[AMPS] G2DAF - final comments?
Lars Harlin
harlins@swipnet.se
Tue, 3 Nov 1998 04:24:04 +0200
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Lets try a different approach.
=20
I=B4ve built two DAF amps. The third is on its way. I cant guarantee =
that the measurements I=B4ve done are 100 percent
sientific, but they all point in the same direction.
=20
* On air tests
* Two tone measurements
* Spectrum analyze of voicesample
=20
All showing good to excellent linearity and some of you have already =
seen those plots. Am I wrong?
I dont claim class C efficiency, rather about the same as AB2.
=20
I=B4ve not put any effort into selecting timeconstant in screen =
filtering, so my guess is that it=B4s not especially critical.
Anyhow, to describe exactly how the DAF circuit operate is quite =
complex. I can=B4t do that, but I do know that it works,
and works fine! In SM there are 4 or five more DAF amps active on the =
bands, and in my opinion they all sound good and
do not splatter. And I consider myself to be quite critical when it =
comes to splatter and broad signals.
=20
Putting an equalsign between DAF and class C is definitely wrong!
=20
I=B4m not saying that DAF is so much better than everything else, maybe =
just as good, and apart from that; a clever design.
=20
So if anyone, in a constructive matter, could bring a bit more light in =
how the DAF ckt operates electrically when it comes to
linear amplification, I=B4ll be very interested. If not, I guess we have =
reached the far end on this subject!
=20
Now, I=B4ll go back to my #3 project. Have some work to do!
=20
73 de Lars/SM3BDZ
=20
=20
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<DIV><FONT color=3D#000000 size=3D2>Lets try a different =
approach.</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2></FONT> </DIV>
<DIV><FONT color=3D#000000 size=3D2>I´ve built two DAF amps. The =
third is on=20
its way. I cant guarantee that the measurements I´ve done are 100=20
percent</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2>sientific, but they all point in the =
same=20
direction.</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2></FONT> </DIV>
<DIV><FONT color=3D#000000 size=3D2>* On air tests</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2>* Two tone measurements</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2>* Spectrum analyze of =
voicesample</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2></FONT> </DIV>
<DIV><FONT color=3D#000000 size=3D2>All showing good to excellent =
linearity and some=20
of you have already seen those plots. Am I wrong?</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2>I dont claim class C efficiency, =
rather about=20
the same as AB2.</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2></FONT> </DIV>
<DIV><FONT color=3D#000000 size=3D2>I´ve not put any effort into =
selecting=20
timeconstant in screen filtering, so my guess is that it´s not =
especially=20
critical.</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2>Anyhow, to describe exactly how the =
DAF circuit=20
operate is quite complex. I can´t do that, but I do know that it=20
works,</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2>and works fine! In SM there are 4 or =
five more=20
DAF amps active on the bands, and in my opinion they all sound good=20
and</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2>do not splatter. And I consider =
myself to be=20
quite critical when it comes to splatter and broad signals.</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2></FONT> </DIV>
<DIV><FONT color=3D#000000 size=3D2>Putting an equalsign between DAF and =
class C is=20
definitely wrong!</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2></FONT> </DIV>
<DIV><FONT color=3D#000000 size=3D2>I´m not saying that DAF is so =
much better=20
than everything else, maybe just as good, and apart from that; a clever=20
design.</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>So if anyone, in a constructive matter, could bring =
a bit more=20
light in how the DAF ckt operates electrically when it comes =
to</FONT></DIV>
<DIV><FONT size=3D2>linear amplification, I´ll be very interested. =
If not, I=20
guess we have reached the far end on this subject!</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>Now, I´ll go back to my #3 project. Have some =
work to=20
do!</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>73 de Lars/SM3BDZ</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT color=3D#000000 size=3D2></FONT> </DIV></BODY></HTML>
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