Design Goals for the new Repeater Controller

The SCVRS Technical Comittee had a set of goals to update the equipment and controller for the repeater much of which had been in service for over 20 years.

The goals are:

  • Improve the quality of the signal (remove intermod, make clean) and the system.
  • Solid and flexible primary control.  Primary control can be accomplished in the following ways:
    • Primary line, digital via dialup
    • Primary line, digital via the internet
    • Phone line, dial up via touch tone
    • Over the air, via touch tone
  • Simple wiring.  Standardized on RJ-45 LAN cables.  A few other custom cables were necessary.  All cables are numbered on both ends, and in the middle for easy tracing and reassembly.
  • Software control and flexability, including:
    • Security.
    • Implements club and trustee policies.
    • Phone patch.
    • Reverse patch (used for newsline, special events, and primary control).
    • Linking.
    • Logging of primary commands, by operator and time.
    • Timed events.
    • Usage statistics gathering and presentation (future).
    • Ease of maintenance/upgrades
    • Site data aqusition.(volts, amps, temp, etc).
    • MIC-E Enabling
    • Remote diagnostics of any problems, It is a long drive to the mountian top, even when the roads are passable.
  • Low power for controller/interface.
  • Low transmit power control, if we lose AC Power.
  • Ability to remove DC power from the radios via primary.
  • Positive front panel control.  A front panel Touch Tone mike and associated circuits acts as a receiver. A switch selects the repeater it works with. It also selects the monitor of that repeaters transmit audio.
  • Support up to 6 repeaters.  Three are currently implemented.
  • Future support for MIC-E, for APRS.
  • Modular design of the interface.  Although the RLC-3 controller can directly interface with most radios (with some wiring magic), it cannot do front panel and some of the other interfacing stunts.  The interface box contains:
    • Power regulator, circuit breaker, and filters. Filteed 12v power feeds the RLC-3 controller.
    • Modem, currently not used, replaced by the laptops. Modern modems that can take 12vDC that is not isolated from ground is hard to find.
    • 18 RJ-45 connectors on the back, another 6 on the front. for all interfacing except to the RLC-3 Controller which used DB-9's and a wrap thru DB-25 pair for analog/digital control.
    • A front panel with:
      • Power on LED (from 5V)
      • Circuit breaker (2 amp yet)
      • 6 LED's, one for each repeater
      • A 6 position switch (from a SCSI Address drive box)
      • A volume control, with off switch (disables audio amp and the power to the front panel LED's, to recuce power consumption).
      • A simple audio amplifier driving the speaker.
      • A speaker, formally serving duty in an old PC.
    • A mother board with:
      • Local mike support.
      • A gain amp for local audio.
      • Op-amp for battery current (charge/discharge) monitoring
      • Repeater selection
      • Front panel support circuits
      • Pullups for various control functions
      • Connectors for mating to all interface cards.
      • Connector for mating to power supply control/monitoring
      • Connectors for MIC-E TNC control.
      • Cross connect all signals and and connectors as needed.
      • Power distribution to Interface cards
    • The interface card was designed to be flexable and interface to single repeater. They are on 2.5 inch centers on the botom of the  back panel. Each 2x6 inch interface card has:
      • A DB-9 at one end, that mounts to the back panel. The mounitng nuts also provide cable retention and card retention.  The other end has a plastic block that rests on the bottom of the box.
      • A 20 pin connector, wired to the receive and transmit RJ-45 connectors for the repeater on the back panel. Hey this eats 12 of the RJ-45 connectors.
      • A 16 pin IC socket that mates with a flat cable.  The cable is split, 8 wires are common to all interface cards, the other 8 are unique.  This cable terminates on the motherboard.
      • A shift register, and driver to receive control data from the controller. We use a single-shot to eliminate the data wiggle associated with using the shift register alone. Currently only 6 of the signals are used.  The drivers are open collector, some may include a pullup, and does allow dot-oring if needed.  Uses a 4094, 7416, and 74HC123.
      • An audio switch (4066) that:
        • Selects local mic or receiver audio to the controller.
        • Gates xmit audio to the front panel.
        • Mutes xmit audio for MIC-E
      • Logic and interconnections for the radios and controller Uses a 4011 and 4001.
      • PL encode, decode. and filtering (only done for 220)
  • For older radios, such as our 220 equipment, we chose to interface the RJ-45 wiring to a Motorola pinout standard for transceviers.  This will allow plugging in standard radios as spares with no additioal work.  It also allows two control line for such functions as squelch, PL, or power level controls.  Hey us hams need something to play with.
  • The Virtex can be run, but not controlled, with a single RJ-45.  The audio in/out is transformer coupled in the radio.  The PTT and COR are opto-isolated.  Hint, we put an LED in series with the PTT on the interface card, it lites only if the circuit is conplete and there is PTT.  Cost nothing in current drain, but is a great troublshooting aid.
  • The Virtex control is through a DB-25.  We built a DB-25 to RJ-45 cable for each Virtex.  The Virtex has 3 address lines to select preset channels.  we used two to select PL (encode/decode options). We also used squelch sensitivity and s-meter output. We modified the Virtex to do remote power level control.
  • Y2K Compliant.

Last modified 01/02/2000 ggm