The mitrek uses a type of passive filter. It's more of a shunt to ground type of filter rather than a series element. If you look at the PL board schematic closely, you will see where it connects through pin 7 to the radio. The schematic notes (all of the theory of operation we have in this case) says that it is a gyrator, a simulated inductance, that resonates with a .1uF cap to produce a notch at 180Hz. I never found them to work the best, but there is a kind of filter there. If anyone can tell us a more advanced theory behind how this type of circuit works, I think we (or at least *I*) might learn something.
In order to use a thru type filter, you will need to break the audio path somewhere. Be sure you feed your filter with a good low-impedance source, and feed a high impedance load with it. Scott M. Scott Zimmerman Zimmerman Electronics Amateur Radio Call N3XCC 612 Barnett Road Boswell, PA 15531 ----- Original Message ----- From: "Adi Linden" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Friday, November 21, 2003 2:11 PM Subject: Re: [Repeater-Builder] PL/CTCSS Filter > > From my recollection, the filter is used in the base station > > package - why wouldn't it be? Yes, to use the filter, JU201 needs > > to be removed or is that a problem for you? > > I am using a Mitrek not a Micor. The Mitrek doesn't have a filter on the > PL board. > > Adi > -- > Adi Linden | va3adi | [EMAIL PROTECTED] | http://adis.ca > +-----------------------------------------------------------------+ > IRLP Node 2590 in Sioux Lookout, Ontario > > > > > > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ > > > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
