[Milsurplus] ARR-15 selectivity

Jim Whartenby old_radio at aol.com
Mon Oct 16 00:45:54 EDT 2023


HueEnclosed is what I did to narrow the IF bandwidth of the ARR-15.  Pretty easy to series connect identical value coupling caps to the original three caps to reduce the IF Bandwidth from about 15kc to 7.5kc or so.  Look it over and see if it makes any sense.
Removing the DC line to the Audio Filter will disable the narrow audio in the CW mode so SSB is now a snap to receive.  Just offset the BFO a few tics from the zero center.
I don't have an ARC-2 manual so not sure if the IF amplifier scheme is the same as the ARR-15.  If it is similar then there should be no problem to duplicate the above in the ARC-2.Regards,Jim
Logic: Method used to arrive at the wrong conclusion, with confidence.  Murphy 

    On Sunday, October 15, 2023 at 10:40:35 PM CDT, Hubert Miller <kargo_cult at msn.com> wrote:  
 
  
Has anyone a good link to the article describing how to tighten up the ARR-15 selectivity ? It had to do with decreasing the IF coupling caps.
 
I mean RETAINING the variable IF, NOT using a 500 kHz mech filter.
 
NOT the silly audio filter thing mentioned in some silly conversion article.
 
I am also wondering how well this idea would work out on the ARC-2.
 
-Hue Miller
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