^{_Introduction}

If you know me, you’ll know I have my own repeater on the WIN system repeater network. It uses Allstar as the connection to the WIN system. One of the common conversations I hear on the system is on the topic of nodes, what a node is, and owning your own node. Many don’t even know what that is or what it looks like to have one. It’s OK, this page is here to un-pack all of that. Because there are so many options available, I decided not to provide a step by step on building your own node, but to guide you as to an overall picture as to what you’re getting into. There are plenty of tutorials out there on how to build your specific node. If you wish, you may skip to the bottom for a great deal on a ready-made node that just plugs into a Raspberry Pi and it’s ready to sing.

IRLP or Allstar?

IRLP (Internet Radio Linking Project) is an amateur radio VOIP linking protocol which like Allstar allows the connection of radios via VOIP over the Internet. However IRLP has many limitations compared to Allstar. Allstar is a totally free system and with few exceptions you can do what you want on Allstar. Allstar polices its own system and in most cases as long as you are within FCC rules you can experiment away. On the other hand IRLP is administered by one or a group of individuals. Unlike Allstar there is no access to the source code, so enhancements by the community just doesn’t happen. There is little room for experimentation. Additionally, IRLP allows connections to only one other node at a time, whereas on Allstar, you’re allowed to connect to multiple nodes and build your own network. IRLP does offer what are called reflectors however. These are special nodes run by an administrator where multiple nodes can connect. You could think of this as just like a hub in Allstar, although like everything else in Allstar, a hub would probably be far less formally defined or run. Think of an IRLP reflector as an officially run chat room with a moderator and rules. An Allstar group though is organically built by anyone by just connecting nodes together. An Allstar network doesn’t necessarily need a hub (unless many connections would otherwise burden the nodes connecting a large number of stations), but an IRLP connected network needs to go through an official reflector. So without further discussion, we talk Allstar from here on.

Node basics

If you’re a Ham and operate a handheld into a repeater, you’ve undoubtedly had the experience of not being heard well, and you may not hear the person you’re trying to talk to well. Many that would like to use the WIN system, but they just can’t reach a WIN system repeater from where thy are or are only marginally able to reach a repeater. There may not be a repeater in your area that reaches the network you want to use. The repeaters for the WIN system around the globe use the Internet to stay connected, so the common question is, “Since I have my own Internet service, why couldn’t I bypass the need to reach another repeater, and make something where my radio can connect to the WIN system directly using my Internet?”

Turns out you can, and there are a number of ways to do it and it’s called having your own node. Any connection to the Internet intended to talk into a repeater system is called a node. A node can be in the form of a repeater, a simplex connection , or just a microphone and speaker connected to a computer using no radio at all.

In terms of using only a computer or smartphone to talk directly into the network, the Win system’s rules of operation heavily discourage the use of just a mic and speaker on a computer as it’s not using a ham radio transmission. WiFi, even though it’s technically wireless, doesn’t meet the criteria of ham radio transmission. So going forth, we will focus on a means of connecting you to a repeater network using your UHF/VHF radio as the endpoint.

Allstar node number

Regardless of what kind of node you set up, you will need to create an Allstar account and apply for a node number. Go here to get started.

While you’re waiting for your node number, start planning. All nodes will require some sort of computer. The most recommended CPU is a Raspberry Pi, mostly because you can get one for around $35-100, and thy have proven to be most reliable. The Pi 3 will run you around $50 with case and power supply, it’s the one I run my repeater on. A Pi 4 will be $200 or so once you purchase the case and fan. The Pi 3 does not require a fan and will support multiple nodes. Update: Because of the chip shortage, Pi’s have gone way up in price. This is a reliable SBC for $59 from Amazon and should work fine. The specs look like it will run circles around the Pi.

The second item is a URI (USB Radio Interface). The DMK URI is the most ubiquitous but there are others out there, or you can modify a $8 sound fob to do the job.

DMK URI Page. The DMK URI has gone up in price and now sits at about $120.

Here’s a cheaper alternative but has a DB9 connector rather than DB25 connector to connect your radio:
Masters RA33 (with audio level adjustments, recommended)

Or you can get PAUL, or a DINAH, a URI with a packet radio interface that plugs directly into almost any mobile radio without modification using the packet radio jack.

Roll your own URI using an $8 sound fob from Amazon.

This piece from Amazon has the CM108 chip exposed so that you can easily modify it. Many comments say this is the one to use for the radio interface. I suggest you encase the parts area in hot glue or silicone after doing all your modifying to protect it, as this doesn’t come with a case.

Here’s a Tutorial for adapting USB sound fob:

The 3rd item needed is a node radio. Yes, it takes two radios to do this– the endpoint being the HT you cary around and talk into, and the node radio that receives your signal that connects to the URI that translates the audio to a USB signal, and to the Internet. A Baofeng 888 can be had for as little as $20. Here’s the tutorial. There are many other radios are out there, and many mobiles have no modification required. Alinco, Yaesu, and Kenwood mobile radios all have connectors on them, and there are ready made cables that plug directly to a DB25 URI interface. The RA33 URI would need pin realignment.

Node Type

What do you want to do? The type of node and the combination of hardware and radio equipment is diverse. There are a number of ready-made products out there or hardware available for you to roll your own. Here is a picture of a typical roll-your-own simplex node.

If opening up a radio and soldering wires to a $5 USB sound fob is something you’d like to tackle, You can spin up an Allstar node and be talking on it with as little as $20 (if you have your own PC to dedicate to it). You will need to modify the Baofeng BF888 and the $5 sound fob, but many have made it work.
For a professional repeater system with all the trimmings, north of $5000 isn’t unlikely depending on your environment. A 50′ crank-up tower can run $10K alone.

Difference between a simplex and repeater node

A repeater receives on one frequency and transmits on another. That means two or more people can hear everything even if what’s spoken is a local transmission. This also means two people can use the node to have a local QSO. Another nice thing is that one doesn’t have to wait for the carrier to drop in order to break in with a comment. A simplex node however is a bit more cumbersome to use. You can’t speak until the carrier drops, so if there’s interference causing the network to stay transmitting, you can’t talk. It’s because on a simplex node, you use only one frequency to transmit and receive. All you can do is communicate with whoever is coming in on the network, not local. A repeater requires two radios, a duplexer, and coordination of a pair of frequencies from a coordination authority. Most urban communities have no more pairs to assign. Simplex is more relaxed. Generally a low power duck antenna is all you need, and the range is usually less than 1/4 mile. Just find a simplex frequency that no one is using and go for it.

How-to program your Raspberry Pi (or PC) for Allstar

There are so many tutorials for preparing your CPU to be an Allstar node. One thing of note, there are a couple of images out there– both have their up and downs. One is from Allstarlink.org the other is the Hamvoip site. Hamvoip is the one I use, but I will provide links to both.
Allstarlink tutorial
Hamvoip tutorial

Ready-Made Simplex Node

This is a ready-made Allstar simplex node and radio that plugs directly into your Raspberry Pi and it’s ready to go. It’s called SHARI. The Pi 3 will run you $55 or so and SHARI costs about $90. This is the best price you’re going to find for a plug and play no fuss solution that includes everything. The URI and node radio are also included. All you will need to supply is your Allstar node number and a Pi. Find an un-used frequency in your area and enjoy. Here’s the link:
https://kitsforhams.com/shari