[Elecraft] KX1 still Low Power

Phil Wheeler [email protected]
Fri Nov 28 22:36:03 2003


Ron and Alan,

I just changed R30 from 22 to 36 ohms.  Now power is 4.4 W on 40 (a bit 
high) and 3.2 W on 20 (OK).  The difference is larger than I would like  
.. though I'm not sure it matters (the caution in manual related to more 
power on 20 than on 40 and that's not where I'm at)  And I've not been 
able to change that noticably so far by re-spacing the turns on L2, 
though maybe I need to do that more aggressively.  Reducing the 40 m 
output to 3.6 W (using R4) takes 20 W below 3 W, so there is no joy there.

I think I will set R4 to get 4 W on 40 m and see where that puts me on 
20.  Then I will get more aggressive on L2 turn compression.

73, Phil

Ron D'Eau Claire wrote:

>Phil... look at the 40 meter transmit test on Page 59 of the Rev B manual.
>Balancing the output on 40 and 20 meters is part of the test procedure. You
>needed to squeeze the turns on L2 a tad. 
>
>Ron AC7AC
>-----Original Message-----
>From: Phil Wheeler [mailto:[email protected]] 
>Sent: Friday, November 28, 2003 6:18 PM
>To: Ron D'Eau Claire
>Cc: 'Alan WB6ZQZ'; [email protected]
>Subject: Re: [Elecraft] KX1 still Low Power
>
>
>I just did my initial testing and am getting a bit less out than I would
>like using a dummy load and a very accurate digital qrp wattmeter (don't
>recall the name of the kit I built it from).
>
>Using 13.8 V supply, I'm getting 2.6 W on 20 m and 3.5 W on 40 m.  The 40 m
>number is OK, but I would expect more than 3 W on 20 m.  Since this is not
>grossly off, I doubt if it relates to toroids or anything like that, unless
>turn spacing would make for small changes.  And R4 is Full CW (I know
>because I started with the other full CW -- need to understand clocks better
>-- and had zero power out).
>
>Looks like it is time for the "33 ohm solution" :-)
>
>Since I don't have anything near that at hand (should have bought one on the
>way back from my impromptu doctor visit), I will start building the options
>tonight and do the resistor change tomorrow. 
>
>Very happy with RX performance, by the way.  Seems hot and the filter can
>really get pretty sharp.  Plus really easy to tune in 20 m SSB stations and
>the like.
>
>73, Phil
>
>
>
>  
>


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