Locked Re: Radio tabs set to Fake it or None
On 28/12/2020 02:56, Jacques Pecourt wrote:
both "Split Operating" "Rig" and "Fake It" have the same purpose which is to optimize your transmitted signal in two important ways. The first is to allow you to transmit at any audio offset without regard for the bandwidth and shaping of your transmitter's Tx SSB filters. The second is to ensure that you signal is clean and clear of any audio harmonics that might have been generated by over-driving the transmitter modulator, which is easily done and hard to detect without a second monitoring system or expensive test gear. It does that by ensuring all harmonics are placed above the low-pass cut-off frequency of a typical transmitter SSB filters.
"Rig" is always preferred if it works reliably, particularly if you are using any sort of VOX or other external keying including audio interfaces that generate a hardwired PTT signal from observing the presence of Tx audio (the SignaLink USB interface being an example). The reason the "Rig" setting is preferred is that there is no ambiguity between the timing of the rig switching to SEND and the adjustment of frequency necessary to do what this option requires. "Rig" uses SPLIT on the rig which implicitly synchronizes the transitions to SEND and back to RECEIVE and the necessary frequency changes. OTOH "Fake It" relies on the sequencing of commands sent to the rig, which is OK if they all use the same channel, i.e. CAT control of frequency and PTT, but are potentially ambiguous if VOX or hardwired PTT driven by a serial port RTS or DTR signal (possibly with an external sequencer including deliberate delays to protect pre-amplifiers and relays) is involved.
In summary, if you are using any mode that requires varying Tx audio offsets, or Doppler correction for EME operating, then "Settings->Radio->Split Operating->Rig" is always preferred. "Fake It" is an acceptable alternative if you have a dual receiver rig and wish to use the second receiver for other purposes, or if CAT control of SPLIT does not work correctly. "None" should be considered a lowest common denominator default to be avoided unless it is really the only one that works.