Frequency used to tune 5/8 whip antenna

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gaguilar

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Confused on which frequency to use when cutting a 5/8 whip antenna. Main reason of purchasing antenna was to hear TxDPS. Frequency range is mostly from 154.6800-159.2175. Do I cut using the frequency 154 MHZ (cut 44 3/4) ?
 
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prcguy

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It can matter a lot and an extreme example I've seen is a 5/8 cut for the 2m amateur band at 146MHz was way down on reception at 162MHz weather freqs by almost 20dB. A 5/8 is very sharply tuned and even the 5MHz spread from 154 to 159MHz will degrade some.

I would cut the antenna for somewhere in the middle of your frequency range like 157MHz.
 

gaguilar

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It can matter a lot and an extreme example I've seen is a 5/8 cut for the 2m amateur band at 146MHz was way down on reception at 162MHz weather freqs by almost 20dB. A 5/8 is very sharply tuned and even the 5MHz spread from 154 to 159MHz will degrade some.

I would cut the antenna for somewhere in the middle of your frequency range like 157MHz.
Thank you, cut it down 155MHz (did not want to cut to low in case needed to adjust) to see what it does. Noticed i was able to catch law enforcement 50+ miles. Going to trim down little more. I live in Corpus Christi, Tx and was able to catch Jim Wells, Duval and Kenedy Counties. Was able to catch Harlingen and Freer DPS Dispatch once.
 

n3obl

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Thank you, cut it down 155MHz (did not want to cut to low in case needed to adjust) to see what it does. Noticed i was able to catch law enforcement 50+ miles. Going to trim down little more. I live in Corpus Christi, Tx and was able to catch Jim Wells, Duval and Kenedy Counties. Was able to catch Harlingen and Freer DPS Dispatch once.
I would not trim any more.
 
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