Roy Witt writes in a message to Scott Christensen
 SC>   The one gotcha is that they use under or over injection based on
 SC> the frequency range that you are in - because of image rejection
 SC> issues.  You really need a manual to figure out the exact crystal
 SC> frequency because of this.
 RW>  So if she's converting a commercial band radio to ham band, 
 RW> she'll need to know which frequency range the radio's in? As 
 RW> in 450 to 460 vs 460 to 470MHz.
I don't know what the splits are on a HT90 or 440, or if there are any, 
however, there is a chart in the maintenance manual that details the ranges 
and whether there is high or low frequency local oscillator - it seems to me 
that the second LO also flips from high to low in those ranges too.  And if 
you are using digital PL, there is a jumper on the PL board that may have to 
be installed or cut to deal with the inversion that happens when the 
injection is changed from high to low or vice-versa.  Like I say, I don't try 
to memorize every radio I work on, just what the pitfalls are.  Then I look 
it up in the book.
  
I suggest that the person working on this radio actually invest in the 
maintenance book.  It will prevent a world of problems down the line.
 
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