[GreenKeys] PLL TUs

[jhhaynes at earthlink.net]

No direct experience, but...If there isn't good filtering and limiting
ahead of the PLL then you won't get much of a TU - good for good signals,
maybe, but not much else.  So if you have a "filterless" TU then you
need a receiver with a good 200Hz or so filter in it ahead of the TU.
Otherwise the PLL is going to lock on to whatever signal is strongest
in the receiver passband, which might not be the signal you are trying
to receive.


jhhaynes at earthlink dot net