[hpsdr] HPSDR front end

[Eric Ellison]

Hi Francis and Phil

 

Phil! Really nice write-ups on all the projects! 

 

http://hpsdr.org/index.html

 

Eric

 

 

  _____  

From: hpsdr-bounces at hpsdr.org [mailto:hpsdr-bounces at hpsdr.org] On Behalf Of
Phil Harman
Sent: Saturday, March 11, 2006 10:35 PM
To: FRANCIS CARCIA; hpsdr at hpsdr.org
Subject: [hpsdr] HPSDR front end

 

Hi Francis,

 

You asked 

 

"What is the front end of this FPGA machine you guys are building.?"

 

There are two options being considered at the moment. The first is direct
A/D at the antenna using the Mercury board ( see http://hpsdr.net under
Mercury for a brief description) and a more conventional mixer +  local
oscillator down converter to  the  Janus  "sound card replacement" A/D
converter. 

 

At the moment it looks very unlikely that the mixer will be a QSD due to the
20dB odd increase in NF from 2 to 30MHz that this mixer suffers from. 

 

I'm presently working on a replacement mixer, still using bus switches, that
does not have this problem. Early results are very encouraging.  More
details to follow.

 

73's  Phil..VK6APH 

 

 

 

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