I used to love heavy legal limit iron and still do. I like regional ssb rag
chewing on 160 & 80. Like many I have a full size low dipole for this work and
can attest that the difference between 600, 1000, and 1500 watts is little if
any. I used to run 1500 watts regularly but sold that capability. Now I run
600 or 1000 watts because my back can handle moving those amps (Acom 600S &
AL-80A) and none of the regulars I communicate with have complained about my
non legal limit signal.
If 600 or 1000 watts doesn't cut it, perhaps 1500 may make a difference but
having to listen to very noisy band conditions like that for long periods tends
to drive me to the recliner and remote control.
I kind of miss seeing the PEP watt meter easily swing to 1500 though!
73, k0cwo
> On Dec 8, 2016, at 8:28 AM, Jim Thomson <jim.thom@telus.net> wrote:
>
> Date: Thu, 08 Dec 2016 12:48:20 +0800
> From: Alek Petkovic <vk6apk@bigpond.com>
> To: AMPS <amps@contesting.com>
> Subject: Re: [Amps] 600W vs 1.5KW amps was: Re: SS amps and
> autotune...
>
> I know very little to nothing about the fineries of solid state amps but
> I do know, that it's the first half kilowatt, whichever way its derived,
> that does all the work and makes all the difference on the S meter.
>
> 73, Alek
> VK6APK
>
> ## The old timers back in the day all said the same thing. The 1st 500 watts
> does all the
> work, the rest just heats up the shack.
>
> 100-200 = 3db
> 100-300 = 4.77
> 100-400 = 6.0
> 100-500 = 6.99
> 100-600 = 7.78
> 100-700 = 8.45
> 100-800 = 9.03
> 100-900 = 9.54
> 100-1000 = 10.0
> 100-1100 = 10.41
> 100-1200 = 10.79
> 100-1300 = 11.14
> 100-1400 = 11.46
> 100-1500 = 11.76
> 100-2000 = 13.01
> 100-2500 = 13.98
> 100-5000 = 16.99
> 100-10000 = 20.00
>
> As you can see, a point of diminishing returns occurs. But dbs are
> accumulative too.
> Going from 600w to 1200w buys you a lousy 3db. But start doing stuff like
> using a bigger
> yagi, putting the bigger yagi up higher, or even putting the existing
> smaller yagi up higher,
> using lower loss coax, etc, then the additional 3db from the bigger
> amp..combined with the
> better yagi / coax setup can easily yield a net 6++ db improvement.... at
> least on TX. A .5 db here,
> and 1db there, and a couple more db from something else...all soon adds up.
>
> Tiny incremental increases by themselves may not seem like its worth it, but
> do a bunch of small
> incremental increases, and it adds up...fast. Of course the bigger amp
> doesnt buy you anything on RX,
> but it will if BOTH stations at each end of the circuit use a bigger amp.
>
> You cant work em if you cant hear em. Well you cant work em....if they cant
> hear you.
> You have to get practical too. Most folks on postage size city lots are
> lucky if they can muster up
> an inverted vee at 50 ft on 80m. 2 x similarly equipped stations may well
> have a hard time talking
> to each other on a noisy summer time 75m band...with each running a 100w
> Xcvr. Simple fix is add at
> least a 500w amp...another 7 db..at both stations. Lower bands with their
> inherent ant limitations +
> more noise on RX greatly benefit from more TX power.
>
> For mobile applications, a 500w SS amp is almost mandatory....esp on the
> lower bands.
>
> Jim VE7RF
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