[amsat-bb] Re: Planning

Grant Hodgson grant at ghengineering.co.uk
Mon Apr 30 08:05:56 PDT 2007


MKM wrote :-

 >We need new IF-DSP  V/H/SHF radios with built in band scopes and
 >modules up to 5GHZ.

and Ed wrote :-

 >The solution is to use a SDR on the IF of your current radio.  Then
 >software can provide DSP, filtering, spectral and waterfall displays,
 >decoding...etc.
 >I am testing the SDR-IQ using the 28-30 MHz output of the DEMI 144/28
 >converter.  144-MHz is very commonly used IF for microwave converters.


A more modern approach would be to use an SDR at the RF frequency, with 
direct conversion to baseband, thus eliminating the transverter 
altogether.  This is what the uWSDR (Microwave SDR) project is doing.

In a nutshell - using the latest components and modern circuit 
topologies to realise a high-performance SDR operating at microwave 
frequencies.  The first products will be for the 2.3GHz (which includes 
2.4GHz) band and a sister product for 144MHz.  The software for the user 
interface is new; the software for the low-level DSP is the same as used 
on SDR-1000 and other SDRs.

More details can be found on the uWSDR website :-

uwsdr.berlios.de

and there is a Yahoo group for the developers and lurkers.

ON/G4KLX will give a remote presentation via the web at Dayton, and I 
might be able to give a talk in person at Microwave Update.

There are umpteen possibilities for product options for satellite use, 
such as a 2.4GHz only Rx, a crossband 1.3GHz Tx/2.4GHz Rx,  etc. etc.

Development progress has been painfully slow; if anybody would like to 
help with the design and development please contact one of the team.

73

Grant G8UBN
for the uWSDR team


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