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Re: [TowerTalk] Measuring Coax Loss

To: "Tower and HF antenna construction topics." <>
Subject: Re: [TowerTalk] Measuring Coax Loss
From: jimlux <>
Reply-to: "Tower and HF antenna construction topics." <>
Date: Fri, 12 Feb 2010 09:29:53 -0800
List-post: <">>
Tony Brock-Fisher wrote:
> All this talk about gong to extremes for lowest loss is perhaps
> mis-directed...
> To me, it boils down to db/$. Where can you put your (available)
> funds to best use in your shack? Certainly if coax loss is your
> lowest cost opportunity for improvement, you should go for it.
> (Recall the coax loss applies in both directions, tx and rx).
> On the other hand, if you can improve station performance by more dbs
> for the same cost somewhere else, such as better antennas, etc, then
> go for that before going for super-low-loss coax.

And in ham radio, it's kind of interesting, because if you're a serious 
contester, you can hit regulatory limits in one area of system 
optimization: PA output power.  After that, you have to start 
contemplating getting dBs from antennas or coax.

However, that does make the early trade easy..
If buying an amplifier to go from 500 to 1000 watts costs $3000, then 
you're paying $1000/dB.  I'd find it hard to believe that for a moderate 
length run of coax (say <300-500 ft) that even paying full retail 
whether you couldn't beat that, except that there's probably only a dB 
or 2 to pick up (unless your existing coax is RG-174 or something)

  OK.. but once you've hit the 1500W limit, there's no point in spending 
more money on the amp (unless you're going to go the "active antenna 
tuner" approach<grin>) at least from a link budget standpoint (I could 
easily see paying more for a better amplifier, even at the same power.. 
more robust, faster tuning, less electricity cost)


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