DIY antenna ?

[ampulman]

I'm thinking about putting together a copper cactus antenna for attic installation.

SCANNER ANTENNA

Would I achieve a gain factor if the elements were 5/8 wave instead of 1/4?

Do 5/8 wave antennas require a ground plane?

Amp

 

[LtDoc]

That 1/4 wave version would be much simpler to build. Any 5/8 wave antenna will require an impedance matching device, they are not 50 ohms (or close). Receivers aren't as 'picky' about impedance as transmitters are, but they still 'like' 50 ohms if they can get it. So, if you want to go to the trouble I think you could realize some gain. And then, being inside rather than outside, I also figure that gain will be marginal, sort of.
Do both! that way you'll have something to do comparisons with.
- 'Doc

 

[ampulman]

That 1/4 wave version would be much simpler to build. Any 5/8 wave antenna will require an impedance matching device, they are not 50 ohms (or close). Receivers aren't as 'picky' about impedance as transmitters are, but they still 'like' 50 ohms if they can get it. So, if you want to go to the trouble I think you could realize some gain. And then, being inside rather than outside, I also figure that gain will be marginal, sort of.
Do both! that way you'll have something to do comparisons with.
- 'Doc

This will be for receive only, for scanners. Currently, besides my duckies, I'm using an indoor offset centered dipole with RG6 coax located in my second floor 'radio room'.

My reason for the installation is mostly to be able to improve reception of an 800 Mhz trunked system designed to stay within city limits (Philly).

Amp