Thank you all for your inputs. I think I'll use the Arcom RAD design if I can get the IC they use; I prefer homebrewing...
73 de Martin HB9TZW --- In Repeater-Builder@yahoogroups.com, Jim Brown <[EMAIL PROTECTED]> wrote: > > Most DTMF decoder chips have an output that transitions when a valid tone pair is decoded. This output can be used to mute the transmit audio while the DTMF tones are present, snf most repeater controllers have the option of muting the DTMF control codes. > > In the case of a single tone, the DTMF decoder will not work. But one of the DSP audio processors will work to get rid of a single tone when it is in the 'notch' mode. I have an older Radio Shack DSP that renders CW uncopyable as only a very short click at the beginning of each element is heard. > > 73 - Jim W5ZIT > > --- On Fri, 10/24/08, cruizzer77 <[EMAIL PROTECTED]> wrote: > From: cruizzer77 <[EMAIL PROTECTED]> > Subject: [Repeater-Builder] DTMF/toneburst silencer/blocker > To: Repeater-Builder@yahoogroups.com > Date: Friday, October 24, 2008, 4:00 AM > > > > > > > > > > > > Hi > > > > I'm looking for a circuit which removes dtmf tones and maybe other > > tonebursts from the rx audio before it is fed to the tx. > > > > There are circuits around which use the MN3008 and MN3101 ics which > > are both obsolete now so are no choice. One possibility would be to > > replace them with similar ics from Coolaudio, but most likely these > > would still be hard to get even though they're still made. > > > > Does anybody have a different approach for such a tone blocker? > > > > Thanks Martin > > . >
