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See also KNB2 Notes

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Date: Wed, 21 May 2003 07:53:10 -0700
From: Wayne Burdick <n6kr at elecraft.com>
Organization: Elecraft
To: James1787 at aol.com
Cc: elecraft at mailman.qth.net
Subject: [Elecraft] Re: K2 Noise Blanker Question


James1787 at aol.com wrote:

> I got the "Not Inst" message when I tried to use the Noise blanker. 

James,

This would be caused by either an open or short on one of the pins of U3
(12C509A) or a defective U3. Examine all of U3's pins and related components
with a magnifying glass to make sure they're soldered cleanly. Make sure you
have approx. 6V at pin 1, and between 5 and 6 V at pins 3 and 4. Also
double-check the value of R6 (220 ohms) and C9 (.001).


> There was no mention as to what to do with R90. 
> Do I install a jumper here or do I leave it as is? 

R90 is no longer needed once the noise blanker is installed. 

73,
Wayne
N6KR

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