question - MultiCOM Antenna
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question - MultiCOM Antenna
by kev » Sat Sep 02, 2017 9:10 pm
hi just been and bought a MultiCOM Wide Band Multi-Scan Base Scanner Antenna 25- 1300mhz, how far will this antenna pick up (distance) as I have it on the roof, thanks in advance.
- kev
- Posts: 3
- Joined: Tue Aug 22, 2017 6:09 pm
Re: question
by G4RMT » Sat Sep 02, 2017 9:48 pm
Well - I tried to download the pdf spec and it's empty of information - however, the picture suggests a few things. Inside I'm pretty sure what it contains is a number of lengths of wire, cut to length to be resonant at the centre of popular bands - so to cover 25MHz, there's no way it can be a quarter wave long, so the performance at that frequency range will be pretty poor. Once you get up to the VHF air band it will start to do the job. Above 470MHz, the performance will drop off again. So you have something with low visibility that isn't as visually annoying as say a discone. At frequencies in between the popular bands, performance drops off, but that probably doesn't matter too much.
If you are listening to aircraft - then at 30,000ft, you will hear them many hundreds of miles away. However - if you live 20 miles from the airport it lands at, you might lose it at 1000ft. You might hear taxis at 5 miles, but hear their base 15 miles away. You might not hear the local motorcycle school unless they are within half a mile.
The only real info is to suggest you look at a topographical map of your area, or use some of the software you can get on the internet. With the aerial up high, clear of obstructions and your house on the top of a hill, the range you get can be impressive, but if you live in the bottom of a valley, or have your house blocking the antenna - then tens of miles turn into half a mile very quickly.
Radio is often described as line of sight - if you had some mega binoculars and could actually see the thing you wish to hear, it will work. A walkie talkie in the space station can work the whole of europe on a Watt or two. In a city, pushing more than a few hundred metres can be impossible.
You're probably going to have to wait and see - we cannot give specific answers, sorry.
If you are listening to aircraft - then at 30,000ft, you will hear them many hundreds of miles away. However - if you live 20 miles from the airport it lands at, you might lose it at 1000ft. You might hear taxis at 5 miles, but hear their base 15 miles away. You might not hear the local motorcycle school unless they are within half a mile.
The only real info is to suggest you look at a topographical map of your area, or use some of the software you can get on the internet. With the aerial up high, clear of obstructions and your house on the top of a hill, the range you get can be impressive, but if you live in the bottom of a valley, or have your house blocking the antenna - then tens of miles turn into half a mile very quickly.
Radio is often described as line of sight - if you had some mega binoculars and could actually see the thing you wish to hear, it will work. A walkie talkie in the space station can work the whole of europe on a Watt or two. In a city, pushing more than a few hundred metres can be impossible.
You're probably going to have to wait and see - we cannot give specific answers, sorry.
- G4RMT
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- Joined: Sat Feb 07, 2015 5:45 pm
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