View Single Post
  #8   Report Post  
Old October 12th 06, 02:53 AM posted to rec.radio.amateur.homebrew
Wes Stewart Wes Stewart is offline
external usenet poster
 
First recorded activity by RadioBanter: Jul 2006
Posts: 71
Default effect of cascading LNAs

On 11 Oct 2006 12:13:20 -0700, wrote:

I asked what I don't know. I am expecting a helpful answer.


The problem was, you got some prior answers and then wanted to argue
about it.

The frequency is 70MHz.


Then, assuming some type of filtering around that frequency that's
more or less where your system will likely oscillate.

One reason superhetrodyne receivers were developed to replace TRF
receivers was to develop system gain at different frequencies so as to
minimize the chance of oscillation. Another, of course was to achieve
better selectivity that with older technology was better accomplished
at lower frequencies.

Even a single conversion receiver usually develops its gain at three
different frequencies: r-f, i-f and post detection.