Dave Gomberg wrote: > I have long considered building my own 2m repeater out of 2 Icom 2100 or > 2200 back to back thru a repeater controller, using a good duplexer and > a Comet or Hustler antenna. Here are my questions: > > 1. Nobody seems to like the Comet or Hustler antennas. Why? I have > no ice here, lots of wind tho. Ruggedness of the amateur grade antennas versus commercial grade. If you are going into a commercial repeater site, you will likely need to have a certified / insured tower crew install the antenna and feedline. If it fails (and the amateur grade antenna is much more likely to fail than commercial grade), the cost to get the tower crew to do it will most likely be way more than the additional initial cost to have used a rugged commercial antenna in the first place. Also, many of the amateur antennas use small capacitors (another weak spot) internally to tune the antenna.
> > 2. Why is a 50w 2m transceiver, derated to 25w and driving a power amp > a bad choice? Or is it OK? Most folks would say you should design the repeater for transmit periods of many, many hours straight. Few amateur transceivers can survive that even at reduced power without forced air cooling over the heat sink. Wide band noise specifications can also be a possible problem with an amateur transmitter. Most commercial sites will require commercial grade equipment. Although not mentioned, the receiver in an amateur transceiver will not have anywhere near the amount of off channel protection that is typically found in a receiver designed for repeater service. > > 3. Any suggestions on how to keep the duplexer cavities affordable? Not me. > > 4. Which repeater controller? Or is that a religious question? Somewhat. You also should state what else may eventually be connected to the system to properly determine how complex of a controller is needed. > > Anything else I should be wary of? Two meters in the bay area is likely to be pretty busy already and difficult to get coordinated. To see how crowded two meters is, visit: http://www.narcc.org/ and look at the list of repeaters already on two meters. You might have a better chance (and cheaper antennas & duplexers) on some of the less popular repeater bands (900 or 1200 comes to mind). > > -- > Dave Gomberg, San Francisco NE5EE gomberg1 at wcf dot com Ed Yoho W6YJ
