Chapter 8
Field Radios

A field radio is one of the most important pieces of equipment you can take into the field. Radio contact with McMurdo Station, other field parties, and aircraft will make your field season run more smoothly; it can also save your life. This chapter provides instruction on setting up and operating both the High-Frequency (HF) radios and the Very-High-Frequency (VHF), hand-held radios.

Field parties staying in the field for more than 24 hours are required to make a daily safety check-in with the Field Operation Communications Center (FOCC)--call sign MACOPS -- at McMurdo Station, either directly or through a relay with another station or field party if direct communications are difficult.

If a field party fails to communicate for a period of 72 hours, a Search and Rescue (SAR) effort may be initiated.

8.1 HF versus VHF

Radios for field groups are provided by the USAP. Each type of radio issued to field parties has inherent limitations that you should be aware of.

HF radios (the PRC-1099) are considered to be best for long-distance "over-the-horizon" communications. HF radio waves are "bounced" or refracted off the ionosphere and back to Earth. Accordingly, HF communications are susceptible to landmass, and the angle of the "bounce" off the ionosphere may miss ("skip") the receiving station. HF communications are easily affected by magnetic disturbances and sun-spot activity; blackouts can occur for days without warning.

VHF (hand-held and vehicle) radios are "line of sight" radios; therefore, they are unable to transmit through any solid barriers (land formations). On a flat surface, you are limited by the horizon (curvature of the earth) and subtle rolls in the terrain. In the McMurdo vicinity, VHF is augmented on several channels with repeater stations. However, you still have to be in "line of sight" of a repeater for your message to be transmitted.

8.2 Getting Your Field Radio(s)

1. Call the MacElex ET Shop (in the Navy Administration Building 165) for an appointment to pick up your radios.

2. Establish your field party's call sign and a daily safety reporting schedule by completing a "Frequency Assignment Plan" at the Field Operations Communications Center (FOCC), located in Building 165, second floor.

3. Pick up your radios at the ET Shop and attend the ET demonstration class. You need to have your radios in hand before your scheduled Field Safety Training Course

4. Test each of your radios. All field-party radios (and components) must be tested before deploying to the field. This is best accomplished on a Field Safety Training equipment shakedown away from McMurdo. In past seasons, there has been a high percentage of radio failures and operator errors in the field.

Test your radios and all components!

You should plug in the handset of your PRC-1099 radio to the front panel socket (labeled "Audio") before taking it into the field. Leave the handset plugged in because once the rubber washer gets cold, it's very difficult to attach.

5. At camp put-in you must have the following:

Batteries and sufficient power recharging capabilities
for the duration of your field season
Back-up radio (complete)

You must have a radio if a helicopter leaves you in the field, no matter how short your stay may be at that site.

6. At your put-in site, you must immediately establish communications with the FOCC at McMurdo. If you cannot establish communications, you will be flown back to McMurdo. Radio relay via an aircraft does not constitute established communications.

7. At the end of your season, return your radios, batteries, chargers, and antennas to the ET Shop at Mac Center -- not to the BFC.

8.3 HF Radios: Basic Description

The PRC-1099 radio is a single-sideband radio set for operation in the upper sideband (USB) mode. USB is the only mode of operation allowed for use by field parties. The peak transmitter output power is approximately 20 watts. The complete field kit weighs about 25 pounds.

The PRC-1099 will operate to about -30 degrees Celsius. Below this temperature, it is recommended that you keep the radio elevated inside a tent, hut, etc., and keep it as warm as possible.

8.4 The PRC-1099 Radio

* [See figure radio3]

8.4a Batteries and Chargers: PRC-1099

Rechargeable, sealed lead-calcium batteries are used in the PRC-1099 radios. In a cold environment, the chemical reaction in the batteries begins to slow, and available electricity slows down or eventually stops. Therefore, you'll need to recharge or replace batteries fairly often. (Return all used batteries to the ET Shop in McMurdo for proper disposal.)

The PRC-1099 radio contains one battery. The PRC-l099 backpack also contains a battery. It takes approximately 12 hours in full sunlight to fully charge a battery. The PRC-l099 can be operated with the solar charging unit attached.

8.4b Setting up the Antenna for the PRC-1099

1. The PRC-1099 transceiver is ready for operation. No switches need to be set.

2. Unroll the antenna and place all the shorting bars into the corresponding banana plugs, except the plug with the color designated to the frequency at which you want to operate.

Station Frequency Antenna Plug-Ins
Emergency/Aircraft Field Party 8998 kHz All but orange
McM Field Party and Weather Reporting 4770 kHz All but blue
McM Secondary 7995 kHz All but yellow
McM Secondary/Field Party and Weather Reporting 11553 kHz All
Scott Base 5400 kHz All but green

3. Attach the antenna to the antenna cable located in the front pocket of the backpack. Attach the other end of the antenna cable to the front panel connector labeled "ANT."

4. Attach the ends of the antenna and the antenna center block to bamboo poles.

5. Place the bamboo poles so the antenna is elevated as far off the ground as possible, either perpendicular to the station you are calling, or at a 45-to 90-degree angle, with the apex pointing away from the station you are communicating with. The apex should point to your radio set.

Note: In an emergency, if your antenna is lost or damaged, some alternate antenna materials may be used: tent poles, metal crevasse ladders, ice drill extension shafts, pack frames, or snowmobile wiring.

8.4c Setting up the Solar Panel: PRC-1099

1. Remove the solar panel from the front pocket of the radio backpack, open it, and position in a sunlit area. Make sure the panel won't be shaded by tents or equipment. The solar panel is not effective if any of the cells are shaded.

2. Attach the solar panel connector to the front panel connector labeled "ACC".

8.4d Using Your PRC-1099 Radio

1. Attach one end of the cable provided in the backpack to the front panel connector labeled "ANT." Connect the other end of the cable to the dipole antenna cable.

2. Attach the handset to either of the two "Audio" jacks. This should be done in a warm environment; it's difficult to attach in the cold.

3. Turn the "Volume Control" knob until the noise level is comfortable.

4. A flashing light on the display means the battery is low. If it is low, refer to Section 8.4e: Troubleshooting PRC-1099 Radios.

5. Select the desired channel. PRC-1099s have been channelized to the following frequencies:

Station Frequency
Aircraft/Field Party Emergency 8998 kHz
McM Field Party (Dry Valleys and surrounding area)/Weather Reporting 4770 kHz
McM Secondary 7995 kHz
McM Secondary/Field Party and Weather Reporting 11553 kHz

Note: If the memory is inadvertently dumped, rechannelize the radio by following the steps below:

1. Set Channel switch to "MAN."

2. Turn the Digit switch up or down to select the desired digit. The selected digit will flash.

3. Turn the Tune switch up or down to select the correct number.

4. To change frequencies in channels l-8, set the Channel control to desired channel number, press/hold the whip tune button and repeat steps 2 through 3.

5. Turn the Function switch to "USB."

6. Set the power toggle to "HI."

7. Press the transmit button on the handset's side to transmit.

8.4e Troubleshooting PRC-1099 Radios

Make sure you're in "HI."
Make sure you're on "USB" on the Function switch.
Check all connections.
Make sure all antenna shorting plugs are connected properly for your frequency.
Problem Possible Reason(s)
No Power/Low PowerDead/weak batteries or solar panels not properly attached.
No Transmit Faulty handset/antenna connection. Not enough voltage. Front panel display flashes In the event that power is interrupted at MACOPS. Try 11553 kHz (South Pole) or 5400 kHz (Scott Base).

Incorrect shorting plugs attached to the antenna.

No Receive Handset poorly connected. Volume control too low (control must be set at mid-range).

8.5 Time Signals

Standard radio and audio frequency transmissions are made continuously by the Central Radio Propagation Laboratory, National Bureau of Standards, Washington, D.C., over stations WWV and WWVH. Both stations broadcast on 5, 10, and 15 MHz (15,000 kHz). Signals are sometimes weak in the mornings.

These broadcasts are interrupted at times for maintenance purposes. The standard audio frequencies are interrupted at two minutes before each hour, and every five minutes thereafter (e.g., 1958, 2003, 2008, etc.), resuming after an interval of two minutes. Thus, you can take a series of checks at, say, 2000, 2005, 2010 etc. During the two-minute intervals, Eastern Standard Time (GMT minus 5 hours or NZ time minus 17 hours) is announced by voice, and GMT time is signalled slowly in morse code.

A 0.005-second pulse may be heard as a faint click every second, except for the 59th second of each minute; this gives a warning of the return of the audio tone exactly on the hour, 5 minutes past, 10 minutes past, etc.

The BBC's General Overseas Service also broadcasts its "six pips" time signal on the hour throughout the day, and is accurate to one tenth of a second. (The sixth pip marks the minutes, e.g., 2000, 2300 etc.) These can be picked up in the usual shortwave bands between 9.0 and 9.8 MHz, 11.6 and 12.1 MHz, and 15.0 and 15.5 MHz.

8.6 Radio Emergency Action

8.6a Sending a Distress Message

In an emergency, stay calm, assess the situation, and use the following steps to call for help:

1. Select the correct frequency.

2. Speak clearly and take your time.


4. Listen for a reply.

5. When a reply is received, tell the other station who you are, where you are, the nature of your emergency, and that you are trying to make contact with MACOPS at McMurdo Station. Give any information that may assist a rescue operation.

6. If no reply is received

Check your equipment. Repeat your call at regular intervals and allow listening periods between calls.

8.6b Action on Receipt of a Distress Message

1. Listen carefully. Write down the message and time received.

2. Listen for an acknowledgment from McMurdo or other major station.

3. If another station does not acknowledge, acknowledge the distress call and then retransmit the distress message to McMurdo, using the words MAYDAY Relay, MAYDAY Relay, MAYDAY Relay. This is. . . (give your station call sign three times).

4. Give the distress message as broadcast by the station in distress.

5. Give assistance to the station in distress if possible. Advise McMurdo of what you're doing.

6. Continue to listen in.

Unnecessary traffic should be avoided at all times!

8.6c Cancellation of Mayday Messages

If/when help is no longer required, don't forget to announce cancellation of your distress or urgency call!

8.7 Communications Procedures for Fixed-Wing Aircraft

LC-130 aircraft (Hercs) are capable of communicating on any of the frequencies programmed into the PRC-1099 radio. Aircraft communications with field parties will normally occur on 8998 MHz. If an aircraft cannot be reached on that frequency, try 4770 kHz or 11553 kHzor MACOPS.

Hercs are identified by the call sign prefix "X-Ray Delta" followed by the large number painted on the aircraft's fuselage. The call sign for Aircraft One would be "X-Ray Delta Zero One."

Assuming you are Event S-001, proper communications would proceed as follows:

You: "X-Ray Delta Zero One, This is Sierra Zero Zero One, Over."

LC-130: "Sierra Zero Zero One, This is X-Ray Delta Zero One, Copy You Loud and Clear, Over."

You: "X-Ray Delta Zero One, This is Sierra Zero Zero One". . . (Proceed with your message. . . )

8.8 VHF Radios

VHF radios are used for local, "line-of-sight" communications, such as between your field party on the sea ice and McMurdo, or between field-party members working some distance from a base camp. The USAP currently uses MX300 and SABER hand-held radios.

VHF radios can be used in the field only if you will be operating in "line of sight" of MACOPS or a VHF repeater. If you are out in the field for more than 24 hours, you will need a HF PRC-1099. VHF (hand-held) radio batteries will go dead in the cold after 24 hours.

A limited number of experimental solar rechargers are available for VHF radios and batteries.

8.8a Operation of Handheld Radios

1. Ensure that both the battery and antenna are properly attached.

2. Select the proper channel for the area you are in and type of operation (see the following table for frequencies).

3. Turn the radio on.

-MX300-R and SABER at volume control. -Midland at switch on side of radio.

4. Turn the squelch on until a "hash" noise is heard. Set the volume control to a comfortable listening volume, then back off the squelch control until the noise ceases. Inability to get the noise often indicates low or no battery charge.

5. Listen to ensure you won't be transmitting over the top of other transmissions. "Stepping" on other transmissions will cancel them both.

6. Hold the radio in a vertical position. Press the transmit button on the side of the hand-held (or the top of the extension mike). Talk slowly and clearly.

CH VHF-FM Channel Name
1 143.0 143.0 I-Net
2 139.6 139.6 Crash Net
3 142.8 138.8 NZ Portable Repeater
4 139.3 143.8 NZ Crater Hill Repeater
5 142.6 142.6 MCC Net
6 139.2 139.2 PW Net
7 139.5 139.5 Science Net
8 138.6 143.225 Field Party Ops Repeater
9 143.6 143.6 Fuels Net
10 139.8 143.725 Crater Hill Repeater
11 143.4 143.3 Helo Ops
12 143.2 143.2 Penguin Ops

Note: All MX-300 SABER and Midland radios issued to field parties are programmed with the same channelized frequencies.

8.8b Troubleshooting VHF Hand-Held Radios

Problem Possible Reasons
No Power Dead battery.
Poor battery connection.

Inability to adjust the squelch often indicates a low or dead battery. (Batteries will last longer if you keep both the radio and batteries warm under your clothing.)

Mode select switch is flipped to the wrong position.

No Transmit Out of "line of sight" with receiving party or repeater. Try climbing to higher ground -- even holding the radio as high as possible with a remote clip-on mike will sometimes help. Moving away from a vehicle may enhance transmission.

Try transmitting to other stations, field parties, or repeaters that are not in a "shadow" (Williams Field, Scott Base, Vanda, Field Safety Training, Marble Point, etc.) and ask for a relay.

Poor antenna connection.

Low battery. Weak light or no light indicates no power.
Check battery.

Faulty hand mike.

Repeater may be down. Trigger the mike/transmit switch and release. If you are operating through a repeater, a noise burst should be heard for approximately one second. If there is no noise, you are either not transmitting or receiving, or the repeater is down. Try another channel.

No Receive Weak battery. Check both the squelch and mode select switches.

Party transmitting may have a weak radio, or poor vantage point for transmitting. Get to a better site for reception or ask for a relay from another station or party.

If party transmitting is coming across poorly, try breaking squelch to receive weak incoming signal.

8.8c Troubleshooting Vehicle-Installed VHF Radios

Problem Possible Reasons
No Power Radio disconnected.
Fuse blown.
Ignition is not turned on.
No Transmit Faulty mike.
Faulty or disconnected antenna.
Wrong channel.
No Transmit Out of "line of sight" with receiving party or repeater.. Try another channel. Try for a relay/radio check.
No Receive Faulty antenna.
Faulty speaker.
Test speaker with squelch.
Try a radio check.

8.8d MCX-1000 Problems

Many of the new, digital MCX-1000 VHF radios are directly hooked up to the vehicle's batteries. If the MCX-1000 is not turned off and the vehicle is not running, the radio will rapidly drain the vehicle's battery.

Note: When the vehicle's batteries go dead, and the vehicle is subsequently jump-started by the Heavy Shop, the jump start will create a power surge and short out the radio's programming if the radio is not turned off. If this happens, the radio will need to be reprogrammed by the ET shop. To test for this problem, turn the radio on (at the volume control). The radio will perform a self test function. If the radio remains in the self test mode for more than one minute, or gives a fail indication, notify the MEC (if a science vehicle) or the ET Shop.

8.8e VHF Communications Procedures For Helicopters

You must have a radio if a helicopter leaves you in the field -- no matter how short your stay may be at that site.

A helicopter's primary means of communication with the field parties will normally be on VHF Channel 8 (FP Ops: TX-138.6, RX-143.225). Secondary communications by PRC-1099 (HF) is normally on 8997 kHz. HF communications should be prearranged with the VXE-6 helicopters prior to departure.

VXE-6 helicopters are identified by the call sign prefix "Gentle" followed by the large number painted on the aircraft's fuselage. Helo Number Eleven would be "Gentle One One."

Assuming a helo is too far away to see, and you are S-001, proper communications would be as follows:

You: "Gentle, Gentle, This is Sierra Zero Zero One, Over."

Helo: "Sierra Zero Zero One, This is Gentle One One, Copy You Loud and Clear, Over."

You: "Gentle One One, This is Sierra Zero Zero One. . .(proceed with your message)"

8.9 Radio Alphabet and Morse Code

 .  = "dit"     -  = "dah"
AlphabetMorse CodeMorse Code Abbreviations
AAlpha dit-dah AA All after
BBravo dah-dit-dit-dit BB All before
CCharliedah-dit-dah-dit CC Break/I wish to interrupt
DDelta dah-dit-dit CFM I confirm
EEcho dit CL I'm closing my station
FFoxtrot dit-dit-dah-dit CQ Call any station
GGolf dah-dit-dah-ditDEThis is an identifier
HHotel dit-dit-dit-dit E East
IIndia dit-dit ER Here
JJulietdit-dah-dah-dahETAEstimated time of arrival
KKilodah-dit-dahK Transmit now, I'm listening
LLima dit-dah-dit-dit KTS Knots
MMike dah-dah MIN Minutes
NNovember dah-dit N North
OOscar dah-dah-dah NO Negative
PPapa dit-dah-dah-dit NW Now
QQuebec dah-dah-dit-dah OK I agree
RRomeo dit-dah-dit PSE Please
SSierra dit-dit-dit R Message
TTango dah REF Reference to
UUniform dit-dit-dah RPT Repeat
VVictor dit-dit-dit-dah S South
WWhiskey dit-dah-dah TFC Traffic
XX-ray dah-dit-dit-dah TU Thanks
YYankee dah-dit-dah-dah W West
ZZulu dah-dah-dit-dit WA Word after
1 One dit-dah-dah-dah-dah--
2 Two dit-dit-dah-dah-dah--
3 Three dit-dit-dit-dah-dah--
4 Four dit-dit-dit-dit-dah--
5 Five dit-dit-dit-dit-dit--
6 Six dah-dit-dit-dit-dit--
7 Seven dah-dah-dit-dit-dit--
8 Eight dah-dah-dah-dit-dit--
9 Nine dah-dah-dah-dah-dit--
0 Zero dah-dah-dah-dah-dah--

8.10 Ground to Air Emergency Signals

The following two pages contain diagrams of ground to air emergency signals. If radio communications with aircraft are not available, you can communicate with these signals.

* [See figure ³radio4²]

* [See figure ³radio5²]

On to Section 9: Weather