SOARA Education Series EchoLink 15 November 2007 Howard 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 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

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.

SOARAs EchoLink Node Was Connected in 2004 SOARA operates a link between EchoLink and the San Clemente VHF repeater on 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 UsersCallsignIndividual Nodes, No RF Connections Conferences* Name *Used For Conferences (e.g. Newsline) LinksCallsign –LConnected to Simplex Radio RepeatersCallsign –RConnected to Full Duplex Radios

Typical Keyboard

Echo Link User Commands Check Link Status 08Unconnected, Connected W6XXX Query Status By Node 06Returns node status by node number Query Status By Call 07Returns node status by callsign

Echo Link User Commands (Cont) Connect to NodeA NNNNNWhere NNNNN = desired node number Connect to Call Sign C callsign #See alpha encoding procedure below Reconnect Last Call 09Reconnects to the last connected node

Echo Link User Commands (Cont) Disconnect#Disconnects the most recent connection Disconnect All##Disconnects all connected node Random Node00Selects an available node (of any type) at random, and tries to connect to it.

Echo Link User Commands (Cont) Random Link01Selects an available link or repeater (-L or –R) at random, and tries to connect to it. Random Conference 02Selects a conference server at random, and tries to connect to it. Random User03Selects 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 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 # EchoLink responds with: K-1-R-F-D BUSY Because 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 (Cont) 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 CallOwnerNode NumberType NJ6NBrian5336User NJ6N-LBrian125251Link W5LONTom115514User K6RBSRichard2938Link K6SOA-RSOARA133376Repeater KG6GIHoward109683User GB3DX-RBirmingham, England7125Repeater GB3HE-RHastings, England115293Repeater GB3GN-RAberdeen, Scotland19583Repeater

User Software Acquisition User software and other data can be found at 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 SOARAs Echolink computer at none Brian will respond over the air. 6. Brian will place a call from an radio to Howards notebook computer at node 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 (Windows) (Mac OS/X) Computer/Radio Interface: Building your own Interface

Questions ???