1. VHF Communications for Pilots & Crew Members
Delaware Wing
Civil Air Patrol
The communications mission of CAP is to organize and maintain a reliable, nationwide, point-to-point, air-to-ground, and ground mobile radio capability for use in emergencies and for training communications personnel.
The primary purpose of any CAP communications facility is to provide the commander with the means for controlling his/her units and their activities.
Provides the commander at each echelon the ability to communicate with superior and subordinate commanders.
Capt. Gary Emeigh, CAP
Dover Composite Sq.

2. VHF Communications
Review of CAP VHF Communications, regulations and capabilities
Air-band AM radios vs. CAP FM radios
Protocols and proper operation of aircraft VHF resources
Repeaters – uses and pitfalls
New information on
Altitude and frequency restrictions
Encryption

3. Air-band vs. CAP Radios What’s different
Authorization
Air-band Radios are licensed by the FCC through the FAA
Pilots operate under a radio certificate tied to tail number
CAP mission base has a blanket authorization to operate
CAP Radios are licensed by the NTIC through the Air Force
CAP Radio Stations must be under the direct supervision of a properly authorized Civil Air Patrol radio operator [i.e. have had BCUT as a minimum]
Modulation
Air-band: AM
CAP: FM
CAP radio transmissions may also be digital [P25] and encrypted
Frequencies
Air-band: open to the public
CAP Frequencies designated “For Official Use Only” –
Actual frequencies cannot be disclosed to anyone or broadcast
Not available through the Freedom of Information Act

4. Radio Basics AM vs. FM

5. Amplitude Modulation AM
Worldwide standard for aircraft communication
Very old type of modulation first used in early development of radio
Tends to be noisy, easily interfered with. Allows lots of static and ignition noise. Bad feature.
Allows two stations to be heard over one another – i.e. no capture effect as with FM.

6. Frequency Modulation FM
FM is used by CAP for VHF radios in vehicles, aircraft, walkie-talkies and base stations. Short range.
The advantage is less static from ignition systems in vehicles, and excellent audio quality.
FM also has a “capture effect” where the strongest station comes in over a weaker station.
CAP also uses FM in the ISR UHF radios. 6

7. CAP Radio Equipment and Operation

8. Types of radios EJ Johnson Motorola ICOM Aircraft Radios Base Radio
Mobile Radio
Portable
Motorola HF
800 Mhz
ICOM
ISR
Aircraft Radios
Aircraft use two types:
AM – used mostly by pilots to communicate with Air Traffic Control.
FM – used primarily by Mission Observer to communicate with Mission Base

9. Delaware Wing has the added complication of an 800 mhz radio installed in aircraft for communication with state agencies.
Make certain you have switched the necessary COMM 3 select from 800 mhz (or UHF) to Normal (or VHF) before trying to use the CAP radio.
CAP utilizes one of the two following types of radios installed in aircraft.

10. Technisonic Model TDFM-136 Aircraft VHF CAP Radio
Main: On / Off – Main volume
Guard: Guard channel volume
Squelch: Push for open squelch
MN/GD: Transmit channel select
G1/G2: Sets Guard Channel
Hi/Lo: Power – 1 or 10 watts.
1: N/A
2: Display brighter
3: N/A
4: Channel scroll down
5: N/A
6: Channel scroll up
7: N/A
8: Display dimmer
9: N/A
1, 3, #, 0, 7, 9: USED FOR PROGRAMMING RADIO!
Main and Guard knobs for volume. Use 4 and 6 buttons to select desired CAP channel. 2 and 8 for display brightness. Three switches at bottom left are normally kept up.

11. NPX-138
MN Knob: On / Off and Volume for main channel GD Knob: Guard Channel Volume in Norm position Scan/Norm/GdTX: Keep in Norm position GD1/GD2: Guard Channel 1 or 2 select. Usually kept in GD1 position DISP: - Always Leave on (ID) display CHAN: Toggle left/right to scroll main channel BRIGHT: Display brightness up or down. EDIT: For PROGRAMMING! (Leave in center position) SQ: Press for open squelch

12. ALL DEWG CHANNELS ARE IN ZONE 2
BASE STATIONS and MOBILES
PUSH TO CHANGE
POWER SETTING.
Keep on HIGH.
Display now shows: Command Control 1, Zone 2, and channel 1
TO CHANGE CHANNEL:
Press SELECT knob to move cursor above channel. Turn knob to desired channel.
Channel description changes when you change channel
On/Off Volume
TO CHANGE ZONE
Press SELECT knob to move cursor above Zone as shown. Turn knob to desired zone.
ALL DEWG CHANNELS ARE IN ZONE 2

13. Radio is now in SCAN mode which is a configuration not normally used during SARs.
Press SCAN button to scan all channels, or to stop scanning.
This icon shows radio is scanning

14. Repeaters

15. Simplex vs. Duplex Simplex Duplex Repeaters – Duplex mode
Transmit and receive on the same frequency
Line of sight – Buildings and terrain block signals.
Single Frequency - One Station at a Time
Duplex
Transmit on one frequency and receive on another R T
Two Frequencies - One Station at a Time
Repeaters – Duplex mode
Used to extend coverage and get over obstacles
Repeater increases the range of mobile
stations due to its high profile location

16. DEWG VHF Communications
Delaware Wing maintains 3 VHF repeaters
Locations were chosen to give statewide coverage
Bethel - Northern Delaware
Woodside - Central Delaware
Rehoboth - Southern Delaware
Highbird Repeater * – Utilized by aircraft as assigned by the IC. Requires ACUT operator
VHF Frequencies [Channels] are programmed to show the repeater location [Tag], not the frequency
Frequencies are FOUO – do not say frequencies on the air

17. Aircraft use of Repeaters
Primary mode of operation should be simplex
Only use the repeater if simplex is not possible

18. Delaware Wing Communications

19. Aircraft VHF-FM Radio Channel Plan *
Note: Aircraft Radios do not use Zones
CC1
CC2
AIR1
AIR2
Guard
TAC1
R67
R68
R69
R70
R63
R64
ALT R65
ALT R66
Woodside
Rehoboth
Bethel
Salisbury
Easton
Harford
Lakehurst
Hammonton
SIMPLEX
REPEATERS
[DUPLEX]
CAPGUARD is restricted to use ONLY for initial contact
Aircraft should monitor CAPGUARD to maximum extent possible
* Subject to change
Current as of 30 Jan 2010 for Technisonic TDFM 136 Radio

20. Operating Procedures

21. Identifying Which Radio You Are On
When calling a station on the CAP Assigned FM frequencies, use the Channel Designator in your initial call-up
“Dover Base this is CAP Seven Twenty-Two on Air 1, over.”
DO NOT use “VHF, FM, Foxtrot Mike” to identify the radio equipment you are using
This avoids confusion at Mission Base which may be monitoring different frequencies on several different radios
When calling on the Air-band radio, use normal pilot protocol or announce the frequency
Dover base this is CAP Seven Twenty-two on ”

22. PROWORDS
Prowords are a special set of words used for clarity and brevity in communications.
Some of the most commonly used prowords are:
THIS IS Preface to your call sign
ROGER Last transmission received OK
OVER I’m done, go ahead
OUT I’m done, bye
WAIT I will be back in a few seconds
SAY AGAIN Say that again
CORRECTION Oops! I really meant to say
WILCO ROGER and I will comply
AFFIRMATIVE Yes
In order to create a standard terminology for CAP communicators, a set or prowords has been defined which are to be used whenever they are appropriate.
CAPF dictates use of pro-words on CAP Frequencies

23. I SPELL / FIGURES / INITIALS
Use “I SPELL” to clarify words or when signals are weak
Example: LODI
“I SPELL LODI LIMA OSCAR DELTA INDIA LODI”
Use “FIGURE(S)” AND “INITIAL(S)” for non-words
Example: N
“INITIAL NOVEMBER FIGURES FOUR-SIX, TWO-SIX DECIMAL ONE FIVE ”
Corrections
Use proword “correction”
Example:
“… Turn right at next corner … CORRECTION Turn left at next corner…”

24. QUESTIONS? Questions? Lt. Bill Mervine during Form 5 in
Dover Squadron’s new Highbird