kb3ccn wrote: > i have a question that hasn't been really answered by my searches .I > am building a gm300 repeater for local GMRS usage. Would it be > better to open the squelch on the rcvr and allow the tone to do the > muting until it detects the carrier with proper tone? > > Thanks Keith N3QAM >
No. Nearly all CTCSS decoders false to one degree or another, so your repeater will trip occasionally on falses. Using the COS line will add a level of 'validity' to any signal that brings up the repeater, ie, it has to both open squelch AND have the right tone. Another good reason is that likely, unless users have reverse burst, and your decoder/tone panel recognizes it correctly (not a lot really do), you will hear a pretty lengthy squelch crash when users unkey, however long it takes the decoder to 'spin down', frequently a half second or more. 'And-ing' the COS in will usually shorten that up quite a bit to maybe 50-300 mS. Much easier to listen to. Jim WD8CHL/KAE9169
