Frequency Allocations: Bands, Emission Types, Band Edges, Sharing, Power Limits, and the ISS

Concept

Back in the lesson on operating procedure, 146.52 MHz showed up as the customary meeting place for calling CQ directly, station to station, without a repeater involved — but that number was never arbitrary, and neither is any other frequency you'll ever key up on. Underneath every band plan and every operating custom sits the actual legal floor: a table in the FCC's own rules stating, plainly, which slices of spectrum a Technician license opens up in the first place. That table draws its lines by wavelength band, not by convenience, so 146.52 MHz falls inside the two-meter band because two meters itself runs from 144 up through 148 megahertz — the custom simply settled on one specific number inside a much wider legal allocation. The same idea holds one band down: 52.525 MHz sits inside the six-meter band, the lowest-frequency VHF allocation a Technician holds, distinct from the HF bands below it and the rest of the VHF and UHF ladder above. On HF itself, though, a Technician's reach is far narrower than on VHF and UHF, and phone — actual voice conversation — is narrower still: the only HF band where a Technician may run phone at all is the upper slice of ten meters, from 28.3 up to 28.5 megahertz. Elsewhere on the HF bands a Technician's license reaches, the privilege stops at Morse code and digital modes; voice conversation has to wait for a higher class of license, or a move up into that top slice of ten meters.

Part 97: 97.301(a), 97.301(e)

Concept

Frequency alone doesn't tell the whole story — what you're allowed to send matters just as much as where you're allowed to send it. CW, plain Morse code, is the one emission the rules permit anywhere a station is otherwise authorized to transmit, on any band, with no separate authorization needed — which is exactly why the narrow sliver from 50.0 up to 50.1 megahertz, at the very foot of the six-meter band, and the matching sliver from 144.0 up to 144.1 megahertz, at the very foot of the two-meter band, are reserved for CW alone: both sit just below where the rules open that band up to phone, data, and everything else, so Morse is the only thing legally authorized right there. Move up out of those two bottom slivers and the door opens wide: digital modes such as FT8 have a legitimate home on all three of the bands a Technician is most likely to reach for them on day to day — ten meters, six meters, and two meters alike, not just one. On ten meters specifically, phone and data don't share the same real estate: the lower part of that allocation is set aside for RTTY and data, FT8 included, while phone waits for that same top slice already anchored above. And once operating anywhere above fifty megahertz at all, SSB voice isn't cornered off into repeater use only, or reserved for some higher license class — every one of those bands carves out at least some stretch of spectrum where SSB phone is authorized outright, right alongside FM.

Part 97: 97.301, 97.305(a), 97.305(c)

Concept

Every one of those allocation tables draws a hard line at its edges, and a well-run station treats that line as something to stay back from, not something to graze. Three separate, perfectly ordinary realities all push the same direction. First, no frequency readout is perfect — there's always some small gap between the number glowing on a rig's display and the frequency actually leaving the antenna, an error built into the hardware itself, and parking a transmit frequency right at the boundary leaves no room to absorb that gap if it happens to push the wrong way. Second, a real transmitted signal is never a single infinitely thin spike — voice and data both spread a little energy to either side of the exact frequency dialed in, and key up with that spread centered right on the edge, and part of it lands on the far side of the line whether the operator meant it to or not. Third, oscillators wander — a rig can warm up over a long transmission, or simply age, and drift a few hertz from where it started, which barely matters in the middle of a wide allocation but matters enormously when there was no margin to begin with. None of these three is the whole explanation by itself; together, they're the entire reason experienced operators build in a comfortable margin and never treat a band edge as just another frequency to use.

Part 97: 97.101(a), 97.301(a-e)

Concept

Not every amateur allocation belongs to the amateur service exclusively. Some of the bands and segments a Technician holds privileges on are shared with other radio services entirely, and the rules label each shared allocation either primary or secondary depending on which service gets first claim there. Where amateur radio holds only secondary status in a segment, the obligation runs in exactly one direction: a licensed amateur transmitting there may well encounter a non-amateur station already operating on that same frequency, and it falls to the amateur station to steer clear of it — not the other way around, and not some shared, negotiated arrangement where both sides compromise equally. That's a sharper standard than ordinary courtesy; it's the actual legal condition attached to operating in a secondary segment, and it's worth knowing which of your own privileges carry that condition before assuming every frequency you're licensed to use is yours free and clear.

Part 97: 97.303

Concept

Power is capped differently depending on where in the spectrum an operator is working, and the two numbers worth anchoring are easy to keep straight once the reason behind each one is clear. Down on the HF bands a Technician holds privileges on — that top slice of ten meters chief among them — the ceiling sits at two hundred watts peak envelope power, a specific, tighter limit written in for exactly those Novice- and Technician-shared HF segments, regardless of what a given station could technically put out. Climb up past thirty megahertz, into the VHF, UHF, and higher territory that makes up the bulk of a Technician's privileges, and — apart from a handful of specific, narrower restrictions tied to particular bands or particular locations — the general ceiling that applies to every amateur station of any license class, on any band, takes over instead: fifteen hundred watts peak envelope power. Nothing about holding that ceiling requires running anywhere near it — the baseline rule everywhere is to use only the power a contact actually needs — but knowing which of the two numbers governs wherever an operator happens to be keeps a Technician from assuming a limit that doesn't actually apply there.

Part 97: 97.313(c)(2), 97.313(b)

Concept

All of this — the tables, the emission types, the band edges, the power ceilings — exists to answer one deceptively simple question: where, exactly, can a station point its antenna and be operating legally? One answer to that question is worth sitting with for a moment, because it reaches further than almost anything else in this unit. The International Space Station carries amateur radio equipment, and its crew — often literally a licensed amateur themselves — gets on the air with hams on the ground over VHF frequencies a Technician already holds full privileges on. Reaching it doesn't call for a General ticket, an Amateur Extra ticket, or any sign-off from NASA or anybody else beyond the license this whole course is building toward: a Technician license, the day it posts to the FCC's system, already carries everything legally needed to attempt that contact. Making it happen in practice takes real timing and real skill — a station in low orbit crosses the sky and drops back below the horizon again within minutes — but the legal permission was never the obstacle standing in the way. It was there from the moment the license itself was granted.

Part 97: 97.301, 97.207(c)