Good Morning All,
There have been a number of good comments concerning the v5.0 schematic. Those comments along with my own concerns about certain things in the posted schematic have motivated me to make the following changes:
1) The present use of two of the switches in the FST3126 (U4) for a receiver mute function will change to use those two switches in parallel with the the two QSD switches to lower the signal path switch resistance. The receiver mute function will need to be done in the software. (Not a good reason, but I need to stay with the FST3126 part because I have over 1000 pieces left from a minimum order buy for v4.0 kits. Anyone need any FST3126 parts? :-) )
2) The BPF ground will connect to the antenna ground only but two vias will be provided to jumper the antenna ground to the circuit ground.
3) L21 and L22 as well as T21 will be wound on toroid cores so a kit builder may more easily adjust the BPF design and transformer turns ratio. ( I am thinking about providing a set of cores in the kit to span the HF amateur bands.)
The board layout is coming along pretty well and I will be making the above changes in the next few days. I will post a new schematic this evening, but will continue to be open to additional suggestions.
Thanks and 73,
Tony KB9YIG
