On Nov 22, 2020, at 10:47, Tom Crites <crites57@...> wrote:

I guess my question is with a FlexRadio Systems FLEX-6300 should I just leave the Split Operation set to None and just set my transmit frequency to a clear area with Shift-Left Click?

Tom,

If 'Fake it' is working use it. The User Guide in 4.2. Radio recommends:
Either method will result in a cleaner transmitted signal, by keeping the Tx audio always in the range 1500 to 2000 Hz so that audio harmonics cannot pass through the Tx sideband filter.

Without split mode you need to be very careful not to overdrive any transmission path audio related element for whatever reason, when operating below 1000 Hz audio frequency.

73, Reino OH3mA

Hi Tom, Mark, and Reino,

with an all digital Tx audio chain not using one of the WSJT-X split modes may be OK but I would agree with Reino. There is no need for a Tx bandwidth far greater than the bandwidth of the transmitted signal. WSJT-X will manage the tone frequencies and VFO frequency such that a narrow Tx bandwidth is no problem. You could even use a pass band of 1500 Hz to 2000 Hz, although that is unnecessarily narrow. Using a normal SSB Tx bandwidth and WSJT-X split operating ensures any audio harmonics, however the might be generated, to be greatly attenuated. Given the more complex VFO arrangement on the Flex Signature Series rigs "Settings->Radio->Split Operating->Fake It" would seem the best option.

73
Bill
G4WJS.