DIY Antenna Mounting Bracket
From The RadioReference Wiki
This is a very easy project to add more antennas on masts etc. Get yourself some 1/4" thick aluminum about 8"X8" from your local metal supplier or similar hardware stores, those screws are not needed!.
You will also need four 2 1/4" muffler clamps.
You can buy smaller if you prefer but I would rather go a little bigger on the clamps so you can fit up to a 2" metal or aluminum mast if you chose.
More info to come
Take care Tonsoffun