[Elecraft] Power Measurements with question

[S55M]

Hello Fran!

I think You are far too much perfectionist...:)
The difference between 15.2W and 16.8W in db is +41.81dBm to +42.25dBm that
is 0.44dB.
One S unit is 6dB so You can figure out  the difference.The difference for
me is meaningless and as You see from Your table it makes sense that on
lower QRG You get more power. Sometimes is difficult to make power sensors
perfectly linear and then converting RF to DC for regulation. I didn't
looked on K2 schematic to explore the fact but i can say that everithing
works perfect....


Good DX's
S55M-Adi

----- Original Message ----- 
From: "Francis Belliveau" <f.belliveau at comcast.net>
To: "Elecraft-List" <elecraft at mailman.qth.net>
Sent: Sunday, March 13, 2005 10:54 PM
Subject: [Elecraft] Power Measurements with question


> I have completed my attempts to measure the power output from my K2 using
an
> o'scope.  I must say that my attempts were not successful.  For some
reason
> when set to 10 watts I get about twice the voltage as when set for 5
watts.
> At 15.2 I get about 3 times.  This does not make sense because of the V*V
> term would indicate 9 times the 5 watt output when set for 15 watts.  I
know
> that this cannot be true!
>
> Now I do have a KAT2 installed and as I understand it this should improve
> the accuracy of the power output because of the more accurate power
> measurement.  I set the K2 to display output power and got the following
> results:
>
>     MHz  Req=5.0  Req=10.0  Req=15.2
>      3.6        6.4         12.6          16.1
>      7.1        6.2         10.7          15.6
>     10.1       5.5         11.5          15.5
>     14.1       5.6         11.0          16.6
>     18.1       5.2         11.1          14.8
>     21.1       5.7         10.8          14.1
>     24.9       5.7         11.0          14.4
>     28.1       5.7         11.0          14.1
>
>
> It certainly makes sense that when requesting 15.2 watts I get only 14
watts
> at higher frequencies, but why would I ever get readings that are
> significantly above the requested output power?
> I thought that this reading is what tells the controller how much power to
> output.
>
> This is certainly a puzzle to me.
>
> Fran
>
>
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