i got a discone antenna. bout 8 years old (when i joineded maybe) on roof on a 100 ft line i guess. just scanning locally in newark nj about 2 miles from airport straight line. wanted to get more DISTANCE on receiving. should i RAISE antenna? its about 8 ft on highest point on 45 ft roof. house on left,right and rear are taller then antenna. bc355n i use. i did own a uniden digital...on antenna which reached i-95 along FAR side of airport. MAYBE IM FINE but is higher better? mines antenna has i THINK center whip 20 inches maybe or better and those 4-5 going around it on bottom. txs all in advance....nice scanning again.
Others have answered you really well. Here's what I'll add.
Most of the frequencies that your scanner will receive work by line of sight. If your antenna can "see" the transmitting antenna, it'll work. There are some slight variations to this, but it gives you a general idea. Raising the antenna up higher will increase what the antenna can "see".
However, raising it 3 feet probably isn't going to make a big difference. It won't hurt, and if you can safely do it, go for it, but don't expect that to solve your issues.
All coaxial cable has loss. As frequencies go up, losses go up. As cable gets longer, losses go up. Lower grade coaxial cable has more loss than higher grade cables. Without knowing what type of coaxial cable you are using, it's hard to say, but you may want to consider a higher grade cable.
Also, if you have a bunch of unused cable coiled up, that is not doing you any favors. The right amount of coaxial cable you need is exactly the amount to get from your antenna to your radio. No more, no less.
Other issue we often see on the hobby side is that people rarely waterproof the outdoor connections. If your coaxial cable connection to your antenna was not properly waterproofed at installation, then expect that some water intrusion happened. That water will get into the connectors and potentially into the coaxial cable itself and start corroding the copper.
If I was in your shoes, here's what I'd do….
Sure, raise the antenna that extra 3 feet, it's not going to hurt.
Disassemble everything and inspect. Make sure the antenna is in good shape, no rust, corrosion, etc.
Replace the coaxial cable. Get enough to reach from your antenna to your radio, with a few feet of slack. The type of cable you need depends on your budget, the actual length needed, and which frequencies you need to listen to.
-On the antenna end, get the connector that matches what is on the antenna base. Use no adapters.
-Properly waterproof the connection. Use coaxial cable sealing tape. Electrical tape/duct tape/chewing gum is not sufficient.
-Properly secure the cable to make sure there is no stress on the connector.
-On the radio end, terminate the cable with a female N connector. Use a short length of flexible cable with a male N connector on one end and a connector on the other end to match your radio. This short 'whip' of flexible cable will take the strain off your scanners antenna connection.
If installing coaxial connectors is not your strong point, there's nothing wrong with buying coaxial cable with pre-installed connectors.
