This sounds like a dual squelch system which sets a higher level for non pl signals and a lower one for those with pl.  It sometimes works unless the intermod is stronger than the higher of  these settings.  With the sensitivity of  today's equipment and the broadband nature of their design coupled with the massive use of PLLs that naturally generate birdies it seems all services are fighting the same thing.  

I had a series of KDK radios which not only were blind friendly (I would give my left.... for am fm240 or 440 with speech boards,) employed some avionics type circuits that tuned the radios for the frequency  of operation at any given time and the intermod was vastly reduced even compared to my newer radios today.  It is too bad that company did not garner more of the market.  For the time I really thought they were worth the money.




Thank You!

BRETT K WINCHESTER  PM  KD7JN

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>>> JEFFREY MICHAEL KENYON <[log in to unmask]> 01/09/02 11:42PM >>>
Hi everyone, I have had a weird situation come up with a couple of 2-meter
repeaters and 440 repeaters.  Some that claim that you need a 100 or 107.2
Hz PL tone I've been able to access with both the PL and without.  This
doesn't make sense if they want to clear out interference.  Has anyone
else noticed this?  I figure it is either one or the other.