On 2019-07-26 17:04, Greg D wrote:
There is also the effect of the reflection off the Earth that can add 3db to your received signal on low passes. I believe this is well used by EME operators. But I don't think that fully makes up for the distance penalty. There is also the effect that the satellite's radiation pattern isn't necessarily equal in all directions, and other than the ISS, most are tumbling somewhat at random. That, I think, could be the main cause of the different signal reports.
Hello Greg,
Using the calculator over at pasternack.com for 70cm:
2000 mile Free Space Path Loss: 155.4 dB 400 mile Free Space Path Loss: 141.4 dB
I suspect he's referring to audio loudness, since the FM threshold effect would be in play once the CNR was > 8dB (assuming narrowband FM).
--- Zach N0ZGO