[Elecraft] KX1 Output Power

[KW4H]

John,

You're going to really enjoy building and using the KX1.  I've been "hooked"
on the KX1 for a few years, and it's my favorite rig.  I don't go hiking,
camping, or mountaintop operating -- but the KX1 is fantastic for sitting
out on the deck, throwing a line into the trees (or putting up the
Buddipole), and making a few QSOs.  The KX1 is my "ham radio in a bag" when
we go to the beach or take a trip somewhere.  Also, building it is pure joy.

73,

Steve, KW4H

On Sat, Dec 4, 2010 at 11:08 PM, John Overbaugh <john.overbaugh at gmail.com>wrote:

> Wow--I received a plethora of responses, all pretty much saying what Don's
> said here - external 13.8 power supply will yield just about 4 watts.
> Internal batteries, which are only going to run around 9v (6 x 1.5 = 9)
> will
> only crank out around 2 watts.
>
> Many thanks for the help. I'm dutifully saving up for my first Elecraft,
> which will be the KX1. I'm hoping to have a nice project for the holidays!
>
> 73's,
>
> John O.
> K7JTO
>
> On Sat, Dec 4, 2010 at 4:27 PM, Don Wilhelm <w3fpr at embarqmail.com> wrote:
>
> >  John,
> >
> > The power output of the KX1 is dependent on the power supply voltage.
> > A well constructed KX1 will normally deliver 4 watts on 80, 40 and 30
> > meters, and 3.5 watts on 20 meters with a 13.8 volt power source.  Some
> will
> > do a little better and some a bit worse than that target figure.
> >
> > The voltage produced by the 6 internal cells is less than 13.8, and the
> > exact voltage depends on the battery type.  Lithium batteries normally
> are
> > the best if the power level is important to you, with alkalines running
> in
> > second place.  NiCad or NiMH batteries will produce lower voltages and
> > therefore lower power.  To get to that 13.8 volt level, each of the 6 AA
> > cells would have to produce 2.3 volts.
> >
> > But yes, as a general rule, 2 watts is to be expected when using the
> > internal batteries.  There is just not enough room to pack additional
> > batteries inside.
> >
> > A few KX1 owners have modified the KX1 to use rechargable Lithium Ion
> > batteries which produce a higher voltage (and more power as a result).
> >
> > I want to offer a caution - running the the KX1 at greater than 4 watts
> can
> > cause damage to the components following the PA amplifier - with a good
> 50
> > ohm pure resistive load, one can go a bit higher without harm, but as the
> > SWR increases, the voltages in the low pass filter will also increase and
> > could exceed their voltage ratings.
> > In other words, don't try to push the KX1 power too high - the difference
> > between 3.5 watts and 5 watts is almost imperceptible on the receiving
> end.
> >
> > 73,
> > Don W3FPR
> >
> >
> > On 12/4/2010 4:20 PM, John Overbaugh wrote:
> >
> >> In researching the KX1, I thought I had read that it's possible to get 4
> >> watts of output. However, the manual shows 2 watts as the max from
> >> internal
> >> batteries. Is 4 watts possible? Does it require external batteries?
> >>
> >>
>
>
> --
> John Overbaugh
> blog: http://kf7dvj.blogspot.com
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