| |
G0FTD > INFO 19.03.03 23:45l 39 Lines 1624 Bytes #999 (0) @ WW
BID : 350665G0FTD
Read: DB0FHN GUEST
Subj: Re: More Pioneer 10 info.(G0FTD).
Path: DB0FHN<DB0RGB<OK0PPL<RZ6HXA<SP7MGD<GB7YKS<GB7MAX<GB7COV<GB7COV<GB7CIP<
GB7SXE
Sent: 030319/2125Z @:GB7SXE.#38.GBR.EU #:13061 [Hastings] FBB7.00i $:350665G0FT
From: G0FTD@GB7SXE.#38.GBR.EU
To : INFO@WW
G0TEZ wrote:-
> The other thing that struck me was just how noise free the RX must be and
> how good the aerial to detect such a weak signal.
The antenna's noise factor reduces in space because free electron
movement is reduced. You have to work out the area that the antenna
covers as in square metres kind of thing, and with the temperature
figure and rx bandwidth you can come up with a figure of watts per hertz
of noise generated by the antenna.
Same thing goes for the components in the receiver, the noise figure
is reduced too.
What we don't know is the performance of the receiver, I mean in them
days they were probably using passive components like carbon resistors,
which have a higher noise figure than an 0402 SMD device found in a
mobile phone etc etc, so it makes life a bit difficult to predict what
the noise floor of the satellite receiver is, unless of course someone
else knows better.
In a decent component catalogue, you'll see noise figure figures
quoted for passive components as well as semiconductors.
You can upgrade the ground station receiver as technology progresses,
but not the satellite one :-)
ÚÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ¿
³ 73 - Andy ³
³ G0FTD ³
³ Psion Revo owner ³
³Msg sent 18-03-2003³
³ ÚÄÄÄÄÄÄÄÄÄÄÄÄÄ¿ ³
³ ³ Û ³ ³
ÀÄÄÁÄÄÄÄÄÄÄÄÄÄÄÄÄÁÄÄÄÙ
Read previous mail | Read next mail
| |
