Improve Swr Metal Roof

To alleviate this keep at least the top 12 inches of the antenna above the roof line and position the antenna as high as possible on the vehicle.

Improve swr metal roof. Not an expert but the metal roof should block the signal. The antenna then converts this rf energy into electro magnetic energy which is radiated into space. Often the critical frequency for nvis is below 40m like 5 mhz and down. When we got a lot of snow recently the swr went to 8 10 or higher.

What s directly beneath the horizontal antenna may impact nvis which is pretty much a 10 mhz and below propagation method and the metal roof might actually improve that if you work 30 40 60 80 meters but probably not notably. The feed line is lmr400. What type of secondary water resistant barrier is my wind mitigation report referring to. Swr cost appears to vary widely based on articles i have read and a quick web search but i would expect probably in the range of 0 10 0 15 sf of total roof for only the joint sealing product 1 20 1 40 sf extra for the full coverage sheet installed product done as part of a normal reroof job.

I have a gp 6 2 meter 440 vertical mounted on a metal pipe that is attached to one end of a metal roof. Also try the indoor antenna by the windows. Swr or standing wave ratio is a measurement of antenna efficiency. The sheet product itself runs about 1 00 sf.

While the swr measures 1 1 1 5 at the antenna it has always been higher at the radio. A 36 width roof underlayment install with ring shank nails having a minimum 20 rings per inch a minimum head diameter of 3 8 thru 1 5 8 tin caps or ring shank metal cap nails having a 1 diameter and long enough to penetrate the deck per code. Cireofmi jun 14 2009. This serves as a barrier to prevent the water from entering the home even after the primary barrier the roof covering system such as shingles or.

For the purpose of the wind mitigation inspection form 1802 a secondary water resistant barrier is a self adhering modified bitumen underlayment. Basically this is a peel and stick type of material that is installed before the shingles. In the event of a catastrophic storm that damages the roof of the home one of the ways people can prevent water intrusion is to have what is called a secondary water resistant swr barrier. When you transmit you are sending radio frequency energy along your feedline usually coax to your antenna.

If your antenna is mounted down low on the vehicle like on the bumper or behind a pickup truck s cab the signal can bounce back to the antenna causing a high swr.