AmateurRadio.com

The history of the Internet Radio Linking Project (IRLP) goes all the way back to the last century when David Cameron, VE7LTD created it. His was an effort to link repeater systems across Canada using the Internet. Since then, the system has evolved, matured and grown. And it’s still growing. Today, there are nearly 1700 active nodes around the globe.

I built an IRLP node (4212) way back in 2003 and have operated it as a simplex UHF node in my home ever since. With it and my handheld transceiver, I’m only ever just a few touch-tone presses from linking my system to repeaters and other simplex nodes around the planet.

These days, much attention is heaped on D-STAR, the growing digital network promoted by ICOM. Digital systems have some advantages that might be very useful going forward in the amateur service. I use and support the continued deployment of D-STAR, but if you’re thinking about diving into linked systems, I can think of five good reasons why IRLP should be considered before taking the digital plunge:

1. IRLP uses standard FM. There are few radio amateurs who don’t already have a standard two meter or 440 transceiver at their disposal. D-STAR equipment is generally more expensive, and it obsoletes perfectly good hardware.
2. D-STAR systems usually require all new repeater hardware. IRLP can make use of existing, standard FM repeater installations with the addition of some simple equipment. Clubs don’t have to chuck their previous investment in their repeater system to deploy IRLP.
3. If you can push-to-talk and press a few touch-tone keys, you can link your local IRLP system to others. D-STAR equipment is much more complex to use. Programming software is generally employed to make the task of setting the new D-STAR radio up a bit easier but despite ICOM’s best efforts to make it simple, it remains a steep learning curve.
4. The D-STAR system can be accessed directly via the Internet via the DV-Dongle. While this could be seen as an advantage, radio purists will blanch at the notion of operators “getting on the air” directly via the Internet. Sure, the Internet provides the backbone for IRLP, but it’s a system design requirement that real radios are required on both ends of an IRLP link. That’s why VE7LTD used the “keeping the radio in ham radio” motto.
5. And then there’s the audio. Listening to an FM transmission from a properly adjusted ham radio repeater is a joy. D-STAR audio on the other hand is compressed, tinny-sounding. It’s not a showstopper and most D-STAR fans will tell you they have grown to prefer the pinched audio. Still, the first impression of many is that the audio is painfully compressed.

I might also add that IRLP is available over a wider geographic region than D-STAR. That’s probably due to its ease of deployment, lower investment, and the five year head start it has on digital systems.

Linked VHF/UHF repeater systems aren’t for everyone, but I see plenty of utility in amateur radio having its own “intercom” system that provides reliable, stable, enjoyable communications — when the Internet is up and all systems are “go”.

Filed under: Ham Radio Tagged: dstar, irlp