Simplex Connectivity Test


While many Ham radio operators use VHF and UHF repeaters regularly to communicate, during an emergency these resources may not be available.

The purpose of this test is to work on Simplex communication skills and assess connectivity for an ad-hoc Simplex network.

Setup and Test


  • The NCS will assign each participant a number (this may occur during checkin), write the call sign down in the appropriate row of the Results table.
  • Make sure you have an accurate clock available (computer clock, or wwv)
  • Make sure your radio is programmed for Simplex Operations on the correct frequency
  • Print out a copy of the Simplex Connectivity Form

Test procedure

  1. The NCS will assign:
    1. The simplex frequency for each band
    2. The start time for each band to be tested (recommend hour or half hour)
    3. Based on the number of participants, the NCS will assign a time to switch frequencies
      1. After the band has been tested, the participants will return back to the Primary net control frequency
    4. The NCS will give a time check to synchronize the time for the participants.
    5. When the stations have returned to the Primary Net Frequency The results will be reported:
      1. The NCS will call each station in assigned order.
      2. The station will report readability and strength for each participating stations
        1. Note, if the strength was estimated, the station will report “All strengths are estimated” before reporting the first values.
  2. Typically 3-5 minutes will be allowed to switch frequencies
    1. Switch to the simplex frequency
    2. Turn squelch off (or to minimum setting)
    3. Begin listening at the assigned start time
  3. Each station will transmit for 30 seconds
    1. Each Station should begin their transmission at Test Start Time + ID minutes
      1. For example If the test is scheduled to start at 19:30 Station1 will begin transmitting at 19:31 (19:30 + 1 minute)
      2. If the test is scheduled to start at 13:00, Station 12 will begin transmitting at 13:12 (13:00 + 12 minutes)
    2. Each Transmission will:
      1. Begin with he station call sign repeated 2 times using ITU phonetics
        1. This is Alpha Delta Zero Zulu Mike.
      2. Repeat Grid Square 2 times:
        1. My grid square is Delta Mike Seven Nine Mike Romeo.
      3. Report your radio type and transmission power level
        1. I am using an HT, outdoors at 8 watts with a whip antenna five feet above ground, repeat I am using an HT, outdoors at 8 watts with a whip antenna five feet above ground.
        2. Radio Types: HT, Mobile, Base Station
        3. Antenna Types: Rubber Duck, Whip, Mag Mount, dipole, etc.
      4. Close with call sign and time:
        1. This is Alpha Delta Zero Mike Romeo returning to monitoring at <Time to minute>
    3. The transmission must last at least 30 seconds, but no more than 50 seconds.
    4. Each Station should begin their transmission as close to the top of the minute as possible.
    5. When you are not transmitting, you should listen for the other stations.
      1. Record their readability and signal strength.
  4. When the band has been tested, return to the net frequency
  5. The NCS will call roll and ask for your report for each station.
    1. In the case of multiple band tests, the NCS will give the next start time and direct you to switch to the next band and repeat.

Readability and Strength


  • 0 – nothing heard
  • 1 – carrier detected
  • 2 – required multiple repeats
  • 3 – very noisy, but readable
  • 4 – some background noise
  • 5 – complete quieting

Signal Strength

If you have the capability, record the measured Signal Strength, otherwise

  • 0 – heard nothing
  • 3 – quiet audio
  • 5 – like they were in the room with you.

Simplex Connectivity Test Form