noob question- i have already started building first antenna

[ballisticmike]

hello all, nice forum here. oh boy, where do i start.. i am so un-knowledgable but i will keep my question concise. I searched and search and searched on google, very little concise, specific info that i could find on my application. Now even though it looks to me like most of the discussions on your forums are non-car radio based i will ask anyway because i bet alot of you know the answers nonetheless.

In a nutshell- i want to replace the OEM antenna thats on my 2008 F150 with a custom made one.. something much shinier, cooler. and IF POSSIBLE.. will perform close to the same level as the OEM one. I know theres already tons of aftermarket ones on ebay.. billet shorty antenna mostly made with aluminum etc. I dont want and dont like those. I will be making one much much nicer than those.. more artistic, show quality. From stainless steel.

One of the only bits of info i found on google says that 31" is the most common and best compromise for an automotive AM/FM antenna. I measured my Ford antenna, sure enough its 31". Some other bit i read started talking about ratios and 1/4 wave and thats why 31" is best and on and on with technical jargon i dont understand.

So heres my question: my Ford OEM 31" antenna weighs 58.5 grams on my digital scale. I want my custom antenna to be shorter.. probably 15.5". Is it ideal that i maintain the same weight.. 58.5 grams? Is this the way the formula works? In other words my custom antenna with be a larger gauge wire and even though its shorter I can make it keep the same weight as the original , thats not a problem for me to do.

Sidenote: i removed my original antenna and stuck my prototype shorty antenna in, then put the AM tuner on a really weak station and compared reception to OEM antenna. Result.. mine not quite as good but hardly different. Am i way off base in my assumptions here?

 

[ballisticmike]

i should clarify something cause after reading my own post it may not be clear. The purpose of this custom antenna is simply to operate the AM/FM stereo in my truck. And look nicer than the origional stock antenna. Thats it. I will also mention my truck has factory Sirius sat radio and a dedicated reciever for that on the roof.
The other point to be mentioned.. i've read product reveiws of people who buy shorty billet antanae for thier cars.. most of them say its not quite as clear as factory but looks nicer so they are happy with that. Usually these antenna are about 12 or 14 inches. If u live in the city then reception is less an issue. If u live way out in the sticks reception becomes an issue. I simply want to have smart info in building a show quality antenna thats shorter and at same time will work decently. TIA

 

[ballisticmike]

aww c'mon guys, someone must have an idea about this stuff

 

[n4yek]

So heres my question: my Ford OEM 31" antenna weighs 58.5 grams on my digital scale. I want my custom antenna to be shorter.. probably 15.5". Is it ideal that i maintain the same weight.. 58.5 grams? Is this the way the formula works?

No, one full wave-length antenna for fm broadcast would be 124" at 90.0 MHz on your FM radio.
One quarter ( 1/4 ) wavelength is 31.2" (124" / 4 = 31.2") Thats how the formula works, it isn't by weight.

In other words my custom antenna with be a larger gauge wire and even though its shorter I can make it keep the same weight as the original , thats not a problem for me to do.

A larger gauge wire will give you more bandwidth, so if you shorten your antenna that would be something you would want to do.

Sidenote: i removed my original antenna and stuck my prototype shorty antenna in, then put the AM tuner on a really weak station and compared reception to OEM antenna. Result.. mine not quite as good but hardly different. Am i way off base in my assumptions here?

As for AM stations, you won't affect them too much. An antenna for that band at a quarter wavelength would be about 135 Feet tall