> "Eric Lemmon" <wb6...@...> wrote: > Skipp, > I agree with nearly every point you made, having had > experience with both the Kenwood and Hamtronics repeaters. > However, Hamtronics and similar repeaters have one serious > deficiency: A total lack of PA protection against high SWR > due to antenna or feedline problems. In addition, the Hamtronics > PAs have no active power control circuitry; if the supply > voltage goes up, the output power goes up, and vice-versa. > The Kenwood TKR-x50 repeaters, on the other hand, have both > active power control and high SWR protection built-in.
Well... one might expect and/or hope a properly current protected RF PA to draw excessive current in a fault condition and trip the breaker or pop/open the fuse. It also takes a pretty hard fault to kill the PA... one "should" normally notice a power/signal level problem well before damage occurs. And of course the repeater should be operating off a Regulated Power Supply. The more famous surplus commercial radio 224 MHz conversions replace the PA with a Hybrid RF Amplifier Module... wonder if they also include SWR Protection? > I have a Hamtronics REP-200 repeater in service right now > on 224.500 MHz, and I took the precaution of hanging a single > ferrite isolator on its TX output to protect the very simple > 15 watt PA. So far, so good... > 73, Eric Lemmon WB6FLY With proper care and feeding your repeater should last for decades. If Kenwood Made an easily obtainable 224 MHz repeater I'd probably have a few already. But I also still enjoy building things from scratch so a 224 MHz repeater using various modules is very practical and still quite fun. cheers, s.
