AntennaX...help!
05-17-2012, 07:16 PM
#1
JK Enthusiast
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AntennaX...help!
So I just replaced my stock fm antenna with a 14" billet AntennaX antenna. I'm not sold yet... I can only pick up about 1/3 of the stations I was able to get before BUT then again, the stations I do get are crystal clear. Is this a common thing with stubby/aftermarket/antennaX antenna???
I'm not forgetting something stupid am I? I know tuning an FM antenna isn't an issue but is there anything else that may help?
I'm not forgetting something stupid am I? I know tuning an FM antenna isn't an issue but is there anything else that may help?
05-18-2012, 01:16 AM
#4
JK Junkie
Here is the long technical answer....
You can calculate the length of any 1/4 wave antenna by dividing 234 by the frequency desired in mHz. This gives you the approx. length in feet. To get it in inches, simply multiply by 12.
So for FM broadcast, which has a range of 88-108 mHz, you could calculate for mid band (unless you have a special station you listen to all the time). This would be 98 mHz. so....
234/98 = 2.388 ft X 12" = 28.7"
If you go to the bottom of the band, 88 mHz it becomes 234/88 = 2.66' X 12" = 31.9"
Just for the fun of it, I measured the factory antennas on three cars and they ranged from 29" to 32", essentially what we calculated above. I'd probably go for the 32" length, since receive antennas aren't as length critical as transmit antennas. Hope this helps
You can calculate the length of any 1/4 wave antenna by dividing 234 by the frequency desired in mHz. This gives you the approx. length in feet. To get it in inches, simply multiply by 12.
So for FM broadcast, which has a range of 88-108 mHz, you could calculate for mid band (unless you have a special station you listen to all the time). This would be 98 mHz. so....
234/98 = 2.388 ft X 12" = 28.7"
If you go to the bottom of the band, 88 mHz it becomes 234/88 = 2.66' X 12" = 31.9"
Just for the fun of it, I measured the factory antennas on three cars and they ranged from 29" to 32", essentially what we calculated above. I'd probably go for the 32" length, since receive antennas aren't as length critical as transmit antennas. Hope this helps
05-18-2012, 01:43 AM
#5
JK Freak
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^^^^
Your not going to ask me to find the value of x are you?
I have heard this before my question is I dont even have an antenna, was gone when I bought the Jeep. So wouldn't the case be with me my stations and reception would get way better?
Your not going to ask me to find the value of x are you?
I have heard this before my question is I dont even have an antenna, was gone when I bought the Jeep. So wouldn't the case be with me my stations and reception would get way better?
05-18-2012, 01:59 AM
#6
JK Junkie
No it is too early in the morning for solving math problems.
OK so here is the short layman answer....
No antenna ==> 13" stubby would be an improvement!!
Taking a 30" antenna and cutting down to 13" or 14" ==> looks "cool" but your going to suffer with reduced FM performance especially if you live/drive away from large cities or FM transmitters.
OK so here is the short layman answer....
No antenna ==> 13" stubby would be an improvement!!
Taking a 30" antenna and cutting down to 13" or 14" ==> looks "cool" but your going to suffer with reduced FM performance especially if you live/drive away from large cities or FM transmitters.
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05-19-2012, 04:46 AM
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05-19-2012, 05:10 AM
#10
JK Super Freak
I'll try to sum up the technical stuff in non-technical terms. Antennas for radio have a relationship between the physical size of the antenna and the frequencies they are intended to receive (or transmit) effectively. For FM radio, the stock antenna on most vehicles is a decent size match to the FM broadcast radio frequencies. When you select an antenna shorter than the factory antenna, you are reducing antenna efficiency, sometimes significantly.
There are valid reasons someone may run a less efficient antenna, like tree limb clearance or aesthetics, but it's important to understand the efficiency is compromised.
This is the same reason that, all other things constant, a guy with a 102" whip antenna for his CB will have performance that dominates a guy with a 24" Firestick antenna.
There are valid reasons someone may run a less efficient antenna, like tree limb clearance or aesthetics, but it's important to understand the efficiency is compromised.
This is the same reason that, all other things constant, a guy with a 102" whip antenna for his CB will have performance that dominates a guy with a 24" Firestick antenna.
