Low Pass filter, SWR and TXRX switch

I have completed the PCB for the LowPass FIlter, SWR and TXRX switching for the Concept SDR system. The SWR part is based on the design and kit from Kits and Parts. Note that it uses FT37-43 cores which have a much higher Al than the T37-6 of the LPF, the inductance of the 10t windings is 44uH to make the broadband transformers. Have a look at the kit also to see how they are mounted and wired.

This is the schematic:

And here is the board, the PA input is top right. The links on the board at the left allow you to connect directly to the G0 output of the VFO (for example for direct WSPR transmissions) or the TX shield output (TX shield yet to be made...):



This is the stack of Arduino Uno, VFO & RTC, SDR RX and the new LPF & SWR & TXRX switch shields:

This is the LPF_SWR_40M shield mounted on a VFO_RTC_IQ shield to form a WSPR beacon:



Note the wire link bottom left to connect the VFO G0 output to the LPF input.