[Elecraft] K2 Power Control Question

Clark Macaulay clark.macaulay at gmail.com
Mon Dec 17 21:46:58 EST 2018


Ahhhh......

Thanks.  Forgot about the interaction of the ATU bridge and the Power
Control setting.

Measured R of MFJ unit = 57 Ohms.  Yuk.  Replaced it with my NORCAL load
which measured 49.5 ohms.  Now the LP100A shows SWR = 1.02.  Will
re-balance the bridge and report back.

BTW:  don't you ever sleep?

On Mon, Dec 17, 2018 at 9:27 PM Don Wilhelm <donwilh at embarqmail.com> wrote:

> Clark,
>
> The "secret" is to properly balance and calibrate the KAT2 wattmeter.
>
> If you do the balance with a dummy load that is truly a 50 ohm resistive
> load ( a 1.13 SWR just does not "cut it"), then adjust the forward KAT2
> pot to give you the same K2 display as indicated by the LP-100, your
> power should track nicely.
>
> Your K2 power output does depend on the correct calibration of the KAT2
> wattmeter.
>
> 73,
> Don W3FPR
>
> On 12/17/2018 9:03 PM, engineercm wrote:
> > I'm becoming more active in QRP contesting and need to make sure that my
> > power is <5W.  I thought I was aligned ok until I put my LP100A into the
> > shack (what a wonderful instrument).  When Power Control = 5.0, the
> LP100A =
> > 3.0.  Now, I want to be below 5.0, but not that low!  To reach LP100A =
> 5,
> > Power Control must be set at 7.5 (40m) and 8.5 (20m).  This is with the
> ATU
> > = Cal(P), which removes the matching circuits.  The dummy load is a
> MFJ-264;
> > the LP100A SWR = 1.13.
> >
>


-- 
72,

Clark, WU4B
QRPARCI #10815
SKCC #3892
NAQCC #5055
CWOPS #1869
Collins Collectors #AC90-12432
Southeastern DX Club <http://www.sedxc.org>
North Georgia QRP Club <http://www.nogaqrp.org>


*"It is vain to do with more what can be done with less."*
*Attributed to *William of Occam (1288 AD - 1348 AD)


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