Added op-amp buffer to receiver, increased capacitor values
Simplified over-voltage protection on analog inputs
Modified RX switch to prevent turn-on during transmission
Changed RX impedance to 50 ohms
Added more buttons and encoders
Fixed part designation on op-amps. Replaced tl072 with lm4562 for simpler BOM.
Added LED indicators on MCU
Added RTC crystal, moved DIT and DAH to port B.
Added thermistor to measure PA temperature
Changed low-pass in PA to 5th-order elliptic
Reduced capacitance of C406 due to mosfet drain capacitance
Since we have a lot more features that require connections between
the amplifier, synthesizer, and microcontroller, I'm trying out the
bus routing in the schematic to make it easier to add wires between
the three modules.
- Fixed connector alignment between power amplifier board and main board
- Selected filter values for the 40m band
- Grounded the enable pin of the analog mux
Buck regulator changed from AP6320 to JW5057 due to availability in Chinese markets
Encoder footprint updated according to datasheet. Should be loose enough for most encoders to fit.