RE: [linrad] Mixer design - comments please

["Robert McGwier" <rwmcgwier@xxxxxxxxxxx>]

The IQ outputs are sine and cosine.  You need
square wave.

Bob
N4HY


-----Original Message-----
From: owner-linrad@xxxxxxxxxxxxxxxxxxxxxx
[mailto:owner-linrad@xxxxxxxxxxxxxxxxxxxxxx]On Behalf Of Edson Pereira
Sent: Tuesday, July 08, 2003 04:41
To: linrad@xxxxxxxxxxxxxxxxxxxxxx
Subject: Re: [linrad] Mixer design - comments please



Hi Alex,

Since the input range of some soundcards can be in the range of 10 vpp, it 
may be better to use a 10V supply for the Op-Amps. You may also consider 
using the NE5532 instead of the NE5534 to lower the component costs.

What type of LO source are you planning in building? 

Looking at the DDS schematics presented in the SDR-1000 article, I don't
understand why Gerald used lowpass filters and than a comparator if the
DDS already has a square I/Q output.

73,

-- Edson, 7n4ncl



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