SOARA Education Series

EchoLink

15 November 2007Howard Brown, KG6GI – Repeater Director

Brian Roode, NJ6N – Software Engineer

Voice over Internet Protocol

The Internet is an vast network of computer networks.

The Internet Protocol (IP) is responsible for moving data between computers on the world wide Internet.

Voice over IP (VoIP) is used to provide voice communication between computers over the Internet using IP.

VoIP involves periodically sampling the audio stream and encoding the information to conserve bandwidth.

Amateur Radio use of VoIP

There are several VoIP applications used in Ham Radio:D-Star, EchoLink, IRLP, Skype, eQSO, Wires-II

(Yaesu) are some of the VoIP Applications in use today.

EchoLink has over 200,000 registered users in over 162 countries!

EchoLink

Jonathan Taylor, K1RFD, won the Dayton Hamvention's Special Achievement award in 2003, for writing and developing EchoLink and EchoStation.

EchoLink software is available for Windows, Macintosh OS/X and Linux, free of charge.

Getting started with EchoLink

Hardware & Software Requirements Personal Computer/Sound Card Interface Headset (Best) or Microphone & Speaker (Good) EchoLink Software Valid Amateur Radio License

Download & Install the software Standard Windows software installation Follow the on-screen setup “Wizard” to configure

EchoLink. A unique node number will be automatically assigned to

you after your call-sign has been verified.

Users, Links, Repeaters, Conferences!

There are several different node types: Users: Stations that are using a personal computer. Links: Stations with computers running EchoLink

interfaced to a local radio transceiver. These stations are designated by their call-sign followed by “-L”.

Repeaters: Stations with computers running EchoLink interfaced to an FM repeater through a repeater controller. These stations are designated with their station call-sign followed by “-R”

Conferences: Special interest “chat rooms”

Computer Controls

Double clicking the speaker icon in the startup area will bring up a mixer panel

The ‘Playback’ panel audio output from the sound card

The ‘Recording’ panel audio input to the sound card

Check ‘mute’ box for all unused inputs & outputs Be sure that the path from the input to the output is

disabled

Audio Set Levels Probably the most complex issue is level audio setting Best approach is to inject a 1 KHz test tone at -6 dBm. An adjustable

tone generator is available within Echolink (See Tools/Tone Generator…)

Set Line Out control (on Playback panel) to produce a 1 volt p-p signal out of the sound card

Set interface transmit levels to produce 2.5 KHz deviation. While listening to the repeater, set radio and interface levels to produce

a 1 volt p-p signal into the sound card. Set Line Input controls (on Recording panel) to generate a mid point

level in Echolink This procedure will provide 2:1 modulation headroom (i.e. the audio

signal can double in amplitude before the limiters start clipping

Important Firewall Issues

A Firewall or “Cable/DSL router” is a device that shields your computer from unwanted inbound connections.

You will need to configure the router to "forward" UDP ports 5198 and 5199 to the PC on which EchoLink is running. It must also allow incoming connections on TCP port 5200.

Software Firewalls, including the built-in firewall on Windows XP must be configured to enable EchoLink.

Some routers or model/routers prohibit configuration changes See Echolink web site for extensive data.

Typical System Configuration

146.025Repeater

IC-706Radio

TX Audio

RX Audio

PTT

COS

UltimateLinkingInterface

(ULI)

PCRunningEchoLink

Line Audio Out

Line Audio In

‘T’ = Transmit‘R’ = Receive

‘C’ = Control KeepAlive

Control

Internet

Link Operation

Link Interfaces interconnect your radio transceiver to your computer.

This enables you to use EchoLink from an HT or mobile radio, remotely.

Interfacing enables many other digital modes including PSK31, SSTV, RTTY, etc.

Interfaces

There are quite a lot of commercially available interfaces available as kits or pre-assembled and tested versions.

Basic interfaces provide minimum interfacing necessary to get on the air.

Advanced interfaces provide additional features such as remote rig control, local microphone and PTT control, computer reset via RF, etc.

SOARA’s EchoLink Node Was Connected in 2004

SOARA operates a link between EchoLink and the San Clemente VHF repeater on 146.025+

This link was previously pointing to the 440 repeater on Temple Hill but was relocated with installation of D-Star

Members of SOARA can initiate connections through the repeater with other EchoLink subscribers that are connected to the Internet

SOARA Privilege

Outbound EchoLink usage is a privilege limited to SOARA members.

A code is required too initiate connections to remote amateurs.

The repeater codes are confidential. You may hear some unfamiliar voices, - give

them a shout and you will probably find yourself working DX!

Types of Users

Users Callsign Individual Nodes, No RF Connections

Conferences * Name * Used For Conferences (e.g. Newsline)

Links Callsign –L Connected to Simplex Radio

Repeaters Callsign –R Connected to Full Duplex Radios

Typical Keyboard

Echo Link User Commands

Check Link Status

08 “Unconnected”, Connected W6XXX”

Query Status By Node

06 Returns node status by node number

Query Status By Call

07 Returns node status by callsign

Echo Link User Commands (Con’t)

Connect to Node A NNNNN Where NNNNN = desired node number

Connect to Call Sign

C callsign # See alpha encoding procedure below

Reconnect Last Call

09 Reconnects to the last connected node

Echo Link User Commands (Con’t)

Disconnect # Disconnects the most recent connection

Disconnect All ## Disconnects all connected node

Random Node 00 Selects an available node (of any type) at random, and tries to connect to it.

Echo Link User Commands (Con’t)

Random Link 01 Selects an available link or repeater (-L or –R) at random, and tries to connect to it.

Random Conference

02 Selects a conference server at random, and tries to connect to it.

Random User 03 Selects an available single single-user) at random, and tries to connect to it.

Examples of Node Number Connection Establishment

To connect to node number 9999: Enter: A 9 9 9 9 Echo responds with:

“CONNECTING TO CONFERENCE E-C-H-O-T-E-S-T”

followed by: “CONNECTED”

Because 9999 is the node number of conference server “*ECHOTEST*”.

Callsign Entry

To enter a callsign press two digits for each character in the callsign.

The first digit is the key on which the letter appears (using 1 for Q and Z), and the second digit is 1, 2, or 3, to indicate which letter is being entered.

To enter a digit, press the digit followed by 0. When finished, end with the pound key (#).

For example, the letter “K” is entered as “52”, the letter “Q” is entered as “11”, and the digit “7” is entered as “70”.

Examples of Connection By Callsign

To get to the status of K1RFD: Enter: A 0 7 5 2 1 0 7 2 3 3 3 1 #

EchoLink responds with: “K-1-R-F-D 1-3-6-4-4 BUSY”

Because 13644 is the node number of station K1RFD, and K1RFD is currently busy.

Examples of Random Link or Repeater Connection

To connect to a random link or repeater: Enter: 0 1 EchoLink responds with:

“CONNECTING TO K-1-O-F REPEATER” followed by

“CONNECTED”

Because K1OF-R was selected at random.

Callsign Entry (Con’t)

Callsigns need not be entered in full. If a partial callsign is entered, EchoLink will find

the first match among the stations currently logged on.

If no match is found among the stations currently logged on, EchoLink will say “NOT FOUND”.

Some Node Numbers

Call Owner Node Number Type

NJ6N Brian 5336 User

NJ6N-L Brian 125251 Link

W5LON Tom 115514 User

K6RBS Richard 2938 Link

K6SOA-R SOARA 133376 Repeater

KG6GI Howard 109683 User

GB3DX-R Birmingham, England 7125 Repeater

GB3HE-R Hastings, England 115293 Repeater

GB3GN-R Aberdeen, Scotland 19583 Repeater

User Software Acquisition

User software and other data can be found at http://www.echolink.org

The user will need to have his callsign validated by the EchoLink Support Group Typically takes less that one day

Critical consideration for those using a hardware or software firewall is enabling inbound ports: UDP ports 5198 & 5199 are forwarded to local computer TCP port 5200 is forwarded to local computer

Typical Router Setup

Demonstration of EchoLink

1. Display list of ‘On-The_Air’ Stations

2. Play recording of typical QSO

3. Display system log.

4. Connect to the ‘Echotest’ function to verify levels and clarity

5. Place a call from a remote computer to SOARA’s Echolink computer at none 133376. Brian will respond over the air.

6. Brian will place a call from an radio to Howard’s notebook computer at node 109683. Howard will respond over internet.

7. If time permits, Brian will place a call to a specific party or use the random feature.

For more information:

QST Magazine, February 2003, pg. 44. Software

http://www.echolink.org (Windows) http://www.dogparksoftware.com/EchoMac.html (Mac OS/X)

Computer/Radio Interface: http://www.ilinkboards.com/ http://www.westmountainradio.com/ http://www.packetradio.com/rascalmkv.htm http://ilinkca.com/

Building your own Interface http://www.qsl.net/wm2u/interface.html

Questions

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