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The 927.4875 repeater went online in the early afternoon on Sunday May 23, 2004. Lots of planning, coordination, and hard work went into preparing all the components and actually putting them to work.
The receiver is a Motorola Maxtrac 800 trunking radio. Dave (N1OFJ) made the necessary hardware and software changes to the radio, bringing it up to 902.4875. Sensitivity is an awesome .17 uV!! Inline with this receiver is a pre selector circuit consisting of an ARR tuned Preamplifier and a Decibel Products Band Pass/Reject filter.
The transmitter for this system is now a hybrid of sorts. Dave (N1OFJ) and Bob (WA1MIK) recently completed some customizations that greatly improved the audio quality. The transmitter now consists of a Motorola Maxtrac doing all the audio processing and is fed into the Nucleus II exciter module. The Maxtrac limits and filters the audio, applies pre-emphasis, and adds the PL. In addition to better audio in general, this provides a true reverse-burst squelch tail elimination. These customizations were pioneered by Bob and have been published on the Repeater Builder website.
The rest of the Nuke II is as it was before, a 300-watt continuous duty paging transmitter pushing 250 watts of RF! There are two tuned Wacom bandpass filters on the transmitter to accomplish “spectral purity” (those are Dave’s own words!).
Of course, there has to be a controller. In this case, it is a Micro Computer Concepts RC-100 repeater controller. Timing, CW ID, and all other aspects of control are accomplished with this controller.
The antenna is a Decibel DB806D-Y. This antenna is actually two antennas in one large radome. The transmit antenna is in the top section and the receive antenna is in the lower section. There are two runs of 7/8 Andrew Heliax back to the radio room.
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