Rattlesnake 430 Repeater – Technical Specifications

Tower:

  • Elevation:  2408 ft. AMSL

Antenna:

  • Height:  100 ft.
  • HAAT:  906 ft.
  • Type:  Telewave ANT150D6-9 four-element folded dipole
  • Gain:  6dBd
  • SWR:  1.1:1  (est)
  • Azimuth:  265 degrees

Feed Line:

  • 120 ft. of 1-1/4″ hard line

Duplexer:

  • Type:  Four-cavity VHF Duplexer
  • Jumper Type:  RG-214/U

Bandpass Cavity Filter:

  • Model:  MFC 2510-1
  • Insertion Loss:  8dB
  • Frequency:  147.430 MHz

Preamplifier:

  • Model:  Advanced Receiver Research P144VDG
  • Gain:  24dB

Repeater:

  • Model:  Yaesu DR-1X 144 MHz C4FM/FM digital repeater   manual   leaflet
  • Serial:  5G200024
  • Nominal TX Power:  50W
  • Actual TX Power:  28W (May 2020)
  • DC Current:  5.5A drawn from backup battery when transmitting with AC power off (May 2020)

DC Power Supply:

  • Model:  Astron RS-35M
  • Current:  25A continuous, 35A peak
  • Voltage Range:  11-15V adjustable
  • Output Voltage:  Set to max possible level of 14.11 VDC
  • Role:  Backup battery charging through PWRGate PG40S module.

Backup Battery:

  • Make:  Duracell
  • Model:  31DTMAGM
  • Type:  AGM
  • Capacity:  105Ah @ 20-hr rate
  • Group Size:  31
  • Discharge Testing – June 1, 2020:
    • Test Protocol:
      • Initial State of Charge:  100%
      • Battery Temperature:  70 F
      • Discharge Current:  7.5 Amperes
      • Cutoff Voltage:  10.5V  (0% state of charge)
    • Test Apparatus:  West Mountain Radio CBA II Computerized Battery Analyzer
    • Test Results:  Amp Hours    Watt Hours    Minutes

Power Source Selector:

  • Model:  West Mountain Radio PG40S Super PWRgate
  • AGM Jumper:  Installed as required for an AGM battery
  • Maximum Charge Current:  Set to 10 Amperes  (safely below max charging rate for a 105Ah battery)
  • Recommended Power Supply Voltage:  Ideally 14.5V to ensure AGM battery is charged to 100%
  • Actual Power Supply Voltage:  14.11V  (max possible with Astron RS-35M supply)

RF Power Measurements:  (May 2020)

Location Power Source Forward Power (W) Reflected Power (W)
Transmitter Output AC 28 1
Battery 25 1
Duplexer Output AC 23 0
Battery 20 0

Known Issues:

  • Repeater TX Power – The Yaesu DR-1X repeater has a rated power output of 50 watts, but its actual power output is only 28 watts.
  • Repeater Squelch Tail – The repeater’s squelch tail exhibits an unusual “two click” sound which occasionally sounds like two horn blasts.