[hpsdr] Interesting email on SDR transmit noise

[KA5FPT Paul]

I saw the following on the Flexradio mail list. I am having some 
problems understanding how a SDR transmitter can cause wide band noise. 
I would have thought that with proper filtering it would be controlled.
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Date: Wed, 16 Oct 2013 14:59:37 -0400
From: "Gedas"<w8bya at mchsi.com>
To:<flexradio at flex-radio.biz>
Subject: [Flexradio] Noise Sidebands, Article by SM5BSZ
Message-ID: <399ADD464530473F88C1CBF0659768F5 at biggy>
Content-Type: text/plain;	charset="utf-8"

I came across this interesting article by SM5BSZ who discusses some possible transmitter issues with many radios, including the Flex.  It has me a bit concerned.  I am wondering if anyone has seen similar data for the Flex 5000? The article may be found here:

http://www.sm5bsz.com/dynrange/dubus313.pdf

Gedas, W8BYA
Gallery athttp://w8bya.com
Light travels faster than sound....
This is why some people appear bright until you hear them speak.

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73,
Paul Cecil
KA5FPT