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RE: [linrad] A simple front end

Hello again Roger
I note that the R2Pro site prices the modules individually.
LNA  (specify band)	$12
Down converter		$52
Analog processor		$38
1 kHz filter		$15
3 kHz filter		$14
Audio amp		$16

All together for $115- pretty good value it seems to me

Boards only $25

Thank you Leif for the tip about a cheaper way to get the +/- 45 
degree phase shifts. I calculated the relevant component values for 
14 MHz as I want to try the DC design for the first time.

>Hi, Leif!
>Welcome back!
>Yes, your "?????" and what you say [excerpted below] is really the point I was
>To make a longer note to explain what I was saying in the original email:
>The R2Pro consists of, in order of signal transit:
>Low Noise Amplifier Board
>DownConverter Board: TUF3's in quadrature followed by diplexer, etc.
>Analog Signal Processor Board
>Audio Filters
>Audio Amplifier Board
>The DownConverter Board has its diplexers just after the TUF-3's, 
>and they roll off
>quickly [4000 Hz?].
>So you are I believe using only the RF amplifier board and the 
>TUF-3's and throwing
>away everything else if you use the R2Pro for Linrad.  This makes this route a
>relatively financially inefficient way to go and wastes a lot of 
>parts and effort.
>I couldn't see taking the R2Pro and using just the RF amplifier and TUF3's and
>wasting the boards and everything else.
>It would of course be possible to redesign things and change the 
>frequency response
>of the DownConverter Board from 0-4000 Hz to 0-90 KHz, and alter the 
>stages as well, but I felt that if I was going to do all that, it 
>would be just as
>well to start from scratch.  Thus my comments.
>It would be possible to use just the LNA board with no mods followed 
>by the remainder
>of  your own front end, but buying the R2Pro just to get the LNA board is an
>expensive way to go vs just building that alone.
>There are some pages on the R2PRo at:
>They don't have the schematics.  I DO have the schematics, but I don't have
>permission from Rick to post them.
>>  > It is the audio phase-shift network
>>  > and diplexer that I thought would not have the necessary bandwidth.
>>  ????? These parts should be bypassed. Do not sum the signals in the
>>  analog hardware - that is for Linrad to do.
>Any and all comments / corrections are appreciated!
>Roger Rehr