T1B: Frequency Allocations and Emission Modes

Knowing which frequencies you are authorized to use — and what modes are permitted on each — is fundamental to operating legally. Transmitting on a frequency you are not authorized to use, or using a prohibited emission type, is a rule violation regardless of intent.

T1B covers the specific frequency privileges available to Technician class operators, how to identify which band a given frequency belongs to, what emission modes are restricted to certain segments, the rules governing secondary spectrum allocations, why you should avoid transmitting at the edge of a band, the power limits that apply to Technician operators, and who is eligible to make contact with the International Space Station.

Technician HF Phone Privileges

On the HF bands — those below 30 MHz — Technician class operators have very limited phone privileges. Phone operation is authorized only in the 10 meter band, and only within the segment from 28.300 MHz to 28.500 MHz. No other HF band offers phone privileges to Technician licensees. Technicians do have CW and some digital privileges in other HF segments, but the phone segment is exclusively in the 10 meter range listed above.

Identifying Amateur Bands by Frequency

Amateur bands are commonly referred to by their approximate wavelength in meters. Knowing which frequencies fall in which band is a practical skill the exam tests directly.

For the exam: 52.525 MHz is in the 6 meter band. 146.52 MHz is in the 2 meter band. These two specific frequencies are tested because they are the most widely used calling frequencies in each band.

CW-Only Segments

Certain portions of VHF amateur bands are reserved exclusively for CW (Morse code) operation. Phone, digital, and other emission modes are not permitted in these segments. The two segments tested in T1B are:

• 50.0 to 50.1 MHz — the bottom 100 kHz of the 6 meter band
• 144.0 to 144.1 MHz — the bottom 100 kHz of the 2 meter band

These CW-only segments exist at the low end of each band to preserve spectrum for weak signal CW operation, which is particularly useful for long-distance propagation experiments where other modes would not be viable.

Special Segment Restrictions

The 219 to 220 MHz segment of the 1.25 meter band has a unique restriction: it may only be used for fixed digital message forwarding systems. No other use — not spread spectrum, not fast-scan television, not emergency traffic — is permitted in this narrow 1 MHz segment. This restriction exists because the segment is shared with other radio services and fixed digital forwarding is its only authorized amateur use.

Secondary Spectrum Allocations

Not all amateur frequency allocations give amateur operators equal priority. In some bands or band segments, the Amateur Radio Service holds secondary status, meaning another radio service is the primary user. When operating in a segment where amateurs are secondary, US operators must be prepared to encounter non-amateur stations operating there legally and must avoid causing interference to them. Secondary users may not claim protection from primary users, and they must yield whenever a primary user is present. This is a spectrum-sharing obligation, not a privilege restriction — amateurs can still use those frequencies, but must do so carefully.

Band Edge Precautions

Setting your transmit frequency exactly at the edge of a band or sub-band is poor practice for three compounding reasons, and all three of them are correct:

• Calibration error — transmitter frequency displays are not perfectly accurate, so what reads as 28.300 MHz might actually be 28.295 MHz or 28.305 MHz
• Sideband extension — phone and digital emissions have sidebands that extend above and below the carrier frequency, so a carrier placed exactly at the edge can push signal energy outside the authorized band
• Frequency drift — transmitters can drift slightly during operation due to temperature changes, potentially moving the signal out of band

All three reasons combine to make transmitting at the exact band edge inadvisable. The correct answer on the exam is that all of these choices are correct.

SSB Phone Above 50 MHz

Single sideband (SSB) phone is not restricted to HF. Technician class operators may use SSB phone in at least some segment of every amateur band above 50 MHz. This makes SSB a viable option for weak-signal VHF and UHF contacts, particularly for contesting and long-distance propagation work where its efficiency advantage over FM is significant.

Contacting the International Space Station

Amateur contacts with the International Space Station are made on VHF bands. Any amateur holding a Technician class or higher license may contact the ISS on VHF bands — this is not restricted to General or Extra class licensees, and no special NASA approval is required beyond holding a valid Technician or higher license. The ISS crew members who hold amateur licenses often participate in scheduled contacts with schools and amateur groups, and these operations fall within standard Part 97 amateur radio privileges.

Power Limits for Technician Operators

Technician class operators are subject to different power limits depending on which portion of the spectrum they are operating in:

• HF band segments — the maximum peak envelope power (PEP) output is 200 watts. This applies to the Technician's authorized HF sub-bands.
• Frequencies above 30 MHz — the maximum PEP is 1500 watts, subject to some specific restrictions that apply in certain segments. This is the same general limit that applies to General and Amateur Extra class operators on most bands.

Peak envelope power (PEP) is the average power supplied to the antenna transmission line during one complete RF cycle at the peak of the modulation envelope. It is the standard power measurement used for SSB and other voice modes.

T1B Practice Questions