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Frequency and Whip!?

Sam Quentin · 2018-05-13 18:07:55

Are those online whip length to radio frequency calculators accurate and is frequency between 66-88 called Medium Wave or Low Band?? I'm taking about car aerial/whip and not base. And also if I use a mag mount do I measure from magnet base(roof of car)or just measure the actual whip/antenna??

13-05-2018 07:07PM

#1

Sam Quentin

Registered Users, Registered Users 2 Posts: 2,236 ✭✭✭

Join Date: August 2013

Posts: 2091

Are those online whip length to radio frequency calculators accurate and is frequency between 66-88 called Medium Wave or Low Band??
I'm taking about car aerial/whip and not base. And also if I use a mag mount do I measure from magnet base(roof of car)or just measure the actual whip/antenna??

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Comments

#2 29-05-2018 11:13AM

humaxf1

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Posts: 728

Simply divide 300 by the frequency in MHz which gives a full wave-length. Mobile whip lengths are usually 1/4 wave, so divide your answer by 4.

Take the fire-service for example who operate on 84MHz (we'll use 84.4375 as an example)

300/84.4375= 3.55 meters. 3.55/4= 0.888m or 88.8cm.

For transmitting, round it up to maybe 95cm and trim the length for SWR. Measure from the point where the whip leaves the stud.

66-88MHz is known as low-band VHF

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