Practice Test Geeks(CED) Certified Emergency Dispatcher Practice Test
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Radio & Telecommunication Systems Flashcards

7 cards from real CED practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Radio & Telecommunication Systems flashcards as text

  1. A dispatcher hears two units transmitting at the same time, causing an unintelligible noise. This is called:

    Answer: Doubling or kerchunking

    When two units transmit simultaneously on the same frequency, the overlapping signals create noise called 'doubling,' making neither transmission intelligible.

  2. What is the function of the squelch control on a radio?

    Answer: To suppress background noise when no signal is being received

    Squelch mutes the receiver's audio output when signal strength falls below a set threshold, eliminating static noise between transmissions.

  3. During a major incident, the Incident Commander requests a dedicated radio channel for command communications. The dispatcher should:

    Answer: Assign an existing talk group or channel per agency protocol and notify all affected units

    Dispatchers should follow agency protocol to assign a dedicated channel or talk group and notify all units of the change to maintain organized command communications.

  4. What is the primary advantage of P25 (Project 25) digital radio standards in public safety?

    Answer: Standardized interoperability between different manufacturers' equipment

    P25 establishes common technical standards so that public safety radios from different manufacturers can communicate with each other.

  5. A unit transmits 'Signal 9' and then goes silent. If 'Signal 9' means officer needs assistance, the dispatcher should FIRST:

    Answer: Immediately broadcast on the channel for the unit to confirm their status and location

    When a distress signal is received, the dispatcher must immediately broadcast to confirm unit status and location to initiate appropriate response.

  6. In radio communications, what does 'radio dead zone' or 'shadow' refer to?

    Answer: A geographic area where radio signals cannot reliably reach due to terrain or structures

    A dead zone is an area where terrain features, buildings, or other obstacles block or absorb radio signals, preventing reliable coverage.

  7. What does 'DTMF' stand for in the context of telephone and radio systems?

    Answer: Dual-Tone Multi-Frequency

    DTMF (Dual-Tone Multi-Frequency) is the signaling system used by telephone keypads that generates a combination of two audio tones for each digit.