Category Archives: APRS

APRS to SMS Gateway

Did you know you can send/receive messages from APRS to the SMS network? Super easy.

Just compose a message to:


Start the message with @(the destination phone number) (space) (short message). Example, if I want to send the message “test” to phone # 123-456-7890, then the message will be:

@1234567890 test

SMS users can reply, as long as you are still within range of the digi that heard your beacon.

Easy Digi PTT Settings IC-2300

I use an Easy Digi interface between my Icom IC-2300, Direwolf & APRX. Here is my PTT string for my direwolf.conf file for Push To Talk:

DEVICE  plughw:1,0


MODEM 1200

PTT /dev/ttyUSB0 DTR RTS


LOGDIR  /var/log/direwolf/

APRS in the Treasure Valley (Boise, Meridian, Nampa, Eagle)(2019)

Boise APRS Coverage Overview

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SHAFER provides reliable coverage along I-84 from Mountain Home to Ontario, OR. To the south, most of the valley including the northern face of the Owyhees. And to the north, sporadic coverage in the mountains and along Hwy 55 to Horseshoe Bend.

Near Cascade, SNOBNK provides broken coverage in the Boise mountain range and along Hwy 55 from Smith’s Ferry to McCall. To the west, it covers I-84 in Oregon as far as Ontario.

In the Boise area, MERIDN Fill-in digi provides coverage along the foothills and in town. MERIDN IGates all traffic, but only digipeats over the air if MERIDN hears it direct *AND* mountaintop digi’s don’t digipeat the beacon (using APRX’s “viscous-delay” feature, set to 5 seconds). This prevents MERIDN from adding noise unnecessarily.

CNABAR, previously in the Owyhees to the south, will hopefully return at some point to provide coverage down Hwy 95 and into eastern Oregon.

Recommended Path Settings

For Handheld Radios (HTs)
WIDE 1-1,WIDE 2-1
The first path is for fill-in digi’s. The second path is for mountain-top digi’s. Central and southern Idaho has enough IGates and wide coverage that one mountain-top beacon is usually sufficient to get your packet to the Internet.

For Mobile Operators
WIDE 1-1,WIDE2-1
Same as HTs, this will get you beaconed by fill-ins, plus one hop from mountain tops, which will usually get you gated to the Internet. If you use WIDE2-2 in the Treasure valley, your beacon will likely hit SHAFER, then SNOBNK (into McCall) and BKRCTY (into La Grande). If you need direct receipt of your packets that far away, just realize you are lighting up several mountain digi’s to accomplish that.

For Base Stations
WIDE 2-1
If you are beaconing from a fixed location in the Treasure Valley within earshot of SHAFER, I recommend using the path WIDE2-1. No fill-in digi path needed. One hop from SHAFER will certainly get you IGated.

For High Altitude Balloons
(Don’t specify a path)
If your beacon will originate higher than ~10k ft, then you don’t really need any digipeater path in your config. It will be heard by multiple IGates and routed to the Internet. If you are (rightfully) concerned about when it drops below average terrain, then see if your tracker has the feature to change the path based on altitude.

At MERIDN, I have elected to IGate all balloon packets, but not digipeat them. On multiple occasions, balloons have passed over at 70k ft using a WIDE2-2 path every 30 seconds and as a result have caused congestion for hundreds of miles. With that altitude, they can be heard from Vancover to Vegas to Salt Lake City.

A Note to Fill-in Digipeater Operators & Tinkerers

Thanks for providing this service. The SHAFER digi has good coverage for most of the valley, but much of the foothills are in its shadow. Users on the southwest side of the Boise mountain range need help getting their signal out. However, for a long-term configuration, I recommend you use the “viscous-delay” feature from APRX so you aren’t repeating packets already beaconed from SHAFER or other digi’s. As an alternative, if you’re using Direwolf, you can set it to only digipeat WIDE1-1 packets.

Hiking/Biking Considerations

I often hike & bike near Boise with my HT set to beacon. Sadly, in my experience, 5 watts is not sufficient for most packets to get IGated, even if you feel like you can see the mountaintop digi for most of the outing. Yes, some get through, but I wouldn’t count on much of your journey getting tracked. Anecdotally, it seems better to just stop near a summit, do a manual beacon and listen for your repeated beacon to be sure something went out.

Kenwood TH-D74 Battery Life Using APRS

I recently bought a Kenwood TH-D74 for hiking and APRS use. I had seen anecdotal complaints about the battery life around the web, but had not seen any real world data. So I setup a test and timed the battery performance.

I started with a fully-charged, stock 1800mAh battery.


  • Both bands enabled
  • A Band set to 146.52
  • B Band set to APRS
  • Both Bands on HIGH power (photo was taken later)
  • Beacon set to Auto, every 10 minutes
  • Did not transmit on A (voice) band at all
  • Bluetooth set to OFF
  • Backlight set to OFF. Well, actually MANUAL (was turned on a total of 15 seconds to check battery levels throughout the day)
  • GPS power set to Auto
  • Very few (if any) beacons received
  • Firmware 1.06

In short, nothing major was draining the battery other than the APRS beacon.

Result: 8 hours

Mag Mount vs Drilled Hole (NMO) for APRS

I’m always looking for better APRS coverage.

I’ve had a Tram mag mount on my 2014 Subaru Forester for two years. Of course, everyone recommends drilling a hole in your roof instead. Most everyone claims they can hit repeaters they’ve never been able to hear after permanently mounting their antenna. I don’t doubt their claims, but my experience for APRS is slightly different. My hope was, after changing from the mag mount to the drilled hole, many APRS dead spots would be reduced or eliminated. Read on for the details.

The old setup:

  • Tram 3″ Mag Mount
  • 1/4 Wave (19″) 2M Antenna
  • Placed on the very back of the roof, centered
  • Yaesu FTM-350 Radio


The Measurements

I operate a Fill-in digipeater near Boise, Idaho, so I am using that as my reference point.

  1. I can clearly see where my packets are heard via to compare before and after.
  2. Better still, I know from considerable experimenting, where the dead spots are in my area.
  3. But, it is worth noting that APRS packets are more picky and less forgiving than a voice QSO.

DIY vs. Paying A Pro

I strongly considered drilling the hole myself. There are lots of tutorial videos on YouTube that show you how. I would either need to remove the entire headliner, or figure out how to snake the cable half-way up the vehicle, bypassing a large sliding sunroof. After about 8 hours of research over several months, I decided to pay my local two-way radio shop to do it for me.

  • Cost: $85 (for materials and labor)

Initial Results

After about 24 hours of testing, I can only see about a ~10% improvement. One area that is normally sketchy received a solid beacon. The other 8 or 9 areas are no different than normal. These are not far-away places… just sections of town that might be slightly lower or obscured in some way.

Next Test…

Replacing the 1/4 wave with a 5/8 wave with higher gain.