Il 27/10/18 21:58, Bill Somerville ha scritto: > On 28/10/2018 01:30, Morris Wideman via wsjt-devel wrote: >> My MP does not put out full power but if you have a way to increase >> the TX audio level such as mic gain then this is not that big a problem. > > Morris, > > this is a very bad idea. Increasing the audio drive to compensate for > the SSB IF filter attenuating the Tx signal will almost certainly > overload the modulator input. This is particularly poor practice if > you do this to compensate for a low frequency audio tone as the > resulting audio harmonics will pass through the SSB IF filter > unattenuated leaving you with a filthy Tx signal. > > The correct way to deal with Tx audio frequencies outside of the Tx > SSB IF filter passband is to either restrict your operation to Tx > audio offsets to above 1500 Hz (to keep any audio harmonics outside of > the passband) and to below ~2400 Hz, alternatively if you have CAT > control you should enable "Settings->Radio->Split Operating" and let > WSJT-X do the right thing automatically; then there are no > restrictions on the Tx audio offset you may use. > > Incidentally, this is one of the reasons that using the rig's ALC > indication to estimate the correct audio drive is missing the point > and may result in poor Tx signals. > > 73 > Bill > G4WJS. > > > > _______________________________________________ > wsjt-devel mailing list > wsjt-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/wsjt-devel Hi Bill,
I have some doubts here regarding the WSJT-X TX audio settings, because my radio is a very modest and not so modern YAESU FT-100 and I verified that it can't handle frequencies above about 2900 Hz or below about a couple of hundred Hertz, probably due its SSB filters passband. When I try to set frequencies out of the standard my RF power went strongly reduced. Despite this limitation, from the *FT8_DXpedition_Mode* instructions we can read that we could set Tx audio carrier up to 4.000Hz: /Select Tab 1 on the main window for transmitted messages, and set Tx nnnn Hz to// //a Tx frequency *between 1000 and 4000 Hz*. You can also select a Tx frequency by// //using Shift+Click on the waterfall display. You may find frequencies above 3000// //Hz are desitable because they have less QRM. Select the “Tx1” message under// //Next./ Hence I would like to know: is the above Tx audio setting always possible? How do we can set this higher frequency on older transceivers like mine, which has not "too much adjustments" to play with? Thanks for your kind attention! Best regards, -- 73 de Marco, PY1ZRJ
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