4.6 Required Equipment Tests & On-Air Test Procedure

4.6 Required Equipment Tests & On-Air Test Procedure

Quick Answer: Test by transmitting your call sign followed by the word "test" on the frequency in use. On 2182 kHz or Ch-16, testing must not exceed 10 seconds in any 5-minute period. A compulsory VHF-DSC installation is tested daily at sea. Test NBDP with an ARQ call to a coast station and wait for the answerback exchange. Test Inmarsat-C by sending a brief message to your own terminal. You may test any time except during silent periods.

Official sub-topic 1-C-17 (Equipment Tests) is the operational partner of the logkeeping rules in section 2.4—the tests are what you log. It is also the sub-topic candidates most often lose a point on, because four different systems each have their own test method and the pool asks about them individually.

The on-air voice test procedure

What is the proper procedure for testing a radiotelephone installation?

Transmit the station's call sign, followed by the word "test", on the frequency being used for the test.

Three deliberate components:

Note what is not in the procedure: counting "one two three four five," whistling into the microphone, keying an unmodulated carrier, or asking for a "radio check" from a coast station as a routine matter. Those are habits, not the rule.

The 10-second limit

When testing is conducted on 2182 kHz or Ch-16, testing should not continue for more than 10 seconds in any 5-minute period.

Learn both numbers together—10 seconds in any 5-minute window. These are the shared distress and calling frequencies, and a station sitting on them for even half a minute can mask a genuine MAYDAY. The rule is deliberately tight to make routine testing on a distress frequency almost pointless, which is the intended nudge toward testing on a working frequency instead.

Pool distractors swap the numbers freely: "10 seconds in any minute," "30 seconds in any 5-minute period," "1 minute in any 10-minute period." 10 in 5 is the pair.

When may you test at all?

At any time (except during silent periods) as necessary to assure proper operation.

Two ideas in that answer. First, testing is routine and expected—you do not need permission or a scheduled window, because the whole point of a test is to confirm the gear works before you need it. Second, silent periods are excluded. On 2182 kHz the traditional silent periods run for three minutes from each hour and each half hour, when stations listen for weak distress traffic. Testing through a silent period defeats it.

Contrast this with genuine urgency or distress traffic (section 3.4), which is never blocked by a silent period. The restriction applies to testing, not to real emergencies.

System-by-system test methods

This is the part worth drilling as a table, because each system has exactly one keyed answer:

Why each method is the right one

VHF-DSC — daily. Under GMDSS a compulsory VHF-DSC installation must be tested at least daily while at sea. Daily because DSC is the primary alerting path on a coastal voyage and a silent failure would be invisible until the moment it mattered. Do not confuse this with the monthly EPIRB interval; the pool pairs them precisely to catch that swap.

NBDP — ARQ answerback. Narrow-Band Direct Printing (radiotelex) is tested by placing an ARQ (Automatic Repeat reQuest) call to a coast station and confirming the automatic exchange of answerbacks. The answerback exchange proves the whole chain end to end: your transmitter, the link, the coast station, and your receiver and printer. A one-way "send some text and see" proves far less, which is why the specific answer names ARQ and answerbacks.

Inmarsat-C — message to yourself. The self-addressed message is elegant for the same reason: it exercises transmit, the satellite, the land earth station, the routing, and receive, all without bothering anyone ashore or generating traffic someone must answer. Options suggesting you call the Inmarsat operator, send a test to a coast station, or trigger the distress button are wrong—and the last one is seriously wrong.

Never test with the distress function

It should not need saying, but the pool tests it obliquely in several places: you do not verify a DSC controller by pressing the distress button, and you do not verify an EPIRB by activating it. Both generate real alerts that pull SAR resources. Use the built-in self-test, and if a false alert does go out, cancel it immediately (section 5.2).