220 Repeater Information

     The KD8BIW Repeater is sponsored by Gregg KA8GKT, Rob KD8FTR, and Mike KD8IYX.  The repeater started it's life as a Spectrum Communications SCR-1000 back in 1979.  When we acquired it, it was in bad health.  The receiver was poor, and the old exciter and amp had seen better days as well.  The repeater was gutted, removing everything except the new controller, which is a Micro Computer Concepts RC-100 that was installed in the mid 1990's.  We replaced the 30 year old equipment with new Hamtronics receiver and exciter boards.  These are synthesized, state-of-the-art units that require no crystals, and simply work great!  We rebuilt the original amplifier and re-installed it.  We purchased a CSI-32 community tone panel from Dave Firis- AL7OP, to use as a CTCSS decoder/encoder.  Everything was put together, tuned, and placed on the air.  The antenna being used is a Hustler G7-220 with 240ft of 7/8 hardline feeding it.  The old amp worked, put it was spurious, and was only making 10 watts, it originally made 30, so it was time to replace it.  We then acquired a Uniden ARX-1250 commercial 220 amplifier and power supply from Scott Ferko-AI8S.  If you are familiar with these, you know that they are built like tanks!  The amp runs on 28 volts and is capable of 125 watts continuous duty on ACSB (side band).  We tested it and was getting 100+ watts with 2.5 watts drive on FM, which suited us just fine.  A used GE rack mount cabinet was donated by Radio Communications of Ohio in Marion to mount all of the equipment.  The new amp and repeater were moved into the new cabinet on 11/15/09 and placed in service.  The exciter was tuned to allow the amp to put 80 watts out, which gives us ~60 watts out of the duplexers.  With the new higher power amp in line, the old Wacom WP-652 cavities did not provide enough isolation to prevent some pretty serious desense.  Two additional Wacom WP-652 cavities were donated by Ken Snare- KC8BPE.  With an additional cavitiy on transmit and receive, we now have plenty of isolation to keep it all working as it should.  So far, everything seems to be working great.  The next upgrade for the repeater is a better antenna (hopefully a DB-224-JJ) that will be top-mounted, and better feedline, 1.25" hardline!  Please let us know how it is working for you!  Send signal reports to KD8BIW@hotmail.com and we hope you enjoy using the repeater!