Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronic Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

Receiver for NOAA weather satellite

Status
Not open for further replies.

Actionscript

Newbie level 4
Joined
Mar 5, 2011
Messages
5
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,316
Hi,

I am new at RF. I read from books that the IF can be shifted by mixing a frequency with the input frequency.
I am curious that there's 87-107MHz IC. If I mix the 137Mhz input with an oscillator, say, 45Mhz, is it possible to get the sounds signals from the satellite?

Thanks.
 

RCinFLA

Advanced Member level 2
Joined
Aug 31, 2010
Messages
590
Helped
187
Reputation
378
Reaction score
186
Trophy points
1,323
Activity points
5,698
A commerical FM receiver will have too wide a bandwidth. The old NOAA system uses a narrow bandwidth FM. The channel bandwidth is about 50 kHz. This is in comparison with 150 kHz for commerical FM and 20 kHz for a normal FM communications scanner which is too narrow.

Your best bet is to convert to 10.7 MHz I.F. and get a filter of 50 kHz to 60 kHz nose bandwidth. The demodulator can be a quadrature detector, just raise the Q of the quadrature coil circuit to reduce the bandwidth which will increase the recovered signal level.
 

betwixt

Super Moderator
Staff member
Joined
Jul 4, 2009
Messages
14,717
Helped
4,810
Reputation
9,638
Reaction score
4,591
Trophy points
1,393
Location
Aberdyfi, West Wales, UK
Activity points
125,363
Might be worth checking the broadcasts are still running. Several satellites have gone completely digital now and it is very difficult to decode the data.

Brian.
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top