Thanks God, I have a second radio in the shack with a second antenna on the rooftop! It is the good old WiNRADiO G-303e. I run it at a magnetic loop antenna, a "Baby Loop" of Ciro I3VHF in Verona. The loop comes with a convenient automatic tuner unit, just type in the frequency and the tuner does the rest. So I have DSP, roofing filters, a preselector in the form of the magnetic loop antenna, variable IF filters, "AGC off", simply everything. The G-303e is a wonderful piece of engineering.
But. There is a problem when transmitting with the FT-757GX. The G-303e won't be damaged, no. I have a relay in the feeder to the magnetic loop and the FT-757 triggers that relay upon transmitting. But the sensitive front-end of the G-303e picks up so much energy that the audio is overloaded. The DSP goes mad, The AGC needs time to recover from the overload. One cannot just use it together with the transmitter. The G303e was obviously never built for such an environment. Other professional radios like the old Sailor series have a muting input terminal which can be connected with the transmitter so that the receiver is muted when necessary. Not so the G-303e.
The G-303e indeed has a "mute" button and it works. However, it must be activated with the mouse, there is no keyboard shortcut. This is the difficult part during a QSO. In the heat of the battle, every ten transmissions I forget to mute the radio and the G-303e audio goes mad. The external computer speaker is overloaded. I was already thinking of using a keyboard with an audio mute button that is easier to use than the "mouse/mute" button. The audio mute button then mutes the external speaker so that at least I would prevent the whole family from being waken up by my radio.
There is another problem with the G-303e software. Cw signals which are shown in the IF spectrum window in white color cannot be seen under the yellowish window which indicates the IF filter bandwidth. There should be a better combinations of colors.
The best for the time being would be a piece of hardware at the computer which acts together with the WiNRADiO software when the hardware is triggered by the FT-757GX.
As I start to think, there may be a solution. WiNRADiO provides "Radio Basic", a programming language for the G-303e. Maybe this is the way. One can influence the receiver volume, attenuator, ÍF gain, perfect, everything there. But appearently no means for inputting anything else than keyboard information. But I could assign the space key to a toggle operation which reads out the actual values, stores them, and mutes the radio by setting them to zero. The next toggle activation would restore the old values. This works but I often forget to mute before transmitting.