Topband: BOUNCE topband@contesting.com : Approval required: taboo header: /^cc:\s*.+/i

Bill Tippett btippett@alum.mit.edu
Mon, 05 Mar 2001 10:45:21 +0000


Message-ID: <091d01c0a55f$5bc22460$6401a8c0@neptune>
Reply-To: "Michael Tope" <W4EF@dellroy.com>
From: "Michael Tope" <W4EF@dellroy.com>
To: "Bob Marshall-Read" <rmread@attglobal.net>, <topband@contesting.com>
Cc: "N6ET" <Robert.Polansky@jpl.nasa.gov>
Subject: Re: Topband: FT-1000D Noise Figure
Date: Mon, 5 Mar 2001 02:30:53 -0800

I wrote:
> > Does anyone know the typical noise figure of the FT-1000D on
> > 160 meters when it in the high gain (versus AIP position)?

Well, nobody answered my email, so I looked up the MDS (minimum discernable
signal) specs from the test reports on the ARRL website. I am not sure of
the proper convention for determining MDS, so I assumed that MDS = 0 dB S/N
ratio and worked backwards to determine the receiver's noise figure. With a
measured MDS of -138dBm thru 250 Hz filters (pre-amp on), I got a noise
figure of 12 dB (-138 dBm - [-174 dB/Hz + 10*log(250)]).

I needed to know, as I am trying to figure out if an external pre-amp will
offer any advantage when used with the flag antennas my friend Bob and I are
going to install at the local club station. 

Hope this is helpful. 

Mike, W4EF


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