The Current Repeater
Currently, the repeater is a Bridgecom Systems BCR-40U. The duplexer is a Bridgecom Systems BCD-440 mounted inside the repeater chassis. The antenna is a Spectral Isopole 440 mounted in my backyard at about 25 feet. The repeater is located in Los Alamos. For feedline, I am using some of the dreaded double shielded cable. The aluminum foil rubbing against the silver plated copper braid is supposed to cause noise. I have not noticed any problems yet.
Update 24 June 2018
For some reason, I was never able to get around to retuning the Hamtronics transmitter and repeater. Also, I was never able to get a decent 440 duplexer off of eBay. So, I gave up and bought a Bridgecome 440 repeater with an internal duplexer. Talk about turn-key. I plugged it all in and it worked.
Update 16 November 2010
Would you believe that I got the crystal pair reversed. I now have the correct transmitter crystal and the receiver is synthesized. I will have to install the crystal and retune both the transmitter and receiver.Beware of ebay duplexers. I am currently running a 4 cavity mobile duplexer which is not working out. The desense is terrible. I have my second 6 cavity mobile duplexer from ebay that I hope works out. The first one had a bunch of damage inside one of the cavities.
Update 26 April 2006
The transmitter crystal came and I installed it. Now, the transmitter is running and I believe that it is on frequency. I have also tuned the duplexer to the best of my ability and equipment. The receiver is semi-tuned. It turns out that I didn't have all of the equipment that I needed to completely align the receiver. As a result, I have a used, ebay signal generator coming. With any luck, I should have the machine completely tuned in a couple of weeks.
Update 1 April 2006
This is the day that I was going to have the repeater up and operating. My attention was consumed by the 220 machine's amplifier. Today, I started wiring the receiver and transmitter to the power plug and DB-9 connector.I am still waiting on a crystal to put the transmitter on the proper frequency. I still need to learn how to tune the receiver front end and the duplexer.
Notes
The repeater is located at my house in DM65uv.The repeater is made up of Hamtronics components with the exception of the controller, duplexer and antenna.
The receiver is a Hamtronics R304-6 UHF receiver that I converted to a R304-4.
The exciter is a Hamtronics TA451 UHF exciter. I am running the crystal oven to maintain frequency stability.
The duplexer is one of those generic 6 cavity mobile duplexers. With a transmitter output of 2 watts, this should provide adequate separation.
The antenna is triband antenna mounted at the peak of my house.
While building this repeater, great care was taken to double shield everything. The receiver and exciter are all contained within their respective tin boxes. All non RF connections go through feedthrough capacitors to exit the tin box. The tin boxes are mounted in a home made chassis partitioned to separate sections for receiver and transmitter components. Again, the non RF connections are run through another feedthrough capacitor as they exit the aluminum enclosure.
The contoller is mounted in an aluminum box that is separate from the repeater chassis. With this arrangment, I hope to be able to experiment with various controllers without tearing anything apart.