N6ICW IRLP Node # 7650
Reflector 9873


145.150 MHz

147.195 MHz

     146.940 MHz

  The N6ICW Repeater System is a member of the Internet Radio Linking Project (IRLP). The aim of the IRLP is to provide a simple and easy method to link radio systems together using the Internet as the communications backbone.

  The IRLP consists of a network of repeaters throughout the world connected together via the Internet. The system was designed and is currently administered by David Cameron, VE7LTD. Each repeater is connected to the Internet through a computer utilizing the Linux operating system.

  Dave designed an interface card and modified existing software to come up with a nearly seamless system for linking repeaters. If you want more information on the IRLP, please visit the website at www.irlp.net.

  As with any new technology, it does take some time to adapt to operating procedures that differ from conventional FM repeater use. This information can serve as a guideline for those using IRLP on the N6ICW System.

  To view the status of all IRLP nodes via the Internet, go to http://status.irlp.net. This is a page that displays in real time, all of the IRLP activity throughout the world. It also contains node numbers, locations and repeater frequencies. 

  Node 7650 is built with a Gateway Desktop Pentium 400 MHz with 128 Megs of RAM and a 80 Gig hard drive. This machine has a built in NIC card and a Soundblaster ISA sound card. The operating system is Linux Fedora 3.01 with IRLP software running under text mode.


  There are two connection modes for an IRLP connection. Direct one-to-one, or one-to-many via a reflector.

  A direct connection is just like it sounds, where node "A" connects directly with node "B". In this mode the two nodes (repeaters) are interconnected and no other IRLP connections are possible. While "A" and "B" are linked, anyone attempting to connect with either node will be informed that- "The node you are calling is currently connected to <node name / callsign>".

  A one-to-many connection utilizes a reflector to connect many IRLP nodes together at one time. A reflector is a computer running special IRLP software. It is not connected to a radio, but rather sits on lots of bandwidth capable of streaming audio to all nodes that are connected. If a direct connection is attempted to a node linked to a reflector, you will be informed that- "The node you are calling is currently connected to <reflector name>".



  Due to the audio delays inherent in a linked system, as well as those added by the Internet connection, it's important that you adhere to the following practice. Wait for a couple of seconds after pressing the PTT button before you begin to speak. This allows for all of the links to get established and ensures that your first few words won't be cut off.

  When the connection is confirmed the voice ID of the destination node will be transmitted back to you as well as your nodes voice ID to the other repeater. After hearing the confirming voice ID wait at least 15 seconds before transmitting as....

The repeater may be in use, and your entry may have occurred between transmissions.

The voice ID of your node is longer than the voice ID of their node, and the connection is not made until the ID is fully played.

Their computer may be slower, and hence take longer to process the connection than yours.

  Press and hold the microphone PTT for a second and then announce your presence and your intention. Are you calling someone specifically or just looking for a QSO with another ham in that city.



  When linked to a reflector, the connection is established the same way as a direct connection, the only difference is the node number. You will hear the voice ID of the reflector when the link is established. Anyone currently on the reflector will not be informed of your presence since no voice IDs are played over the reflector.

  The most heavily used reflector (Ref 9250) is located in Las Vegas. At any given time there are usually 6 to 10 repeaters around the world interconnected via the reflector. You can always check on who is connected to this or any other reflector by visiting http://status.irlp.net and looking for nodes connected to REF x.

  With reflector use, it is critical that you leave a pause between transmissions. By leaving a pause, it allows users on other nodes a chance to check in. More importantly, it allows other node controllers the opportunity to send touch-tone commands to disconnect their node.

  As a rule, connections to the reflectors DO NOT time out with no activity, so it's not unusual for repeaters with minimal traffic to stay connected to the reflector for an extended period of time.



DO pause between transmissions to let others in or others enter DTMF commands.

DO hold your microphone PTT for about 1 second before talking to allow all system time to rise.

DO pause for 10 seconds or when entering the reflector before talking.

DO NOT rag-chew on your local repeater while connected to the reflector.


USAGE OF IRLP on 147.195

.........The N6ICW Repeater System has a tradition of service for the Sacramento Valley. To minimize the impact to local users, the IRLP access is restricted to outbound connections. IRLP is on 24 hours a day for inbound traffic from other nodes using the Denver Reflector 9873. This means that general calls on the system can be answered by those who are listening. Outbound traffic is provided by a control operator. The system control operators are volunteers and provide this service at their discretion.

Control Operators









  The IRLP system is very easy to use and is always a lot of fun. The most difficult thing about using the IRLP system is getting used to the difference between local time and the time zone of the other node.

  Thanks  to Jeff Hillard WA6IOK, Dave Fortenberry NA6DF, John Austin N6SEX, Lou Silva KI6UM, and the late Paul Mezzapelle W6MEZ, for supplying their skills, equipment, knowledge, and support with the installation of node 7650.


© 2012 Chris Huber, All Rights Reserved.