Antenna..

[darthtony]

Hi i have a cheap receiver wich covers the airband, and uses a telescoping antenna.
I want to make a better antenna in order to hear more.
Any ideas?I am a complete newbie, and i want it to be as simple and cheap as possible
Most designs i have seen use a coaxial cable and i also wonder were should i connect the two cables to my receiver.(one on the antenna, and the other on the '-' of the battery?

[Dave_B]

You might want to mention what you have, because that might make this easier to answer.

Off the cuff, I would say the right way to do it is go to Radio Shack and buy a female chassis-mount BNC connector and drill a hole in the back of the radio and mount the connector, and take a small piece of coaxial cable and solder the center conductor to wherever that old telescoping antenna attaches and the shield of that cable to ground on the main board, and then the other end of the center conductor to the center tab on the BNC and the other end of the shield to the outer ring of the BNC.

I only suggest BNC instead of SO-239 because it takes up a LOT less room on your receiver. But for all I know, you don't even have room for a BNC.

Then you will be able to attach any number of antennas to the thing.

However, if you can afford to upgrade, I would do that instead. You can sell that radio to someone who doesn't care as much about performance and get one that doesn't need this little modification, which might not be appreciated by the next guy.

[darthtony]

First of all thanks for your answer.
The radio i have is the cheapest i could find on ebay (around 15 euros) and my budget is very small so i will go with the mod:P)So i connect the center to the antenna and the outer to the ground on the pcb. ok then what antenna should i make?

[Dave_B]

Doing that mod will allow you to do pretty much anything with antennas because you can connect whatever you want. An outdoor antenna would obviously be best, and what you do there is dependent on how much trouble you want to go through. The simplest and cheapest would be a small ground plane antenna, which you could make out out of a chassis-mount SO-239 connector if you wanted to really go bare-bones. Just get one of those and find some copper or brass rod (or even steel - whatever you find) and solder into the center conductor (on the "back" not on the threaded side). Then you can use the four mounting holes to hold four radials of the same material. The material just needs to be stiff enough to hold up because the vertical element needs to be about 23" long. The radials should be that long too but you can cheat on those if you have to. Then figure out a way to mount that little contraption somewhere, connect a cable between the two (if a short run, RG-8X or even RG-58 will be okay), and you will be cooking.

Of course you can buy any number of high performance antennas (just Google 'scanner antenna') but my solution will be the best bang for the buck. because it will cost less than 5 bucks to make and will work well on the aviation band.