I was following some bunny trails re that Chinese 50 watt amp and saw a
fairly extensive set of graphs run by one owner and they looked ok.
Sorry, I don't have the url for that. Maybe someone here knows where
they are.
-Lee-
WA3FIY
------ Original Message ------
From: "Jim Brown" <k9yc@audiosystemsgroup.com>
To: tentec@contesting.com
Sent: 3/19/2016 2:04:27 PM
Subject: Re: [TenTec] SOTA RADIO
On Sat,3/19/2016 10:39 AM, geoffrey mendelson wrote:
Both MFJ and Ten-Tec bought rights to sell them assembled, and in
order to pass FCC approval had to add output filtering. I forget
which, but one company sold them as two band radios, and the other as
single band.
I would have the same concerns about FCC approval and harmonic
suppression with that 50W amplifier being mentioned earlier in this
discussion. There's no way a ham should put either of those no-name
imports on the air without first checking them for spurs and harmonics
with a spectrum analyzer into a dummy load.
Don't have a spectrum analyzer? That's no excuse -- if there are
harmonics or spurs, YOU are in violation. Indeed, that's part of the
responsibility of having a ham license, and it's why we as hams CAN
build stuff without having it FCC approved. We should KNOW, because
we've studied, that virtually any ham amplifier creates harmonics that
must be filtered. The second harmonic in a power amp is typically only
6 dB below the fundamental before the output network filters it! But it
still must meet FCC requirements for RF cleanliness.
73, Jim K9YC
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