[Elecraft] K3S QST Article

[Wes Stewart]

My experience suggests that running the low power amp in a K3(S) above 10W is a 
disaster. In a K3(S)/100 the HPA isn't activated until above 12W.  IMHO, again 
based only on my measurements of my K3 and my K3S (before mods), I would 
recommend that Elecraft change firmware to set the max power out at 10W (LP) and 
switch in the KPA100 above 10W, not 12.

On 10/14/2016 9:17 PM, Edward R Cole wrote:
> OK.  I purchased the K3/10 in 2010 which is able to output up to 12w.
>
> Is the low power amp any better at IMD, or subject to the same limitations 
> because its 12v transistors?
> I bought the KXPA-100 last year.  Would it be any better than the KPA3 or 
> KPA3A?  3rd-order IMD in the vicinity of -30 dBc is about what I have read for 
> specs my many 12v power devices.
>
> I bought the new synth because I understood it would improve Rx performance 
> (haven't installed them yet main & sub Rx).  Also for K3 use at 630m.
>
> Would running the K3/10 at 5w driving a linear amp be lower in IMD?  The amp 
> uses 50v devices and made for TV which has greater linearity specs than SSB. I 
> am also running it at about 60% full output on 6m.
>
> 73, Ed - KL7UW
> http://www.kl7uw.com
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