[HomeBrew] Direct conversion receiver

[flowertime01 at wmconnect.com]

Richard,

Better signal to noise and better sensitive is always gained up front. More 
gain along the way just amplifies what is already in the pipe line. Gain up 
front gets more sensitivity and more band width. Now the question is do you 
filter the extra stations out before the new front end amp or after the 
amp? Is this amp also adding lots of spurious products or is it fairly clean? 
If it is clean then put a band pass filter in after the new front end stage. 
If the new amp is allowing some spurious products because it is not linear 
or over loaded or any and all of lots of other reasons, then put a band pass 
filter ahead of the new amp.

Wide band filters are not wonderful. You may prefer a band pass filter and 
switch it for different bands. Or call it a preselect and tune it separate 
from the main tuning so you do not have to design and build a filter that 
tracks exactly with the tuning.

You are on the cusp of design. Is it a simple direct conversion or is it a 
low end simple receiver with enough stuff to get the job done? You get to 
trade a lot but nothing is free.

Good luck and keep working on it until you are happy.

Roger AI4NI</HTML>