jcarc radio 101 reference document v3 feb 2017 · 2/3/2017 · microsoft powerpoint - jcarc radio...

Radio 101 Reference

Version 3 Feb 2017

https://w7jcr.wordpress.com/

Topics

1. Emergency Communications

2. Radio Modesa. Simplex

b. Repeaters

3. Programmed Frequency List Highlights

4. Radio Propagation

5. FM Modulation

6. CTCSS

7. Internet VoIP Modesa. Echolink

b. IRLP

Emergency Communications

• Practice communicating before the emergency– Wednesday 0900 roll call net Channel 1 = PTREP

– Wednesday 0930 roll call net Channel 12 = MIRPT

– Wednesday 1900 roll call and education net Channel 1 = PTREP

• Maintain supply of non-rechargeable batteries

• Upon disaster or emergency– Take care of you and your family first

– Go to Channel 1 = PTREP (Port Townsend Repeater)

– Listen for a net control requesting and gathering info

– Listen on your neighborhood FRS channel

• Communicate clearly and precisely (radios may be on battery power)

• Alternate EOC– Activated if Main EOC inoperative

– Simplex operation Channel 6 = OPAREA1 (146.4)• Port Townsend, Cape George, Beckett Point, Kala Point, Tri-Area, Marrowstone

www.jeffcoeoc.org

Ham Radio Can Bridge to Beyond Disaster Area

for Health and Welfare Traffic

Yellow = Local Disaster Area

Blue = Regional Disaster Area

Black = Unaffected Area

NormalInternet

Telephone

Distant VHF/UHF Repeater

HF, Satellite

Radio Modes

• Most 2 meter and UHF FM radios– Receive or Transmit at a given time

– Push to Talk, then Release to Listen

• Simplex– Transmitter and receiver on the same frequency

– 0 MHz offset

• Repeater– Transmitter and receiver on different frequencies

– +/- 600 KHz on 2 meters

– +/- 5 MHz on UHF

Simplex mode

• Direct radio to radio communication

– Good for emergency communications

• Just 2 end point radios for complete communication

– Generally limited communication range

• Can be on the output of a repeater if repeater fails because others are listening there

Simplex Radio Communication

TX-1

RX-1

146.4 MHz

146.4 MHz

TX-1

RX-1

146.4 MHz

146.4 MHz

Channel 6 = OPAREA1

Alternate EOC Fire Station 16

TX-1

RX-1

146.4 MHz

146.4 MHz

Everyone can communicate

if within communication range

Ham #1

Ham #2

Simplex Radio Communication

TX-1

RX-1

146.4 MHz

146.4 MHz

TX-1

RX-1

146.4 MHz

146.4 MHz

Channel 6 = OPAREA1

Alternate EOC Fire Station 16

TX-1

RX-1

146.4 MHz

146.4 MHz

What if Ham #1 needs to talk to Ham #2

but they are too far apart or path is obstructed?

XHam #1

Ham #2

Repeaters

• A transmitter and receiver placed in a good

(generally higher) location to receive signals and

simultaneously retransmit or repeat signals

• Transmitter and receiver frequencies are

separated by an offset so that simultaneous

reception and transmission is possible

• Repeaters usually have a time out timer that will

turn off the repeater transmitter if a received

signal lasts more than perhaps 10 minutes

Communication Using a Repeater

TX-1

RX-2

145.15 MHz

144.55 MHz

TX-2

RX-1

144.55 MHz

145.15 MHz

Channel 1 = PTREP

Morgan Hill Port Townsend

TX-2

RX-1

144.55 MHz

145.15 MHz

All communication is repeated from RX-2 to TX-1

Ham #1

Ham #2

Offset=600KHz Offset= -600KHz

Offset= -600KHz

2m and UHF Repeaters in Washington

Programmed 2m and UHF Repeaters

Programmed Frequency List Highlights

RT=Repeater S=Simplex RX=Receive Only

Radio Propagation• Generally visual line of sight on 2m and UHF

• Reflections off of buildings or mountains– Combination of direct and reflected paths can cause “multipath” fading or

distortion

– Moving as little as 6-18” can make or break your signal

– If you find a good spot, do not move around much during contact

• Added path loss if obstructed– Terrain

– Vegetation

– Inside vehicle

– Building

• Relocate to increase height above ground or nearby obstructions– Second floor window

– Speaker microphone allows holding radio antenna higher

– External antenna above roof top

FM = Frequency Modulation

• Stronger radio signals cover up receiver noise or “quiets the receiver”

• Receiver squelch keeps radio muted until a signal is received

• A carrier squelch receiver receives all signals– Useful to hear all signals on a frequency

• CTCSS receivers only unmute when matching CTCSS encoded signals are heard

CTCSS

• Continuous Tone Coded Subaudible Squelch

• CTCSS decode keeps a receiver muted until a desired signal is heard, a repeater for example

• You need CTCSS encode to talk through repeaters

• CTCSS uses 67-250 Hz tones below 300-3000Hz communication voice audio

• Recommended that simplex be carrier squelch with CTCSS turned off

Internet Voice over IP Modes• Regional and Global Voice Communication

• Echolink (~5,455 Nodes Worldwide) www.echolink.org– Radio to Radio

– Radio to Computer (license verification)

– Computer (license verification) to Computer (license verification)

• IRLP (~1,746 Nodes Worldwide) www.irlp.net– Radio to Radio only

• Local Internet probably down– Your VHF/UHF radio might reach to distant Echolink or IRLP node with

undamaged and uncongested Internet

• Documentation and Training soon– Jefferson County Repeater Echolink=714974 (Search for W7JCR)

– Internet to radio only

– Marrowstone Island Repeater IRLP=4251 Echolink=227301 (Search AH6EZ)– Internet to radio and radio to Internet

– Non-standard user interface

jcarc radio 101 reference document v3 feb 2017 · 2/3/2017 · microsoft powerpoint - jcarc radio...

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