[Elecraft] KX1 power output question :-(

Tue Apr 20 00:34:00 2004

I still come up short.  The increased supply voltage made a difference, but not
much.

With a supply V of 13.7V
showing 13.6V on TX in 40m
and showing 13.5V on TX in 20m
typical readings I get at the power tap on the dummy load are:

(( V * 1.414 ) + 0.15 )^2 / 49.5 => P  <-- taken from the DL1 instructions
(my DL1 tests at 49.5ohms, hence the divisor is not 50)

7.4VDC => 2.28W
7.5VDC => 2.34W

(I would have to see 8.5VDC to result in even 3W, and I have never seen
anything close to this.  And forget about the 9.84VDC I would need to result in
4W.)

I trust these readings more, but they correspond with the little RS power meter
I have.

I guess I am just dishartened at this point, because everything up to this
point has tested fine, I tested all the things I was told to in the manual, as
well as anything else I could think of, and it's just not quite 3-4W.  I guess
at this point I am wondering if I should be calling Elecraft support.

Any help is always appreciated.

dt
.

--- Ron D'Eau Claire <[email protected]> wrote:
> The output power is very dependent upon the supply voltage. It drops off
> fast as you go down from 13.8 vdc. I don't have my notes here so I can't
> tell you if your value looks typical, but if you can put a 13.8 v supply on
> it you should see at least 3 watts. 
> 
> Ron AC7AC
> 
> -----Original Message-----
> I am in the final stages of testing and allignment of my KX1
> 
> With R4 fully clockwise
> I plugged in an Elecraft Dummy Load and a DMM on the power tap I plugged in
> a 4 Ahr battery I selected TUNE The loaded voltage of the battery is approx
> 12.45V The draw is 350mA from the battery The dummy load tap only indicates
> (after calculation) 2.24W on 20m and 2.02W on 40m But the manual says I
> should get 3-4W
> ...The only suspicions I have at this point are:
> 1) the battery is not running a full charge (13.8V), so I put it on charge
> before I left for work and will try again when I get home
> 2) maybe I am not getting a good voltage reading at the voltage tap on the
> dummy load, so I bought a BNC-UHF adapter to see what my RS watt meter says
> tonight
> 
> Does anyone else have any ideas/suspicions/suggestions?
> 
> dt
> 
> 
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