[eagle] Passband Ripple - Latest Modifications and Test Results

[Juan Rivera]

John,

 

Per your request I have modified the input coupling to the 2nd Mixer as
follows:

 

*         Remove C37

*         Replace L15 and L16 with 16 ohm resistors

*         Install 0.27 µH inductors from pins 2 and 3 of U8 to ground

 

I then retested the IF passband ripple by sweeping a 1 MHz span centered on
10.7 MHz.  The output level was reduced by 3 dB but there was no change in
the ripple.  Click HERE
<http://www.juanr.com/pages/hobbies/ham_radio/Eagle/passband_ripple.htm>  to
view my log.

 

I think we need to look outside of that coupling area since we’ve pretty
much replaced every component.  Let’s replace both SAW filters next.  What
do you think?

 

73,

 

Juan

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://amsat.org/mailman/private/eagle/attachments/20070807/b7b236f7/attachment.html