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<p>Riho, most PA designs are using the fundamental work of Helge O.
Granberg, OH2ZE/K7ES, who published in the 80's a lot of ANs in
the famous Motorla 'cook book'. Helge - sk meanwhile - was a
impressive engineer and I gladly recall some meetings with him.</p>
<p>Nevertheless physics is incurruptible. If you go for IMD
optimization you have to consider a lot of details. To produce
'dirty' power is no big deal. But even 'dirty' amps can be cleaned
using Warren's fine adaptive predistortion algorithm.</p>
<p>73, Helmut, DC6NY<br>
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<div class="moz-cite-prefix">Am 09.11.2021 um 11:59 schrieb Riho B.,
ES7AAZ:<br>
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<div dir="ltr">Hi Helmut,<br>
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thank you for your remarks. I'll take a look into the bifilar
choke for DC feed. This amp is designed by OH7SV, OH2NLT. It
should be a working thing and give a quite flat 22dB gain from
1 to 60MHz. The same guys who designed the JUMA DC TRX and
state-of-art LDMOS 1kW amp JUMA PA1000 - <a
href="http://www.jumaradio.com/" moz-do-not-send="true"
class="moz-txt-link-freetext">http://www.jumaradio.com/</a>
But yes, I built it from quite a scratch. There was no big
story about this amp - schematic, PCB 2400dpiPDF image, PCB
layout, some pictures and their measurement results on their
website. <br>
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<div dir="ltr"><i><font color="#666666">73,</font></i>
<div><i><font color="#666666">Riho ES7AAZ</font></i></div>
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