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From: "Uwe Wensauer" <uwe.wensauer@gmx.de>
To: <rsgb_lf_group@blacksheep.org>
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Date: Fri, 16 Jun 2006 13:56:09 +0200
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Subject: LF: Re: Re: Re: PAs
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Hello  Murray,

I assume that this message was not for me

But on the other hand, I am highly intersted in Building a LF- TX  You
metioned in the letter.
At present time I struggling in programming a Attiny 2313 as a replacement
for AT90S2313.

73
Uwe, DK1KQ


----- Original Message ----- 
From: "Murray ZL1BPU" <zl1bpu@nzart.org.nz>
To: <rsgb_lf_group@blacksheep.org>
Sent: Friday, June 16, 2006 11:55 AM
Subject: LF: Re: Re: PAs


> Uwe,
>
> It certainly looks like 2nd harmonic problems to me too, probably
linearity
> (gain) imbalance. Another thing you will have discovered is that with the
> harmonic information Peter mentioned, the SWR meter or bridge (if you use
> one) won't give good nulls, because the harmonic content won't be matched
at
> the antenna tuner.
>
> Either you need a rather better low pass filter, or to sort out the
> non-linearity. My LF TX operates in Class D (can't get more nonlinear than
> that) but the waveform is nicely sinusoidal at the antenna. Mind you,
third
> harmonic is my problem, not second.
>
> 73,
> Murray ZL1BPU
>
>