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Sirio 5000pl length

357magnum said:
DeedleD , Like your avatar # 1 , # 2 It's nice to see Sirio got back to you so fast ! Good Deal , Some places Don't or take weeks !
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Thanks 357magnum, I've been an amrron member for years, thought it would be appropriate to ident as such... Regarding Sirio, agreed, some don't even bother responding, others take forever but Sirio seems to be on top of it! Quality product and customer service no doubt!
 
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Hmm. Every time you halve an antenna length because radiation resistance works as a function of the square you decrease the performance by 6dB or 75% so a 39" one is going to transmit and receive a signal probably somewhere around 30% of the strength of a full height one. There are ways around that to increase the efficiency but that is done at the expense of bandwidth so you'd have fewer channels you'd get below 2:1 SWR.
 
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M0GVZ said:
Hmm. Every time you halve an antenna length because radiation resistance works as a function of the square you decrease the performance by 6dB or 75% so a 39" one is going to transmit and receive a signal probably somewhere around 30% of the strength of a full height one. There are ways around that to increase the efficiency but that is done at the expense of bandwidth so you'd have fewer channels you'd get below 2:1 SWR.
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This definitely seems to be the case. I compared my 3’ Midland antenna with my 5’ Wilson 1000 last night, and Wilson was able to hit the base with 10 pounds vs Midland at 9 pounds from 8 miles away. Furthermore, the SWR remained flat with the taller antenna across the band vs 1.2 midband and 1.5 at the edges with the smaller antenna. With that said, to each their own, but I personally can live with1 s-unit decrease vs a 5-foot tall antenna on the roof of the vehicle hitting everything in sight.
 

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