T2B · 14 pool questions

Repeaters, Simplex, Access Tones & DMR

FM repeater and simplex practice, reverse splits, access tones, DMR operation, resolving operating problems, and Q signals.

Practical takeaway

FM repeater and simplex practice, reverse splits, access tones, DMR operation, resolving operating problems, and Q signals.

Technician exam focus

This group contains 14 questions in the current pool. The teaching below keeps the important tested terms visible while explaining what they mean in normal Amateur Radio use.

1. Repeater versus simplex

Simplex means both stations transmit and receive on the same frequency. A repeater uses separate input and output frequencies. The reverse function on a VHF/UHF transceiver lets you listen on the repeater’s input frequency, which can tell you whether another station is close enough for direct contact.

2. Getting into a repeater

Many repeaters require an access signal. CTCSS is a subaudible tone sent with your voice; DCS uses a digital squelch code. DTMF is the familiar dual-tone “Touch-Tone” signaling used to control some repeater or linking functions. If you hear a repeater but cannot bring it up, check the transmit offset, CTCSS tone, and DCS setting.

3. Digital repeaters have configuration too

A DMR code plug is configuration data loaded into the radio so it knows frequencies, color codes, time slots, talkgroups, zones, and related settings. A talkgroup routes a conversation to a selected group of DMR users rather than simply putting every user on one audio channel.

4. Useful shorthand

Q signals are short operating codes. You should recognize common ones in context: QRM refers to interference from other stations, QRN to natural/static noise, and QSY to changing frequency. They are handy shorthand, but plain language is perfectly acceptable on voice.

T2B checklist

  • Simplex: transmit and receive on the same frequency.
  • The radio’s reverse function listens on a repeater input.
  • CTCSS = subaudible access tone; DCS = digital squelch code; DTMF = dual-tone signaling.
  • If a repeater hears everyone but not you, check offset, tone, and code settings.
  • A DMR code plug contains the radio’s configuration data.
  • QRM is man-made/station interference; QRN is natural noise; QSY means change frequency.
Quiz Me on T2B

Exam scope: NCVEC 2026–2030 Technician Class (Element 2), effective July 1, 2026 through June 30, 2030, with February 19, 2026 errata. The current NCVEC pool is the exam authority; explanatory prose here is SPARKA teaching material. NCVEC pool