Topband: pre-selector/filter

[Dennis OConnor]

I am assuming that this preselector is passive... If it is an active device, forget it - all it is going to do is overload and create intermod...
  Now, if it is passive, then it is likely to help... The problem with todays radios is that the front ends are wide open barn doors with 500kc, or more, of signals all beating on the RF amp and 1st mixer at the same time, creating endless mischief...
  In the old days 
  ( wait, my nurse has to wipe the dribbles from my chin before they get on the keyboard) 
  anyway, as I was saying we used to have either a manually adjusted preselector in front of the RF amp, or one that was ganged to the main tuning dial and tracked across the band...  Some of the better receivers had 2,3 and even 4 cascaded tracking filter sections in the front end...  Tuning the multiple variable caps/sections on the filters so they tracked properly was a job...
  I have the MK-V and the preselector they call VRF does work well...
   
   


denny / k8do
       
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