What it does:
This station listens for and decodes APRS packets from other stations and “gates” them to the internet. These other stations can be mobile (vehicle or pedestrian) or fixed stations (like digipeaters).
When APRS is being used, any other APRS-capable radio can decode the packets being sent out (either natively on the radio, or through connection to a computer of smartphone). So if you and a friend are using APRS in the middle of nowhere and are within simplex range of each other, you can receive positional information or messages on your radios from each other.
But that only works for certain things. If you’re looking at using APRS for tracking your buddy, but they’re outside of simplex range, you would need to employ a digipeater. They listen for APRS traffic and re-transmit those packets to a wider area. This is very similar to how regular amateur repeaters work for voice operations. The repeater is in a prime location and can usually transmit at a higher power level using better antennas for better range. APRS paths usually allow for multiple hops between digipeaters to not only help with range, but also to allow for a higher chance of being picked up by a station running an I-Gate.
Which brings us to I-Gates!
Now, for example, if you’re looking at tracking your progress during a roadtrip, then an I-Gate is a must! Some digipeaters have them built-in already, while others do not. It depends on what equipment is available to the digipeater owners, the local network needs, and a few other factors.
If you traveled from Montreal to Las Vegas and were firing off packets every 60 seconds or so, there should be stations well away from your location that can see where you are. The only thing is, those packets are heard, displayed when received (maybe logged in a file somewhere), and that’s it. Throw an I-Gate station into the mix and everything that it hears is uploaded to the internet. Connecting to the internet allows positional information to be viewed on sites like aprs.fi.
That’s what this thing does:

This I-Gate regularly receives packets digipeated from VE3OCR-2 in downtown Ottawa, as well as simplex packets from nearby mobile stations. Checking the information for VE3OCR-2, it can be noted that it is not gating any data to the internet, just repeating it back out over RF.

There are other stations in the area that digipeat AND gate, such as VE3SHQ located at the Scouts Canada Museum further to the west.

And then you have my IGate. It does not digipeat over RF. The only thing it does is listen for packets, and then upload them to the internet.

Ok, it actually does a bit more than just that. I do have a set of repeaters set up to display on aprs.fi and when I go camping and plan on doing long range testing, I usually place markers to help others see where I will be operating from. There are even airport markers that I was testing out awhile back too.
This I-Gate is set to beacon every 30 minutes. I’m not entirely sure if that position is sent out through other digipeaters with an I-Gate or not (pretty sure that’s an option that can be enabled/disabled by each digipeater). Not that it fully matters as it shows up on aprs.fi and likely isn’t of much use to anyone to know where it is anyways, It’s more akin to behind-the-scenes infrastructure than anything else.
The parts:
- Asus EeePC 1000HE (running APRSISCE32)
- Realistic PRO-2037 desktop scanner ($8 in box from a local thrift shop)
- N9TAX SlimJim antenna
- 3.5mm aux cable (audio-out on scanner >>> audio-in on computer)
This setup takes up a bit of space and it could definitely be run on a Raspberry Pi with an SDR dongle instead, but I appreciate keeping old tech alive and running. The laptop is from 15ish years back and is woefully inadequate for running most modern software and the scanner is from sometime in the mid-90’s, but it’s a scanner. It just sits and listens on whatever frequency you point it at, and it just works. The SlimJim antenna is hooked into the BNC port at the rear of the scanner (not pictured) and is currently strung up in a nearby window in a very temporary fashion. A second SlimJim will be arriving in the next few weeks with a 16′ length of coax so that I can hard mount it outside the apartment. That being said, I’ve been blown away by how well the current antenna setup receives packets over the stock telescopic antenna that came with the scanner, even with it being mounted indoors.
Below is a comparison of the receive-capability of the setup from 2 different months in 2024:


At some point in the future I’d like to deploy a full digipeater + I-gate solution, but that’ll have to wait until I can find a decent QTH location much further out from other local digis.














