[Elecraft] Powering a K3s from a battery?

[Edward R Cole]

Wes,

So you are saying all of us with K3/10 should never run at 10w+ 
because the LPA is a terrible producer of IMD?  Does that also apply 
to the KX3 which is also a 10-12w radio (160-24m)?

I'm finding that hard to swallow considering the QRP background of 
the Elecraft owners.

I note the topic started about using a battery but you cite this is 
still true at 14v regulated supply.

Or are you saying this only about running the HPA at 10w? (which I do 
not have).  I thought the HPA switched off below a set power level 
(again, not something I need to know since I do not have a HPA).

Wayne you want to respond on this?

I'd like to think I did blow a whole lot a money on a defective 
design (I bought both the K3/10 and KX3).

Oh HNY!
73, Ed - KL7UW
considering the KXPA100 a after Christmas purchase


Date: Wed, 30 Dec 2015 09:19:41 -0700
From: "Wes (N7WS)" <wes at triconet.org>
To: elecraft at mailman.qth.net
Subject: Re: [Elecraft] Powering a K3s from a battery?
Message-ID: <5684041D.5080207 at triconet.org>
Content-Type: text/plain; charset=utf-8; format=flowed

I'm not missing a thing.

All I'm saying is that if you run the LPA at 10-12 watts, according to my
measurements*, the IMD is pretty bad.  If you have an HPA, then after it's
kicked in, (13W in my K3S) the LPA is running at greatly reduced 
power.  I don't
believe Elecraft has to change anything.  Guys with a KPA3(A) just 
need to avoid
the grey area of 10-15W.

Wes  N7WS

*Remarkably, IMD measurements I made on my K3S using modest equipment 
correlated
within 1dB or less to measurements made by Elecraft, on the same radio.

   On 12/30/2015 12:08 AM, Jim Brown wrote:
 > Something you're missing, Wes. The 100W amp doesn't kick in until 
you ask for
 > more than about 14W. So at 11-12W, you're seeing the IMD of the QRP exciter
 > stage running near it's maximum power.
 >
 > I'm wondering if it might be practical to modify the control 
software so that
 > the 100W amp kicks in at lower power levels. Are there other consequences?
 > Wayne?
 >
 > 73, Jim K9YC
 >
 > On Tue,12/29/2015 8:19 PM, Wes (N7WS) wrote:
 >> Something else to note, even at 14V, running a K3 at 11-12 watts 
is a disaster.
 >



73, Ed - KL7UW
http://www.kl7uw.com
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