Been busy modding the QRP Labs QCX transceiver and like to share it, so someone might get some inspirtation from it.
As i already have a KX3 with paddle, i 3d printed a bracket to mount the KXPD3 paddle to the QCX, for this had to move the headphones jack (yes i am lefthanded)
I joint 4 Li-ion cells to a 4S battery with nominal voltage of 14.8 Volt (cell type 103040, 30x40x10mm, 1200mAh, 3.7V) it fits inside the housing underneath the PCB. i put a thin sheet of insulating foam between battery and PCB keeping the batterypack firmly in place.
At the GPS connector location a made a 6Pin connector with one pin blocked so i can’t put the charging connecter in wrong, now i can balance charge the individual li-ion cells.
I replaced the power connector with a 3.5mm stereo audiojack for the headphones.
I mounted a P-channel FET witch switches the power supply on/off by plugging in/out the headphones.
The transceiver is now standalone and with 1 meter coax and a end-fed antenna using a FT82-43 transformer with 10 meter wire i now have a 5Watt 20mtr portable CW station weighing under 600 grams. As for battery life, it seems oke, but needs further testing.
some more foto’s at: https://www.daverveld.eu/