It's doable. Right now you'd need a Maxon data radio with external sink for the transmit side and either another for receiver or a hamtronics receiver (about the best receiver that can practically be purchased right now). 30 ft of vertical separation and CAT5e to provide PTT, audio and COR as well as power (you'd want 24 or 48V for all intents and purposes). Still looking at $600 cost if the Maxon's were type accepted for GMRS. Add the cost of a duplexer and subtract the extra antenna and combine enclosures, you'd have a decent TTR. That's what it would cost with current tech in a reliable package though. In retrospective, Motorola sells a P25 tactical repeater (battery, duplexer at 4W) for $22,000. Etherstack on the other hand has one they are bringing to market for (15-30W depending on configuration) for $30,000. Sent from my iPhone using Tapatalk