Re: [Discuss-gnuradio] AR5000 and downconversion

[Krzysztof Kamieniecki]

Alan Gray wrote:
> Sorry, I probably should have been more specific about my aims
>
> I'm looking to receive and demodulate an Australian HDTV signal. We use 
> a COFDM (Coded Orthogonal Frequency Division Multiplexing) modulation 
> scheme instead of the ATSC scheme used in the US but the bandwidth 
> requirements are approximately the same, around 6-7MHz. This, I believe, 
> rules out the possibilities of trying to use undersampling techniques to 
> sample the signals, as I don't think I can fit the entire signal into a 
> Nyquist region.
>
> I'm looking at trying to downconvert the 10.7MHz IF to a center 
> somewhere in the range of 5-6MHz, which I think should be possible 
> though I'm currently unsure if there is an IC on the market which will 
> do the job while still maintaining a decent IF bandwidth. I'm still 
> looking into the possibilities, but again, if anyone has an opinion it's 
> most welcome
>
> Alan
<snip>

I have been wondering about this sort of stuff myself. (I'm a Software Monkey)

Is there an RF EE in the house?

Is it as simple as getting an Minicircuits coaxial mixer, anti-aliasing filter, and some sort of 
Frequency source could you just connect them together with some random (impedence matched) Coax 
cables and make a simple tuner.

With a fixed 5MHz source would this be Alan's downconverter?


There must be some catches somewhere, can someone give us some details?

--
Krzysztof Kamieniecki
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