• 15Feb
    Categories: 147.080+ VHF, Repeaters Comments Off on 147.080+ Repeater Realigned

    On 2/7/09, Russ, N7SMA & AJ, K6LOR met up to realign the 147.080+ Mastr II VHF repeater that was previously up on Wilderness Ridge. We are happy to report that, after some interesting “tail chasing”, the VHF repeater now sits at a very reasonable .18 uV sensitivity as measured by a calibrated HP spectrum analyzer and is spot on frequency, plus or minus a few hertz, with 26 watts out at the P/A. The remaining desense issues are in three distinct locations that must be resolved:

    • Repeater to Duplexer Interconnection Cables
      • Receiver to Duplexer
      • Transmitter to Isolator
      • Isolator to Duplexer
    • Duplexer to Antenna Cable
    • Antenna

    In order to trace down the desense, the interconnection cables are the first to be replaced as they’re already a mismatch of cabling:

    RG9

    RG214

    Belden 9914

    Belden 9913

    The overall consensus of the repeater building community is that anything other than Heliax-type cable will likely result in some form of leakage, contributing to desense.

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