Hi Scott, NX7U
Your calculation is correct.
Just for information if 0.11 uV is the applied voltage across an input impedance of 50 ohm to get the sensitivity for 10 dB S/N the following formula is very useful to calculate the corresponding NF in dB
-6 2 ( Vin x 10 ) x 20 NF = [ 10 log ------------------------ ] + 174 dB 10 BW x S/N
Where:
Vin = applied voltage in uV over 50 ohm BW = Bandwidth in Hz S/N = 10 dB Signal to Noise ratio expressed in factor = 10
In fact if you put in the above formula Vin = 0.11 uV ; BW = 3000 Hz S/N = 10 ,then you get a NF = 3.06 dB
If the receiver sensitivity is given in uV for a ratio of (S/N)/N instead of a ratio S/N the conversion formula is
(S/N) S/N = ------- - 1 (in factor and not dB) N (12 / 10 ) Example: (S/N) / N = 12 dB = 10 = 15.84 (in factor)
S/N = 15.84 - 1 = 14 .84 (in factor)
For more detais about the above formula see Ham Radio Magazine April 1980 page 71 " Noise Figure Relationship" by I.L. McNally, K6WX
73" de
i8CVS Domenico
----- Original Message ----- From: "Scott Townley" nx7u@cox.net To: amsat-bb@amsat.org; "ubong ukommi" uukommi@yahoo.com Sent: Wednesday, August 08, 2007 10:05 PM Subject: [amsat-bb] Re: ICOM 910H
The RX specifications are
SSB/CW 0.11uV for 10dB S/N ...if the noise bandwidth is around 3kHz then that's a 3dB noise figure FM 0.18uV for 12dB SINAD ...if the noise bandwidth is around 5kHz then that's a 3.4dB noise figure
-- Scott Townley NX7U Gilbert, AZ DM43di
---- ubong ukommi uukommi@yahoo.com wrote:
Hello, Please could you help me with the Noise figue of the receiver 910H. I
want to use it for a link budget analysis.
I have tried available sources but no solution. Thanks.
Ubong (M3UIU)
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