is present as an experimental mode in the present alpha release -of _WSJT-X_, Version 1.7. Operation is basically similar to JT65. +QRA64 is an experimental mode in the present alpha release of +_WSJT-X_, Version 1.7. The protocol is still subject to change, and +some features of the decoder will likely change. In most ways +operation of QRA64 is similar to JT65. === Meteor Scatter with MSK144 Meteor-scatter QSOs can be made at any time on the VHF bands, at distances up to about 2100 km or 1300 miles. Completing a QSO takes longer in the evening than in the morning, longer at 144 MHz than at -50 MHz, and longer at 2000 km than 1500 km; but with patience, at +50 MHz, and longer at 2000 km than 1500 km. But with patience, at least 100 Watts, and a single yagi it can usually be done. -- Select *Tab 1* to present the traditional format for selecting Tx -messages. - - Select *MSK144* from the *Mode* and *Fast* from the *Decode* menu. - Set the audio receiving frequency to *Rx 1500 Hz*, frequency tolerance to *F Tol 100*, and T/R sequence duration to 15 s. -- MSK144 does decodes received signals in real time, so you can see +- MSK144 decodes received signals in real time, so you will see decoded messages almost as soon as you hear them. To match decoding -depth to your computer's capability, click *Monitor* (if -necessary) to start a receiving sequence, and observe the percentage -of CPU usage displayed on the _Receiving_ label in the Status Bar: +depth to your computer's capability, click *Monitor* (if it's not +already green) to start a receiving sequence and observe the +percentage of CPU usage displayed on the _Receiving_ label in the +Status Bar: image::Rx_pct_MSK144.png[align="center",alt="MSK144 Percent CPU"] -- This number (here 17%) measures the fraction of CPU capability used -being used by the MSK144 real-time decoder. If it is well below, say, -80% you may increase the decoding depth from *Fast* to *Normal* or -*Deep*, and increase *F Tol* from 100 to 200 Hz. +- The displayed number (here 17%) indicates the fraction of CPU +capability used being used by the MSK144 real-time decoder. If it is +well below 100% you may increase the decoding depth from *Fast* +to *Normal* or *Deep*, and increase *F Tol* from 100 to 200 Hz. -IMPORTANT: Most modern multi-core computers can easily handle these -maximum parameters, but some slower machines may not be able to keep -up. In that case there will be some loss in decoding capability for -the weakest pings. - -- You may now proceed to make QSOs using essentially the same -procedures described in <>. +IMPORTANT: Most modern multi-core computers can easily handle the +optimum parameters *Deep* and *F Tol 200*. Slower machines may not be +able to keep up at these settings; in that case there will be a modest +loss in decoding capability for the weakest pings. - T/R sequences of 15 seconds or less make it sometimes desirable to -switch transmitted messages very quickly. Check the *Auto Seq* box -to have the computer make the necessary decisions automatically. +advance your selection of transmitted messages very quickly. Check +*Auto Seq* to have the computer make the necessary decisions +automatically, based on received messages. -- For operation at 144 MHz or above, you might choose to use the -MSK144 short-format messages for Tx3, Tx4, and Tx5. Check the box -labeled *Sh* to enable this feature. (There is little need for this -option at 50 or 70 MHz, where most pings are long enough to support -the standard MSK144 message length.) +- For operation at 144 MHz or above it is advantageous to use the +short-format messages for Tx3, Tx4, and Tx5. Check the box labeled +*Sh* to enable this feature. + +IMPORTANT: There is little need to use MSK144 *Sh* messages at 50 or +70 MHz, where most pings are long enough to support the standard +MSK144 message length. === Scatter Propagation with ISCAT @@ -187,7 +194,7 @@ TBD ... === Echo Mode *Echo* mode allows you to make sensitive measurements of your own -lunar echoes, even when they are too weak to be heard. Select *Echo* +lunar echoes even when they are too weak to be heard. Select *Echo* from the *Mode* menu, aim your antenna at the moon, pick a clear frequency, and toggle click *Tx Enable*. _WSJT-X_ will then cycle through the following loop every 6 seconds: @@ -202,14 +209,11 @@ To make a sequence of echo tests: - Select *Echo* from the *Mode* menu. -- On the Astronomical Data window check *Doppler tracking* and -*Constant frequency on the Moon* +- Check *Doppler tracking* and *Constant frequency on the Moon* on the +Astronomical Data window. -- Choose your desired test frequency using the *Frequency above nominal -band edge* controls. - -- Be sure that your rig control has been set up for _Split Operation_ -(either *Rig* or *Fake It*) on the *Settings | Radio* tab. +- Be sure that your rig control has been set up for _Split Operation_, +using either *Rig* or *Fake It* on the *Settings | Radio* tab. - Click *Enable Tx* on the main window to start a sequence of 6-second cycles.