On Tue, May 27, 2025 at 02:37 PM, paul wrote:
maybe use the filter switch lines as voltages for USB/LSB?
I considered that. I can't imagine buying the filters at current prices. I had a CW filter on my FT101ZD MkIII I passed on to a friend recently.
I hadn't thought of the shortcut. I usually have A=IPO and B=Att, or else A=Power set.
I'm thinking I can add 1 more transistor (or likely a small VFET) and make the transistor switch used to add capacitance for USB into 1/2 of a SR Latch. Then make the mic Up & Down set USB and LSB. The VFET would drive an LED at the speaker grill holes (as it's offset) to indicate LSB mode. The power on default can be USB (likely but can be ensured by small capacitor on gate.
I've also tried all forms of the "Reset", but nothing from the Car-DDS. I have a decent Rigol SA, 20 MHz Hameg and 100 MHz (2 Gs/s) digital scope. Using a scope probe on the Rigol SA at 10:1 as it's 50 / 75 Ohms.
A more exotic solution would be monitor user selection of Mode via CAT and then setting the oscillator shift. It's certainly stable enough for SSB. I don't do FT8 anyway :D
Mike EI9FEB