----- Original Message ----- From: "Edward Cole" kl7uw@acsalaska.net To: w3hf@arrl.net; amsat-bb@amsat.org Sent: Thursday, April 22, 2010 5:46 PM Subject: [amsat-bb] Re: Arecibo on 432 MHz Moon Bounce (some calculations)
Hi Ed, KL7UW
You writes:
In fact the first gain number published over a month ago was 58 dBi. Then I suppose a bunch of hams complained that they didn't understand isotropic gain so the Arecibo folks kindly converted the number to 60 dBd. (i.e. unity isotropic gain, dBi=0, is what a true omni-directional antenna produces in free space)
73, Ed - KL7UW, WD2XSH/45
Ed , you have reversed dBi with dBd
58 dBi cannot be converted to 60 dBd because the gain of a dipole over the isotropic antenna is 2.14 dB then 60 dBd is corresponding to 60 + 2.14 = 62.14 dBi
By the way 58 dBd is corresponding to 60.14 dBi rounded to 60 dBi wich is the official gain given for Arecibo at 432 MHz
73" de
i8CVS Domenico