I haven't used one of those, but I'd ask, what is it doing differently? If you invert the phase of the tone 180 degrees (or 120 for some older motorolas), it should mute correctly. The only issues I've ever run into is either the transmit delay is too short (ie, TK-x05D series), and the rx squelch doesn't have time to close all the way, or it's too long and the rx squelch closes, then opens back up again before the tx goes off the air. Or the decoder just plain old doesn't recognize it (most ham rigs). The worst is the VX-1R that, once it decodes the right CTCSS tone, it stays open until the signal goes away. If you drop tone, it'll stay open indefinitely, until you drop carrier.
-- Jim Barbour WD8CHL skipp025 wrote: > Re: Reverse Burst Comments (Com Spec RB-1) > > If you add a circuit like the Com Spec RB-1 board to the typical > repeater system using a ts-32/ts-54 board... the tx ctcss is not > disabled or removed before the RB-1 delayed ptt line drops. > > So you have the phase inverted ctcss present for at most up to > 200 ms typical before the tx drop. If you don't remove the ctcss > source the inverted ctcss remains up until the tx off/drop... > > Any of you actually running the RB-1 board with a true reverse > burst type ctcss decoder (built into your radio)? Is a true > reverse burst decoder in your commercial radio completely "fooled" > by the phase inverted ctcss before carrier drop function. > > Or do you actually still hear some minor difference from the > rb-1 type operation vs an original true Motorhead (Motorola) > encoder - decoder operation? > > Thinking out-loud about having to possibly mute the ctcss at some > time after invert and before the delayed ptt drop as a requirement > to get the full/true reverse burst quiet squelch close. > > Any of you been down that road already? > > skipp
