On Fri, 9 Jul 2010, tomnevue wrote: > Has anyone made a VHF repeater using 2 Delta or Rangr radios? Were the > results OK? Any unexpected problems?
Yes, two Rangrs. I turn the TX power down to 50W (100W radio) and provide forced-air cooling in an air-conditioned room. No issues noticed other than deviation being low. I used the Mic input for the transmitter and the Audio_PA_Enable line in the control head for the RXCOS line. The radios are handling time-out timer (three minute max :-/) as well as CTCSS reception and generation. This machine has a fairly low duty cycle. In testing, it would back down to 35-40W or so and just stay there when the PTT was wired to ground. Kept it locked in transmit for 24 hours, no real issues noticed (again, at 50W, it backs to about 35W, which is sufficient to keep the heatsink cool). I mounted the radios vertically, with the heatsink up. -- Kris Kirby, KE4AHR Disinformation Analyst