[amsat-bb] Antenna Question

[Zach Metzinger]

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