UPDATE 2/3/2019: The BRAARC Technical department made the climb 110 feet to the 440 repeater site to install a temporary feedline and antenna. Early reports of repeater performance are not hopeful. However, the SWR is much improved over the original antenna and feedline. We look forward to your signal report.
440 Temporary Antenna
440 Temporary Antenna SWR
FSU Cramer Hall
The BRAARC Technical department is busy working on adjusting a set of new duplexers for the 440 Repeater. Good progress is being made on the Decibel Products, Inc. model 532-4001-004 Transceiver Duplexer salvaged from a commercial repeater. Club members enjoyed a tech-corner presentation during the January meeting that reviewed the function and construction of duplexers. As discussed, careful adjustments are necessary to block and pass the appropriate frequencies to allow for proper repeater operation. Highly specialized equipment is used to adjust these characteristics of the duplexer. It appears the duplexer is in fair condition and is able to be adjusted after extensive cleaning.
440 low-pass filter
440 high-pass filter
The band pass and block adjustments are visualized and measured using a spectrum analyzer with a tracking generator. The low and high band pass and block adjustments are made in the same fashion. The manufacturer provides detailed instructions to aid in properly adjusting the duplexer. The club expects to install the duplexer soon.
Happy Hamming
KD8DIB