Will AM/FM antenna works with VHF radio?

[sekstant1]

Today I rush to West Marine store, I grab first antenna on rack. When I got home- I find- I got AM/FM 5120 Shakespeare antenna. May I use it for VHF (cobra) radio. I guest NOT. Thanks for any advise.

 

[Don S]

Re: Will AM/FM antenna works with VHF radio?

Nope..... Different insides.

 

[MH Hawker]

Re: Will AM/FM antenna works with VHF radio?

NO the if you try to tramsmit it will fry the VHF.

 

[jhebert]

Re: Will AM/FM antenna works with VHF radio?

Today I rush to West Marine store, I grab first antenna on rack. When I got home- I find- I got AM/FM 5120 Shakespeare antenna. May I use it for VHF (cobra) radio. I guest NOT. Thanks for any advise.

An antenna tuned for the AM Broadcast band is designed to work at a frequency of 0.55-MHz.
An antenna tuned for the VHF Marine band is designed to work at a frequency of 157-MHz.

The two frequencies are different by a ratio of 157/0.55 = 285:1.
You should expect an antenna to have a useful bandwidth for frequencies that are a ratio of 1:1.05.
The ratio of the AM Broadcast Band to the VHF Marine Band exceeds the reasonable expectation of bandwidth by a factor of 270:1.

I am afraid your expectation of the antenna working is an exaggeration of the reality by a factor of 270-to-1. So, in short, no, it will not work well.

 

[FastFission]

Re: Will AM/FM antenna works with VHF radio?

Just a quick explanation. For a two-way radio, the antennas are designed to transmit over a pretty narrow range of frequencies. In a nutshell, if you have the antenna tuned just right, most of the power from your radio will get transmitted out into the world. If the antenna is not properly tuned, some of that power gets reflected back into the transmitter. If you're far enough off, enough power gets reflected back to burn out the transmitter.

Short answer - get the right antenna.