Antenna help please!

[Jlwhitt77]

I have a couple questions about some homebrew antenna set ups.

Lets start with a scanner set up. I've got an old radio shack scanner that the telescopic built in antenna busted on. it has a jack on the back for a portable type antenna. I have removed that jack and installed a female pl-259. My plan is to make a dipole antenna that I can mount on my rooftop. I live 10 miles from the nearest town that I would like to monitor and 40 miles from the other area I would like to monitor. the frequencies I would like to receive are in the155. and 458. range. Is it possible to build two separate antennas tuned for those frequencies, run those two antennas backwards into a splitter then from the splitter into my scanner? Also will these antennas need a choke on them? Is there a simpler way of achieving my goal?

Second question; I am also planning on a center fed dipole t2lt homebrew set up made of coax for a base station. I've got an old cobra 29 that's been tuned. It dead keys at 3 and peeks at about 7. With a properly tuned antenna how well should I expect to be able to transmit?

I'm new to all of this and after researching the web I am finding out there is a lot of wery confusin information about radio. lol

 

[w9cll]

Is it possible to build two separate antennas tuned for those frequencies, run those two antennas backwards into a splitter then from the splitter into my scanner?

One Discone will cover those nicely.

Second question; I am also planning on a center fed dipole t2lt homebrew set up made of coax for a base station.

Vertical or horizontal?

 

[Jlwhitt77]

One Discone will cover those nicely.

Discone, Please inform me. I have never heard of this. On the base antenna it will be vertical unless it is advised otherwise.

 

[w9cll]

A Discone is an excellent receiving antenna (will Xmit on some fregs). Do a quick Google search and you will find a lot

 

[w9cll]

On the base antenna it will be vertical unless it is advised otherwise.

For local CB talking you want vertical

 

[RatsoW8]

A female PL-259 is called an SO-239. Diploes for vhf/uhf frequencies would be very small and wouldn't work very well mounted horizontally. Follow w9cll's advise and pick up a discone or other outdoor scanner antenna. I think Radio Shack still sells one.

 

[Jlwhitt77]

A female PL-259 is called an SO-239. Diploes for vhf/uhf frequencies would be very small and wouldn't work very well mounted horizontally. Follow w9cll's advise and pick up a discone or other outdoor scanner antenna. I think Radio Shack still sells one.

this is the home brew section, right? looking now how to home brew a discone fore desired frequencies. thanks for educating on SO-239

 

[Road Squawker]

I would consider BUILDING a copper pipe J-Pole

 

[Jlwhitt77]

I would consider BUILDING a copper pipe J-Pole

ok sounds easier than a discone. Where can I find instructions for the build?

 

[Jlwhitt77]

http://www.n7qvc.com/copper-cactus-dual-band-super-j-pole-antenna-project/

 

[vkrules]

http://vk2zoi.com/articles/dual-band-half-wave-flower-pot/ There you go, a dual band T2lt style homebrew ant
Original design is for 144 -148 and 432 -450 mhz ,should work fine for the scanner frequencies you want.

Actually a T2lt cut for 150 mhz would be all you would need. the uhf frequency is almost 3 times the vhf frequency and will work.

 

[Jlwhitt77]

http://www.n7qvc.com/copper-cactus-dual-band-super-j-pole-antenna-project/ wow.this is amazingly simple. Do you think built for the 440 mhz range would recieve 150 mhz in same fashion as vise versa? The antenna would be a third of the size.

 

[Jlwhitt77]

Actually a T2lt cut for 150 mhz would be all you would need. the uhf frequency is almost 3 times the vhf frequency and will work.

thisis what i meant to copy in last post.

 

[Jlwhitt77]

Actually a T2lt cut for 150 mhz would be all you would need. the uhf frequency is almost 3 times the vhf frequency and will work.

yes and adjust the choke to 5 turns rather than 9? Or does that even matter for receive? This is all new to me.

 

[vkrules]

leave it 9 turns http://vk2zoi.com/articles/half-wave-flower-pot/
And no ,make the 144mhz version not the 450 mhz for best receive .