PSRA Level 1 Exam common mistakes
PSRA Level 1 Exam · Understand the traps and how to avoid them.
Treating dBm, dBW, and dB as interchangeable when computing link budgets, so a 40 W transmitter is written as '40 dBm' and the resulting receive-level answer is off by roughly 30 dB.
Candidates memorize the decibel formulas as symbols but never anchor them to reference values, and under time pressure they default to whichever unit appeared last in the question stem.
What to do instead
Before every calculation, convert all powers to a single absolute unit (dBm is safest) and keep gains/losses in dB only. Drill the anchors until automatic: 0 dBm = 1 mW, 30 dBm = 1 W, 40 W = 46 dBm, +3 dB doubles, +10 dB is tenfold. Write the unit next to every intermediate number in your scratch work and re-read the stem to confirm which unit the answer requires.
Confusing simplex, half-duplex, full-duplex, and talk-around operation when asked which mode a described field scenario uses, or which repeater configuration is required.
The terms are learned as vocabulary rather than as channel architectures, so candidates cannot map a described workflow (two units on a direct channel, a dispatcher hearing both sides, a unit transmitting and receiving on the same frequency) onto the correct label.
What to do instead
Build a four-row table: simplex (one frequency, one direction at a time), half-duplex (two frequencies via repeater, push-to-talk), full-duplex (simultaneous, separate paths), talk-around/direct (bypasses repeater). For each, list the frequencies used, who hears whom, and the failure symptom if the mode is wrong. Practice by reading scenario stems and naming the mode before looking at the options.
Answering interoperability questions by naming a technology (P25, LTE, a gateway) instead of the governance and planning element the question is actually testing, such as a shared channel plan, a memorandum of understanding, or a common talkgroup naming convention.
Candidates equate 'interoperability' with 'digital radio standard', so they pick the most technical-sounding option even when the stem describes an exercise, a mutual-aid response, or an agreement between agencies.
What to do instead
Separate interoperability into three layers: technical (waveforms, gateways, channel naming), operational (common talkgroups, plain-language protocols, shared response plans), and governance (MOUs, funding, coordination bodies). Read the stem for keywords like 'agreement', 'exercise', 'planning', or 'procedure' and select from the matching layer. When a stem names a standard, ask whether the question is about the standard itself or about how agencies use it.
Predicting coverage from a single free-space path loss figure, ignoring terrain, clutter, antenna height, and the difference between coverage prediction and measured drive-test results.
Free-space loss is the only propagation model most candidates can compute confidently, so they apply it everywhere, including suburban and hilly environments where it badly overestimates range.
What to do instead
Learn to select the model to fit the environment: free-space for clear line of sight, two-ray/plane-earth for flat ground with a reflecting surface, and empirical clutter models for built-up or irregular terrain. Always state assumptions (antenna height above ground, effective radiated power, receiver sensitivity, required margin). Treat any prediction as an estimate and expect drive-test verification; questions contrasting predicted versus measured coverage are testing exactly this discipline.
Mixing up which entity does what in licensing and coordination: assuming the FCC assigns specific frequencies to public safety licensees, or that a coordinator grants the license rather than recommending frequencies.
The workflow (applicant files, coordinator recommends, Commission grants, licensee maintains compliance) is compressed into a vague memory of 'the FCC handles frequencies', so role-assignment questions are answered by guesswork.
What to do instead
Write the pipeline once and memorize it: applicant determines need and eligibility, certified frequency coordinator recommends channels, FCC grants the authorization, licensee operates within its parameters and keeps the license current. Separately memorize which items are license conditions (emission designator, authorized power, antenna height, geographic area) versus operational choices. When a stem asks 'who', answer with the role in the pipeline, not the agency name you associate most strongly with radios.
Diagnosing a reported coverage or audio problem by jumping to a hardware replacement instead of reading the available evidence: RSSI, bit error rate, channel busy statistics, alarm logs, and whether the fault is site-specific or system-wide.
Candidates treat troubleshooting questions as recall of common faults rather than as a diagnostic sequence, and they skip the step of establishing scope and baseline before choosing a cause.
What to do instead
Apply a fixed order: define the symptom precisely (which talkgroup, which sites, which times), check whether it is isolated or widespread, compare against a known-good baseline, then examine the specific metrics that discriminate between candidate causes. For example, high RSSI with high error rate points to interference rather than weak signal; a single-site failure points to backhaul or that site's equipment. State the discriminating measurement before naming the fault.
Treating radio security as equivalent to over-the-air encryption only, so questions about authentication, key management, logging, or insider risk are answered with 'enable AES' regardless of what the stem describes.
Encryption is the most visible control and the easiest to name, so candidates collapse a layered problem into one control and miss the control that the scenario actually calls for.
What to do instead
Organize controls by threat: confidentiality (over-the-air encryption), authenticity and access (subscriber authentication, programming protection), key lifecycle (generation, distribution, storage, revocation, rotation), availability (jamming detection, redundancy), and accountability (audit logs, role-based access to programming tools). For each scenario, ask what the attacker is trying to achieve and which layer stops it. Remember that encryption without key management and authentication leaves known weaknesses.
Describing incident support in generalities ('communicate clearly', 'follow the plan') instead of naming the concrete artifacts: an incident action plan communications unit, a communications unit leader role, assigned talkgroups, a tactical channel naming scheme, and a documented after-action record.
Candidates know the incident command structure loosely and cannot map communications responsibilities onto specific roles and documents, so answers stay abstract and fail the specificity the questions reward.
What to do instead
Memorize the communications-related positions and products: who plans the communications portion of the incident action plan, who assigns channels and maintains the incident radio inventory, and what a written communications plan contains (assigned talkgroups, channel names, contact lists, escalation path). Practice writing a one-page communications plan for a sample event and you will recognize the correct option descriptions.
Assuming a modernization path is automatically better because it is newer, without evaluating migration cost, backward compatibility, coverage parity, and the operational transition period for legacy subscribers.
Marketing framing around new technologies leads candidates to pick the newest-sounding option even when the stem emphasizes budget constraints, existing fleet size, or the need to keep interoperating with neighboring agencies.
What to do instead
Evaluate every modernization option against four explicit criteria: capability gained, compatibility with existing users and partner agencies, cost and schedule of transition, and risk during the coexistence period. Recognize that a well-planned phased migration with dual-mode equipment or gateways is often the correct answer over a wholesale replacement. When a stem lists constraints, treat each constraint as a filter and eliminate options that violate one.
Answering spectrum questions from memory of band names rather than from the actual characteristics: which bands suit which use, why narrowbanding matters, what adjacent-channel and co-channel interference look like, and how spectrum sharing affects public safety.
Band labels are easy to memorize in isolation, but candidates never connect them to propagation behavior, licensing rules, and interference mechanisms, so applied questions expose the gap.
What to do instead
For each major public safety band, record the approximate frequency range, typical propagation and building penetration behavior, typical use, and the main interference concern. Then connect narrowbanding to co-channel spacing and interference potential. Practice explaining, in two sentences each, why a given band would or would not suit a described requirement; that exercise covers most applied spectrum questions.