--- In Repeater-Builder@yahoogroups.com, "Bob M." <msf5kg...@...> wrote:
" I believe the Motorola DTMF decoder resides in an expansion chassis. ... As you said, both are rare and none of the stations I need to control have an expansion chassis. ... The other suggestions, while innovative, don't seem to decode DTMF, which is what I want to use to control the repeaters. ..." -------------------------------------------------------------------- Expansion chassis aren't really all that hard to find, I have gotten several off that e auction site, as a matter of fact there is a current listing of two for $40 buy-it-now. As regards DTMF, the Maxtrac does a fine job of decoding DTMF as I said in my original response: "...to have the Maxtrac decode DTMF you need a small option board or you need to duplicate that circuit on a perf board. ..." That option board is available from Motorola parts for $64.60 ready to go, but knowing that hams are cheap, as an alternative I suggested a DIY version on perf board - it's pretty simple - it consists of 2 IC's, a 145436 decoder chip and a 4021 CMOS shift register plus a 3.58 crystal and a few resistors & caps.
