I just installed an A-99 on my camper. It has a push up pole, but I don't have a tool to raise it at the moment. I tested it out at roof level, and the vswr was acceptable so I transmitted voice. I was blown away by the very loud and crystal clear talkback on my stereo. At 5 watts ssb I don't hear anything. 7 watts makes a little noise, and 40 is loud as heck through the old stereo. Will raising it 10 to 20 feet above the roof make a huge difference? Are modern electronics less prone to interference than my 70's pioneer?