Nov 20, 2005 #1 S seadolphine2000 Advanced Member level 3 Joined Apr 12, 2005 Messages 880 Helped 122 Reputation 244 Reaction score 87 Trophy points 1,308 Activity points 7,372 I have an FM Tx that produces power of about 200mW with antenna elevated about 15 meters above the ground. What is the value of the air attenuation constant (α).??? Thanks very much for your consideration.
I have an FM Tx that produces power of about 200mW with antenna elevated about 15 meters above the ground. What is the value of the air attenuation constant (α).??? Thanks very much for your consideration.
Nov 23, 2005 #2 tapa Super Member Joined Feb 17, 2002 Messages 133 Helped 8 Reputation 16 Reaction score 5 Trophy points 1,298 Location spain Activity points 1,096 Re: Ateenuation constant of air realy you need the "free space atenuation" L=(lamda/(4*pi*R))^2 of course the information of the TX and RX antennas If you do not consider any propagation effect except the free lost the equation is: L[dB]=32.4 + 20 log d[Km] + 20 log F[MHz] Prx[dBm] = Ptx[dBm] + Gtx[dBi] - L[dB] + Grx[dBi] I hope it helps you TaPa
Re: Ateenuation constant of air realy you need the "free space atenuation" L=(lamda/(4*pi*R))^2 of course the information of the TX and RX antennas If you do not consider any propagation effect except the free lost the equation is: L[dB]=32.4 + 20 log d[Km] + 20 log F[MHz] Prx[dBm] = Ptx[dBm] + Gtx[dBi] - L[dB] + Grx[dBi] I hope it helps you TaPa