Do CW Operators Use Maidenhead Grid Locators?

If you operate FT8, amateur satellites, or VHF contests, you have probably seen codes such as:

FN31, EM48, JO20DB, or IN55CC

These codes are not callsigns or special Morse abbreviations. They are Maidenhead Grid Locators, also commonly called grid squares, QTH locators, or IARU locators.

But are Maidenhead grid locators also used in traditional CW contacts?

The answer is:

Yes, Maidenhead locators can be sent in CW, but whether you need to send one depends on the band, activity, and contest rules—not on the CW mode itself.

What Is a Maidenhead Grid Locator?

The Maidenhead Locator System is an alphanumeric system used by radio amateurs to describe station locations without transmitting a long latitude and longitude.

A locator may look like:

• FN31
• FN31PR
• JO20DB
• IN55CC

According to the IARU Region 1 VHF Handbook, the worldwide locator system was originally defined in 1980. The initial specification used six characters, with a shortened four-character option intended for HF use. Longer locators can be used when greater accuracy is needed, particularly for microwave activity.

Common locator lengths include:

Format	Example	Typical Use
4 characters	FN31	General area identification and some contest exchanges
6 characters	FN31PR	VHF/UHF, portable operation, satellites, and contests
8 characters	FN31PR12	Higher-precision location reporting

At mid-latitudes, a four-character locator identifies an area with a positional accuracy of roughly 80 kilometres, while a six-character locator narrows the location to approximately 3 kilometres.

A grid locator therefore provides useful geographic information without normally revealing an exact street address.

Is a Grid Locator Required in a Normal HF CW QSO?

Usually, no.

A traditional conversational HF CW contact often includes:

• Callsign
• RST report
• Operator name
• City or general QTH
• Transmitter power
• Antenna
• Weather
• QSL information

For example:

UR RST 579 579 NAME TOM TOM QTH LONDON LONDON

For this type of everyday CW QSO, a town, city, or region is normally sufficient. There is no universal rule requiring every HF CW operator to send a Maidenhead grid.

If the other operator does not ask for your grid and the activity rules do not require it, you may leave it out.

However, the original locator specification included a four-character format specifically suitable for HF use. A short grid can be useful when signals are weak, when language differences make place names difficult to copy, or when operators want to exchange location information with fewer characters.

When Are Maidenhead Locators Commonly Used in CW?

1. VHF, UHF, and Microwave CW Contacts

On VHF and higher frequencies, the station’s geographic position is often more useful than the name of the nearest city.

The IARU operating guide states that exchanging a QTH locator is customary during CW contacts on VHF and above. It allows an operator to estimate the direction and distance to the other station quickly. (IARU R1)

Location is particularly important when working with:

• Directional antennas
• Tropospheric propagation
• Terrain-sensitive paths
• Aircraft scatter
• Meteor scatter
• Auroral propagation
• Earth–Moon–Earth communication
• Microwave links

In these situations, knowing the other station’s grid may be much more useful than knowing only the country or city.

2. VHF and UHF CW Contests

Many VHF, UHF, and microwave contests require a grid locator as part of the official exchange.

For example, IARU Region 1 contest rules specify that CW, SSB, or FM contacts may include an RST report, a serial number, and the complete six-character QTH locator.

A typical exchange may look like:

599 003 JO20DB

In this example:

• 599 is the RST report
• 003 is the contact serial number
• JO20DB is the six-character Maidenhead locator

Some contest scores are based on the distance between stations and the number of different locator squares worked.

Rules vary between events. Some require four-character grids, while others require six characters or additional information. Always check the official rules before operating.

3. Amateur Satellites, EME, and Weak-Signal Communication

Grid locators are also widely used in:

• Amateur satellite contacts
• EME, or moonbounce
• Meteor scatter
• Aircraft scatter
• Microwave operation
• VHF/UHF weak-signal work

The IARU operating guide lists satellite, EME, meteor scatter, and auroral communication among the specialised activities commonly found on VHF and higher bands.

The ARRL International EME Contest, for example, requires stations to exchange four-character Maidenhead grid locators. Each unique grid can also count as a score multiplier. (美国业余无线电联盟)

This applies regardless of whether the contact is completed using CW, voice, or another permitted mode.

4. Portable, Mobile, and Rover Operation

A fixed home station will usually remain in the same locator. A portable or mobile operator may cross into a different grid during the same trip.

Grid information is therefore especially useful for:

• Portable QRP operation
• Field stations
• Mobile CW
• Rover contests
• Hilltop operation
• Grid-expedition activity
• Travel and holiday operation

When operating away from home, use the locator of the actual transmitting location—not the locator stored for your home station.

This matters for contest scoring, distance calculations, QSL confirmations, and station-location records.

Should You Send a Four- or Six-Character Locator?

The correct length depends on the activity.

Use a Four-Character Locator When:

• Only a broad geographic area is needed
• You are making a general HF contact
• The contest rules require four characters
• Signals are extremely weak and the exchange must remain short
• The other operator asks only for your grid square

Example:

QTH FN31

Use a Six-Character Locator When:

• Operating on VHF, UHF, or microwave bands
• Working amateur satellites or EME
• Operating portable or as a rover
• More accurate distance calculation is needed
• The contest rules require six characters

Example:

QTH FN31PR

The six-character locator is now the most common full-length format and provides a practical balance between transmission length and geographic precision.

How Can You Send a Grid Locator in CW?

During a casual CW QSO, the grid can be included with your QTH information:

NAME TOM TOM QTH BOSTON BOSTON GRID FN42 FN42

A shorter version is also easy to understand:

QTH FN42PR

During a contest, follow the exact exchange format required by the rules:

599 023 FN42PR

Avoid adding unnecessary information during a contest exchange. A predictable format makes it easier for the other operator to copy the locator correctly.

Because Maidenhead locators contain both letters and numbers, pay particular attention to:

• Correct character spacing
• The difference between the letter O and zero
• The difference between the letter I and one
• Repeating the complete locator when a fill is requested
• Recording locators in uppercase in your log

How Do You Find Your Maidenhead Grid Locator?

Memorising latitude and longitude is not practical for everyday operation. A locator tool can convert or verify a station position in the standard Maidenhead format.

CW599 has added its sixth CW utility:

Maidenhead Grid Locator

Use it to find or check your grid before operating portable, entering a contest, or creating a new station location in your logging software.

Tool: Open the CW599 Maidenhead Grid Locator

It is a good idea to check your locator when:

• Setting up logging software for the first time
• Moving your permanent station
• Operating from a portable location
• Travelling into another grid
• Entering a VHF or UHF contest
• Working satellites, EME, or microwave bands
• Creating a new LoTW or QSL station location

So, Should CW Operators Use Maidenhead Locators?

The practical answer is:

A Maidenhead locator is not required in every CW QSO, but it can be essential in VHF/UHF operation, microwave work, satellites, EME, rover activity, and distance-based contests.

For an ordinary HF CW conversation, sending your city or general QTH is normally enough. When the other operator asks for your grid, your operating position has changed, or the contest rules require one, you should send the correct four- or six-character locator.

Even if you currently operate mainly on HF, it is worth knowing your home grid. Maidenhead locators are widely used in modern amateur-radio logging, awards, contests, station records, and contact confirmations.

Before your next portable or contest operation, use the CW599 Maidenhead Grid Locator to verify the correct grid for your operating position.

When Everything Fails, CW Still Works.