Hi Fitri ,
The sensitivity of Yaesu FT-847 at 144/430 MHz with preamplifier ON is 0.125 uV for a S/N ratio of 10 dB into a Bandwidth of 2400 Hz in SSB
To convert the above sensitivity into Noise Figure NF in dB we can use the following formula: -6 2 ( Vin x 10 ) x 20
NF = [ 10 log ---------------------------- ] + 174 dB 10 BW x S/N
Where: Vin = Applied input voltage in uV over 50 ohm RX input impedance BW = Bandwidth in Hz S/N = Signal to Noise ratio in power ratio and not dB
Working the numbars for a FT 847 in SSB we get:
-6 2 ( 0.125 x 10 ) x 20 NF = [ 10 log ------------------------- ] + 174 = 5.14 dB dB 10 2400 x 10
A Noise Figure NF = 5.14 dB in SSB with preamplifier ON is a good value.
73" de
i8CVS Domenico
----- Original Message ----- From: "Fitri Rahmawati" [email protected] To: [email protected] Sent: Sunday, October 04, 2009 10:27 AM Subject: [amsat-bb] NF
hi, sorry I'm new
how exactly NF at Yaesu FT-847 transceiver for UHF 437,325 mhz ( 69 cm ) ?
Thank's Fitri Rahmawati - Indonesia
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