No balun is needed with this antenna. The mast is 30' tall. Inside the PVC (3") is an Advanced Receiver UHF preamp and PAR 225-400 Mhz band pass filter. The PVC is protecting those devices from water damage. I'm waiting on the proper fittings...got it going with what I had. I'll be able to make the housing shorter when they arrive. With this setup I can hear for example all the ground side transmissions of a ARTCC RCAG 35 miles away, all with a S-8 reading.