2 uV is approx. -107 dBm 100 meter path loss at 400 MHz: 64.5 dB Assuming 10 mW (.01 W) transmit power and using dipoles (approx 2 dB gain each end): Power input to matched receiver: 8.95 nano-watts = -50.5 dBm Matched receiver (50 Ohm) input volts: 668.86 micro-volts Looks liie you would be in the green ... Above resutls derived from program: LINOSITE "Line-of-sight radio links up to 500,000 km and 90 GHz. Aperture, beam widths, etc." http://www.webbworks.com/crstrode/calcs/rfcalcs.htm RF Jim ----- Original Message ----- From: "Jinx" To: Sent: Monday, October 07, 2002 6:47 PM Subject: [EE]: Calculating RF power at a distance > I'm trying to set up a network of PICs that chatter to each other > via RF. Everything is ticketyboo so far, but I'd like to know how > to calculate the transmitter power to meet the requirements of > the receiver. Say the receiver has 2uV sensitivity, and the distance > between PICs is 100m - what minimum wattage would the > transmitter be ? I'm guessing the inverse square law is the guide, > and V/m too. I've looked up RF calcs with no practical success, > so if anyone can offer real-world help that would be appreciated > > -- > http://www.piclist.com#nomail Going offline? Don't AutoReply us! > email listserv@mitvma.mit.edu with SET PICList DIGEST in the body > > -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body