Reflector  Connection Guidelines

To assure proper operation of the reflectors there are certain minimum requirements that connecting nodes must meet

IRLP - Keeping the Radio in Amateur Radio

To assure proper operation of the reflectors there are certain minimum requirements that connecting nodes must meet.  These mandatory requirements are necessary to assure those using the reflector do not receive unintentional interference from improperly adjusted or configured nodes.

  • No repeater tail or any other signal that may keep your nodes COS high when no input signal is present to the node  receiver.  This includes attempts to notch or turn down the audio on CW ID that still results in a COS signal being sent to the IRLP network and thus an un- modulated carrier on all connected nodes

  • No Courtesy tones or CW ID to the IRLP other than the occasional CW ID that is overlaid with a voice transmission due to someone transmitting over their local ID. 

  • No pulsing of the node.  This requirement has ZERO tolerance for reason listed below  

Pulsing is the single most important item we must prevent and is also the most common reflector issue.  Since  it is difficult for an offending node to detect this without being proactive, a node can be pulsing and not know it. 

A pulsing node is one that sends a COS signal to the IRLP network each time another node stops transmitting.  The result is that the pulsing  node keys up all connected nodes to the reflector each time the carrier of other nodes drop.  If two pulsing nodes are connected to a reflector at the same time, it grinds to a halt as the two pulsing nodes will ping- pong pulse each other making the reflector unusable.

The easiest way to eliminate both of these issues which almost always eliminates pulsing is as follows:

  • Add a PL (CTCSS) Encoder to the repeater transmitter

  • Configure the encoder so it only sends PL when the COS repeater receiver is a valid signal

  • Take your COS point on the link radio from a point where the active state is only present with a valid PL tone 

If you use the above interface your repeater courtesy tail and ID will never be heard on the IRLP and chances are the default 150 mSec pulse timing will do just fine.  

First of all run the PulseCheck utility outlined in the After The Install Document. After making the settings outlined there you should connect to the Echo reflector and watch the green COS led on the IRLP board when the echo transmission drops. If you see the COS led pulse or come on for any duration you may be pulsing.

If mounting in the Linux box makes it impossible to see the LED then do the following

Log into the node as user Repeater and then run 'readinput'.  This will monitor all node PTT and COS states as well as log any decoded DTMF digits.  

  • Make a test transmission to the echo reflector 

  • As your node transmitter un-keys your screen should display 
         <PTT INACTIVE>     

  • If your screen displays 
          <PTT INACTIVE>
          <COS ACTIVE>
          <COS INACTIVE> 
    when the PTT ends - you are pulsing and need to determine why.

The above is to be considered mandatory requirements for connecting to a reflector.  Some reflector owners may have a more relaxed position however you need to build to the above requirements to assure 100% compliance. 

Enjoy IRLP and please "Pass the Word"
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last updated February 14, 2007
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