### NFB = Negative feedback. 3 db of NFB means you also reduce the gain
of the amp by 3 db. On paper,
to achieve say a 10 db improvement in IMD, you require 11 db of NFB.
## 6 db of NFB on a SB-220 means you now require quadruple the drive
power. NFB will work on a SS amp, since the
gain is sky high to begin with.
Jim VE7RF
-----Original Message-----
From: Catherine James
Sent: Tuesday, April 25, 2017 6:05 AM
To: amps@contesting.com ; W4TVJoe Subich ; Jim Thomson
Subject: Re: [Amps] Price per Watt Conversation
Joe Subich, W4TV <lists@subich.com> wrote:
Jim Thomson wrote:
Baffles me how SS marine xcvrs all have superb IMD...and also run on
11-15 vdc. Are they using loads of NFB ?
Yes. Along with little to no compression and making sure that the IF
stages aren't over driven.
Sorry, what is "NFB"?
Be careful with those TLAs. :-)
73,
Cathy
N5WVR
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