I got my inspiration from BCC and SJ2W sites.

PI4CC use exclusive the K3 tranceivers. All of them have the 2nd receiver build-in.
When using the a 2nd antenna to receive via the 2nd receiver, you can listen in different directions. So you can hear e.g. on 15 meters in your left ear UA and in your right ear W,K stations. Also multi pad propagation can be dectected. Listen to 3B9EME in CW with 1 one beam short path and 1 to South America. 3B9EME is walking form one ear to the other on a quit band. An other example is 4U1GSC. He is running a ssb contest to USA when a LU7 showed up at the same qrg. When K and LU are transmitting on the same time you can hear them both very well.

If you can also transmit on both antennas, you will create more attention on the band. This is the idea behind the layout. In 2012 I build the first prototype. This prototype needed some modification, but in the base, its working well. In 2013 I did go back to the drawing table and make a new layout. A gallery of the 2nd prototype design can be seen here.

		De powersplitter is stackmatch, with a extra RX port added.
		The controller can select ANT1 or ANT2 of both. TX and RX independent