[SECC] Fw: [1000mp] MP Noise Blanker Issues

[Larry Crim]

Tom,

Are you familiar with this problem in the FT-1000MP?  If so, do you know the
mod?

I know several club members who like to know.

TU & HNY,

Larry K4AB

-----Original Message-----
From: Tim Duffy <tduffy@sygnet.com>
To: 1000mp@qth.net <1000mp@qth.net>
Date: Saturday, December 30, 2000 16:25
Subject: [1000mp] MP Noise Blanker Issues


>The problem with the NB front panel control is well documented by INRAD
>in their "MP Filter Selection and Operating Thoughts" It is a  4 page
>document. The document comes when you purchase INRAD filters.
>
>The IMD is deteriorated when the NB1 and NB2 switches are in the OFF
>position and the NB pot is in anything but the full CCW position.
>
>I have received many emails telling me that operators do not see any
>difference when he front panel control is varied with the NB's in the
>OFF position. Not every receiver will be affected the same. Signal
>strength and the number off signals on a band have a direct impact on
>this problem. The only time I can hear the problem is when the bands are
>full of contest signals...It is then very noticeable,
>
>According to INRAD's excellent info, the third order intercept goes from
>+14.5 dBm at full CCW to -7.0 dBm at full CW. This test was made on 7
>MHz, tuned front end, 500/400 Hz CW filters. The difference is amazing
>(21 dB!).
>
>The mod I mentioned before takes the NB circuit out of line when the
>NB's are off and then the control has no affect on the receiver
>performance.
>
>
>73,
>Tim K3LR
>
>
>---
>Submissions 1000mp@qth.net
>
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