uBITX AM BCI Filter (3.5mhz High Pass Filter)
My PCB : https://easyeda.com/nikpolini/uBITX_3_5mMHZ_HPF-56119a38a46d434fa6d5e9f27e7bdba9
I am still developing/testing this board size and placement
Use T30-6 :
- 1.622uF = 21 turns (0.4mm wire, 31cm length)
- 1.461uF = 20 turns (0.4mm wire, 29cm length)
Use 1206 SMD NPO capacitors.
9mm x 33mm
You need to cut the second trace from the PA side. They are in order:
1: TX pwr to the PA circuits via R89
2: RX path (between K1 and K3 relays. (CUT AND INSERT HERE)
3: TX pwr to the LPF bank.
4: RX pwr to the receive circuit (R18,R38...)
I picked up GND from the 2 unused caps C216 and C210