At 02:33 PM 5/21/05, JOHN MACKEY K0SSF <[EMAIL PROTECTED]> wrote: >OK Mike (WA6ILQ), I am reading on the repeater builder web site about the >Mitrek PL (HLN4181) board. I have a 10 Meter FM remote base connected to my >repeater via an RLC-3 controller. I CURRENTLY use the HLN4020 dual element PL >board in my 10FM remote base & am strongly considering swapping it for the >reedless HLN4181 board due to the ease of changing PL. I know I could simply >put a Comm-Spec board in, but using the HLN4181 saves money (since have one >currently collecting dust) and it would give me reverse burst no metter what >tone I am using. (Rev burst is nice because I occasionally access another >remote base across the countty during band openings, and our two remotes using >the same PL with rev burst is really nice!!) I could simply set the reedless >board up with a couple of different tone options & switch resistor networks on >the fly.
You will need a 2-pole relay to do that - switch the two strobe pulses. >On the web site regarding the HLN4181 reedless board you state: >"There is also an audio notch filter on the board to remove the received PL >tone from the received audio. However it's a pretty poor design and you >don't want to try to use it in repeater service - just plan on using an >external high-pass filter between the receiver and your repeater controller" > >So, Mike, what exactly is the proble with the Mitrek high-pass filter? It's a shunt gyrator design tuned to roughly 134hz. Picture a series LC network tuned to 134hz and shunted across the RX audio. >Is is any worse that the other moto PL board high pass filters? Much worse. The Mitrek is a low-Q notch, the Micor and Motrac at least had real inductors in a true high pass / low cut filter. Go yourself a favor - grab a Micor RX PL board or a GE M2 repeat audio card (from a station shelf) and copy the highpass audio filter. >I know I could simply pick the audio off the discriminator BEFORE >the PL filter, but I don't do that. I always use a PL filter BEFORE >the audio goes into my controller so the PL tone does not get >repeated I with others would do that. >& cause other problems. BTW look at <http://www.repeater-builder.com/mitrek/mitrek-interfacing.html#Audio_Out> for more tricks on Mitrek repeat audio (the link is into the middle of a writeup on the Mitrek). Mike WA6ILQ PS - Note to John: do you think that Silke would do a writeup on the RCA-700 interfacing? Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
