Amateur Radio technician pool topics

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This is a list of topics we want to cover in an introductory amateur radio lecture / crash course.

The intent is to

  • Grab interest in amateur radio for those who don't know what it is and keep it fun
  • Cover topics in questions on the technician exam
  • Surround this material with supporting material that will make the critical parts more memorable
  • Leave new hams with the foundation of knowledge (beyond the exam) needed to become good technician operators
  • give a taste of material on the general and extra exams where it is closely enough related to be easy to cover

See also: Amateur radio glossary

This is a summary of things in the tecnician question pool released 2022, we hope to add differences with the 2026 pool soon.


Questions needing attention[edit | edit source]

This is based on the 2022-2026 technician question pool. (Will add markers for future differences later.)

  • Problematic questions: T2C09(dangerous) T3A08(ambiguous) T3A07(conflict) T4A11(obsolete?) T1D03(mismatch97) T8C09(2ans) T8D12(ambiguous)
  • Null questions: T1A11 T1E01(?) T1E02(?) T1E06 T2C01 T3A12
  • questions not covered: T4B02 T7B08 T7B09 T7B11
  • New questions not addressed for 2026 pool: T1A06 T1A10 T2C12 T3B12 T7B04 T7B11 T7D05
  • Removed 2022 questions: T1A04 T1A06 T1A10 T1A11 T1B05 T1C06 T1C07 T1D07 T1E09 T1E11 T2A12 T2B12 T2C08 T4B04 T4B07 T5A04 T5C06 T6A09 T6B11 T7A11 T7B04 T7B11 T7C11 T8B10 T9A08 T9A09 T9B01
    • Note: some of these were replaced rather than deleted.
    • verify material against the new pool before removing anything

Topics in the question pool[edit | edit source]

misc[edit | edit source]

  • Purpose: Advancing skills in the technical and communication phases of the radio art (97.1)
  • Govt. Agencies that regulate us: FCC (97.1), FAA
  • Agencies that we cooperate with: FEMA, NWS(skywarn)
  • services within amateur radio: (97.3(a)(38), 97.407)
    • ARES(ngo under ARRL), interfaces with local govt for emcomms
    • RACES (Legal entity): civil defence communications activated during national emergency
  • willful interference (QRM vs QRN)
  • talking to ISS (97.301, 97.207(c)

Identification[edit | edit source]

  • Must ID (at least) every 10 minutes and on final transmission (Qx2)
    • exceptions: control model craft (97.119(a))
    • tactical calls (or call signs) can be used at the beginning of transmission
  • Phone mode must use english language to ID
    • use of phonetic alphabet is encouraged (97.119(b)(2))
    • CW can also be used
  • Call sign length based on license level 1 or 2 by 3 for tech
  • call sign may have a selected suffix using ( / slant slash stroke) followed by a valid US letter (97.119(c)) and not conflict with other indicators or prefixes

Licensing[edit | edit source]

  • Each operator may have exactly one primary station license (97.5(b)(1)])
  • A trustee (like Steve) may also hold one club license (like our club's K4UCF) which is not a primary operating license if the club has at least 4 members
  • The proof of license is its existence in the FCC ULS database (97.7), call sign is effective as soon as it shows up (97.5a)
  • currently issued license classes: Technician, General, Extra
  • vanity call system, including US Amateur Radio Call Signs
  • FCC must be able to contact you by snail mail e-mail (97.23) (Qx2) (2026T1A04)
  • renew every 10 years
  • renew within 2 years after expiration or you'll lose the call sign
  • renew no sooner than 90 days before expiration or it will be rejected (2026T1C07)

Station records[edit | edit source]

  • (*)Station should log when the control operator is not the station licensee (97.103(a)}
  • station records should include antenna gain when not a dipole, possibly as manufacturer specs
  • (*)Records must be made available to FCC for inspection on demand (97.103(c))
  • original information transmitted as spread spectrum must be kept in station records

Frequencies and band plans[edit | edit source]

  • technician is authorized for frequencies above 50MHz
  • technician is authorized for pieces of 10m SSB phone and data for technician, max PEP 200w
  • 6m (band edges)
    • magic band and why its called that
    • 6m can propagate via modes common to both VHF and HF including sporatic E, skywave (during sun spots), aurora, ducting, meteor scatter, ground wave, and several of those are unpredictable
  • 2m (band edges)
    • 219-220MHz: fixed digital forwarding only
  • 50.0 - 50.1, 144.0-144.1 CW only
  • primary and secondary allocations
  • interaction of band edges, signal bandwidth, calibration, and drift
  • VHF+ band use: CW, SSB, FM, mostly max 1500W PEP
  • Calling frequencies: FM/146.520

Signals emissions and modes[edit | edit source]

  • single side band (SSB) is a form of amplitude modulation (AM) but uses half the bandwidth
  • packet radio on VHF commonly uses FM.
  • PM (phase modulation) is strongly related to FM
  • FM is typically used on VHF and UHF for local voice contacts especially on repeaters
  • even on UHF/VHF, horizontally polarized SSB is better for weak signal long distance contacts
  • ranked bandwidths (small to large) CW (150-400Hz), SSB voice (2.8-3kHz) = SSTV, AM voice (6khz), FM voice (7khz?-14khz), ATV/AM tv fast scan (6MHz)
  • reducing receive bandwidth can reduce noise (T4B08)
  • USB is used for 10m band
  • AM signals combine and can be distinguished, FM signals interfere and cause buzzing (double) (strongest signal wins)

Repeater operation[edit | edit source]

  • originating station is responsible
  • 2m offset is commonly +/- 600 kHz
  • 70cm offset is commonly +/- 5MHz
  • call someone or respond to someone with TheirCall YourCall
  • "reverse" function on radio swaps repeater transmit/receive freqs
  • subaudible tone (CTCSS) or DCS code
  • DTMF
  • linked repeaters
  • FM overmodulation distortion from clipping
  • SSB overmodulation distortion from ALC
  • DMR talk groups and Code plug
  • DMR color code for access
  • IRLP, echolink uses DTMF to access other nodes using Voice over IP (internet linking)
  • DMR/D-STAR hotspot

Protocol and politeness[edit | edit source]

  • listen / is this frequency in use / CQ CQ
  • negotiate use of frequency if there is a conflict
  • net control: Call the net to order and direct communications between stations checking in
  • spell using the standard phonetic alphabet when clarity is needed
  • "traffic" radiogram message
    • NTS system to accurately transmit messages by voice
    • preamble has metadata to track and prioritize the message
    • includes a "check" that counts word and symbol groups


Restrictions[edit | edit source]

These are prohibited:

  • commercial use
  • broadcasting
    • multiple exceptions to one way comms that are not considered broadcasting
    • can support broadcasting / news gathering directly related to life safety and property protection
  • countries can notify the ITU they don't want hams communicating... (97.111(a)(1))
  • encoding to obscure meaning is prohibited except telecommand to space stations or radio control craft (97.211(b), 97.215(b), 97.113(a)(4))
  • music except ... (97.113(a)(4), 97.113(c))
  • transmission for profit prohibited except...
    • trader's net
    • classroom instruction
  • indecent or obscene language

Third party traffic[edit | edit source]

  • licensed and responsible control operator required
  • foreign stations only allowed when US has a third party agreement ([97.115(a)(2))

Boats and planes[edit | edit source]

  • boat registered in the US and in international waters with permission of the boat's master
  • plane: must get permission from pilot (Pilot must follow FAA rules)

Satellites[edit | edit source]

  • sat telemetry typically sends beacons that include health and status of the sat
  • using excess power blocks other users from using the sat
  • sat tracking programs show
    • maps showing sat position
    • time, azmuth, elevation of the start, max altitude, and end of pass
    • sat frequency including doppler shift
  • Sats can use modes SSB FM CW or other data modes
  • sat modes: UV -> uhf/vhf uplink/downlink
  • spin fading from a tumbling sat with linear antennas being received with linear antennas
  • LEO -> low earth orbit
  • ideal power when the sat beacon is the same signal strength as your downlink repeat

Q codes and prosigns[edit | edit source]

prosigns / procedural signals

CQ
calling any station
TheirCall monitoring
listening and ready to talk
QRM / QRN
man made and natural noise
QSY
changing frequency

Propagation and wave properties[edit | edit source]

  • (VHF) multipath propagation and fresnel zones / picket fencing (Qx2)
  • (UHF) absorption by vegetation
  • (VHF/UHF) horizontal polarization for long distance CW and SSB
  • (VHF/UHF) penalty for (linear) cross polarization
  • Polarization is described by the orientation of the eletric field (2026T9A03)
  • reflections off of buildings and obstructions
  • precipitation attenuates microwave frequencies
  • ground wave
    • refraction of UHF/VHF more than visual
  • ionosphere / skywave propagation
    • HF(regularly) VHF(rarely) UHF(almost never) (Qx3)
    • faraday rotation makes HF elliptically polarized
    • different bands during different times of the day (Qx1) and sunspot cycle (Qx1)
      • 20-40 reflected/refracted during the day
      • 6m, 10m helped during high solar flux
    • Regions: F reflects, D absorbs
  • Electric and magnetic fields are perpendicular in a EM wave (Qx2)
  • Polarization refers to the electric field orientation
  • speed of light in free space
  • wavelength = c / frequency ; meters = 300 / MHz ; c=3e8 m/s (Qx3)
  • bands identified by wavelength or frequency
  • HF=3MHz-30Mhz ; VHF=30MHz-300MHz ; UHF=300MHz-3Ghz
  • auroral backscatter
    • CME!
    • doppler shift and also irregular
    • vhf too!
  • Sporatic E propagation
    • (probably enhanced by meteor showers; seasonal)
    • VHF (2m-10m) over the horizon
  • Knife edge propagation
    • refraction over buildings and mountains
  • Tropospheric ducting (Qx2)
    • weather inversion
    • uhf/vhf > 300mi is possible
  • Meteor scatter
    • mostly 6m

Operational and technical[edit | edit source]

  • power = volts * amps
  • but also radios can be <50% efficient
  • 13.8v is common
  • SWR meters have a max power and valid frequency range
  • I2R losses minimized by short thick wires; losses result in voltage drop
  • digital operations audio hookup, PTT (control?) (Qx3)
  • Digital modes include packet radio, IEEE 802.11(WiFi), FT8, FT4, APRS, Winlink
  • Bonding ground with flat copper strap is preferred (why?)
  • batteries: Ah (time)
  • hot spot for internet + digital modes
  • station setup: radio -> amp/tuner -> SWR meter -> feedline -> (tuner/LNA) -> antenna
  • overmodulation issues
  • front end overload issues, including consumer equipment
  • splattering, spurious emissions, and harmonics
  • effects of being off frequency (FM, SSB)
  • common mode current and chokes (air balun, ferrite core; rf burns, distorted audio)
  • filters for consumer equipment
  • band pass and band reject filters for neighbors and rejecting broadcast
  • transmission line / feed line
    • coax ; weather failure; UV resistance, easier to install (2022 T9B03), higher loss at higher frequencies or higher SWR
    • water intrusion increases loss in coax
    • parallel line: lower loss, more tolerance to high swr, sensitive to surrounding conductive objects including the ground
    • coax ranked by loss highest to lowest: RG-58, RG-213, RG-8, hardline
    • dielectric material in coax causes loss; replacing it with air reduces loss at the cost of increased chance of water intrusion;
    • rank coax loss highest to lowest: solid dielectric, foam dielectric, air core, pressurized dry air
  • connect volt meter in parallel across a component to measure voltage; connect an ampmeter in series with the component to measure current
  • applying voltage to an ohm meter or a multimeter in ohm mode can damage it; check for voltage first, make sure the circuit is not powered
  • acid core solder should only be used for plumbing; residual acid causes instant corrosion when a current is applied
  • a cold solder joint may appear rough and lumpy and is not well attached to both contacts
  • an ohm meter connected to a discharged capacitor will show a short at first but resistance will appear to increase as the cap is charged by the meter
  • gain
    amplifier gain
    ratio of input to output, represents power added
    antenna gain
    the increase in signal strength in a specified direction compared to a reference antenna (dBi=isotropic, dBd=dipole), usually measured in decibels; represents power concentrated; antenna gain, directivity, and radiation pattern are directly related

Antennas[edit | edit source]

  • Beam antenna
  • loaded antenna uses inductors to shorten antenna
  • horizontal polarized antenna
  • shortened HT whip antennas (compromise antenna)
  • shortening a dipole increases resonant frequency
  • antennas ranked by gain: isotropic, 1/4 wave monopole whip or 1/2 wave j-pole, 5/8 wave whip, yagi
  • using a HT whip in a car has reduced effectiveness due to being shielded by the car body
  • 1/4 wavelength at 146MHz is about 19" (typical full size HT whip)
  • 1/2 wavelength 6m dipole is about 112"

Safety[edit | edit source]

  • batteries
    • shorting large batteries is dangerous (2022 T0A01) possibly causing fire, burns, or explosions
    • charging or discharging a battery too fast can cause it to overheat and/or out gas (lithium: thermal run away; lead: hydrogen, electrolyte loss)
  • current through the body
    • may cause involuntary muscle contractions
    • may cause burns
    • may disrupt electrical functions including the heart
  • US 3wire 120v cable: black=hot green=ground white=
  • fuses and circuit breakers can help prevent overloads; replacing a small fuse with a larger fuse could defeat this and cause a fire
  • improve electrical safety by guarding against shock by
    • using 3 wire cords and plugs
    • connect everything to a common ground; star net
    • use mechanical interlocks on high voltage circuits
    • install circuit breakers in series on the hot conductor only (GFCI?)
  • grounding and lightning arrestors
    • Lightning arrestors should be installed and grounded where the feedline enters the building so that lightning doesn't travel into the building and catch it on fire
    • ground rods should be bonded together with heavy wire (6 gauge or larger?) or strap
    • grounds should be short and direct, star network, not in series
    • sharp bends should be avoided
    • follow local electrical codes
  • power supplies have capacitors that may take time to drain after turning it off
  • high voltage requires special meter leads to prevent arcing, use correctly rated equipment for the voltage
  • tower climbing
    • training
    • safety tie offs at all times
    • approved climbing harness
    • always have a helper / spotter / observer
    • do not climb crank up towers unless retracted or saftey locking mechanism installed
  • towers and antennas
    • Antennas and towers should stay clear of power lines and should not be able to fall on them (10ft recommended) (2022T0B06)
    • use saftey wire on turnbuckles so they don't turn with vibration
    • don't put antennas on utility poles (too close to power lines)
  • RF exposure
    • Radio is non-ionizing radiation; UV and higher are ionizing
      • ionizing radiation causes cell and DNA damage
      • non-ionizing only causes heat on absorption
    • VHF (50MHz, 146MHz) is more dangerous and has lower max exposure limits due to greater body absorption efficiency
    • exposure limits are linear with duty cycle
    • exposure calculator must take into account: frequency, distance, power, duty cycle, radiation pattern
    • exposure compliance can be done via calculations based on OET 65, computer modeling, or field strength measurements
    • duty cycle -> average , percentage of time transmitting
    • station licensee is responsible for RF exposure compliance

Terms[edit | edit source]

(see glossary for full definitions)

Supplemental topics[edit | edit source]

  • satellites
  • paid exceptions: 97.113(a)(3)
    1. emergency disaster work and practice
    2. trader's net
    3. teacher at an educational institution using an amateur station for teaching
    4. club station that operates at least 40 hours a week on at least 6 MF+HF bands ... schedule published 30 days in advance ... bulletins and telegraphy practice (W1AW)
  • history
    • pre-1910: spark gap
    • 1910 regulation: commercial use, Titanic
    • WW2
    • FCC/ARRL vs ITU / IARU
    • Hiram Percy Maxim
    • W1AW
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