----- Original Message ----- From: "Andre" sats@pe1rdw.demon.nl To: amsat-bb@amsat.org Sent: Saturday, January 21, 2012 8:12 PM Subject: [amsat-bb] Re: Thanks for all the ...
Good point, a preamp is to cancel out the cable losses, anymore and you are just boosting the background noise and not improving the reception. So if your cable is very short there is not point in using a preamp.
73 Andre PE1RDW
Hi Andre, PE1RDW
It depends on the noise figure NF of your receiver. Lets suppose the NF of your commercial receiver is as usually in the order of 6 dB, then a preamplifier with a NF = 0.5 dB and 15 to 20 dB gain will improuve your (S+N)/N ratio even if the lenght of your coax cable between the antenna and receiver is very short.
73" de
i8CVS Domenico