Ultra Portable HF APRS SMS kit for the back country

[pcunite]

I'm looking to acquire or somehow build an ultra portable HF sms text messaging radio for when I'm out in the back country. I only need to transmit to the nearest iGate to send the APRS SMS text message. The radio will be stowed away in a backpack and only used to check-in back home once a day or so.

Requirements:

• Battery powered (prefer 18650).
• 6M and/or 10M band compatible.
• Mobile phone interface to run JS8Call or similar utility.
• Small and light weight.
• Only Data digital mode will be utilized, no need for voice.

The (tr)uSDX, FX-4CR, and QDX look interesting. Is there a product or packaged solution that meets all my requirements? Anyone else want a setup like this? Most of the options I see in this space use a windows computer or laptop. However, I want to keep things very light and utilize the phone I already have on me.

I know options exists for VHF, but I need the propagation of HF bands.

 

[prcguy]

How far is your "back country" from the nearest iGate? A portable low power 10m or 6m radio will not go very far. And you would need a good antenna up high to make the most of the low power.

 

[pcunite]

I need about 100 miles. The issue is I'm down in valleys about 2,000 feet deep, but could climb high enough in 30 minutes to send out a message. I was wanting the ability to get over the moutain tops if I could.

 

[prcguy]

10m and 6m from a portable setup might go 5mi if your lucky, I would target 40m during the day and 80m at night using a low horizontal wire antenna for NVIS propagation.

I need about 100 miles. The issue is I'm down in valleys about 2,000 feet deep, but could climb high enough in 30 minutes to send out a message. I was wanting the ability to get over the moutain tops if I could.

 

[mmckenna]

Is there a product or packaged solution that meets all my requirements?

Not ham radio, but there are solutions that will do exactly what you want via satellite.

I carry a Garmin InReach Mini with me when I'm out in the sticks. I have a ham license, I also am usually working on remote LMR radio sites, so I already have a two way radio.

The InReach products run through a satellite, so as long as you have a view of the sky, you'll get through. Subscription plan runs about $11/month and you can shut it off/turn it on as needed. You can send/receive text messages to whomever you want, as well as trigger an SOS that will get to a trained professional, not a hobbyist.

Weighs a few ounces and will connect to your cell phone to allow mapping, texting, weather reports, sending tracks/positions to others, as well as triggering SOS messages.

 

[AK9R]

I'm looking to acquire or somehow build an ultra portable HF sms text messaging radio for when I'm out in the back country. I only need to transmit to the nearest iGate to send the APRS SMS text message.

Most APRS I-gates operate on VHF. I don't think an HF-only solution will help you reach nearby I-gates.

 

[n2nov]

Most APRS I-gates operate on VHF. I don't think an HF-only solution will help you reach nearby I-gates.

The question then is, are there any APRS iGates running on 80, 40 or 30 meters? This would help the NVIS requirement from a valley to reach out 100 miles.

 

[n2nov]

The question then is, are there any APRS iGates running on 80, 40 or 30 meters? This would help the NVIS requirement from a valley to reach out 100 miles.

I know, I am replying to my own posting.
Go to Groups.IO and find the APRSISCE forum.
Plenty of chatter there about HF and APRS iGates.

 

[AK9R]

I'm not saying that APRS I-gates don't exist on HF. I am saying that the likelyhood of being able to reliably reach one from the "back country" with a portable radio/antenna is slim.

mmckenna's answer in post #5 is the best solution IMHO.

 

[pcunite]

The InReach products run through a satellite, so as long as you have a view of the sky, you'll get through.

Thank you. You are correct, and that is a very good answer. However, this is an amateur radio forum, so I'm also wanting an HF radio option, if possible.

 

[popnokick]

I need about 100 miles. The issue is I'm down in valleys about 2,000 feet deep, but could climb high enough in 30 minutes to send out a message. I was wanting the ability to get over the moutain tops if I could.

Since you wrote in your other message you are looking for an HF backpack portable solution search for info on SOTA (Summits On The Air) and the setups they are using that can be backpacked to a summit. There are many hams doing this on a regular basis with some clever equipment setups. Definitely not for life safety (use satellite systems for that as previously described)… but HF backpacking is really the standard SOTA setup.

 

[pcunite]

So, this antenna (Par EndFedz EFT-102040 Trail-Friendly) is small and light enough to carry. I can suspend it on trees. That gives me 40M NVIS range (100 miles) to be able to hit an HF iGate? I'm only sending data (APRS SMS) so it can be a somewhat non-optimal configuration.

I need to figure out the radio and phone interface.

 

[prcguy]

You can make a better version of that antenna for about $20 and it will roll up inside a plastic chalk line reel for quick deployment. Not to mention it will be more efficient at an actual half wavelength long on 40m or about 64ft.

So, this antenna (Par EndFedz EFT-102040 Trail-Friendly) is small and light enough to carry. I can suspend it on trees. That gives me 40M NVIS range (100 miles) to be able to hit an HF iGate? I'm only sending data (APRS SMS) so it can be a somewhat non-optimal configuration.

I need to figure out the radio and phone interface.

 

[n5ims]

You might also want to check out Winlink to see if that will suit your needs. Winlink traffic is more like e-mail than SMS but you're probably more likely to find an HF Winlink gateway than an HF APRS iGate. Also Winlink can send to not only Winlink addresses, but also standard e-mail addresses (if the selected gateway allows). As with APRS, Winlink is typically a VHF/UHF operation, but Winlink has specific HF related operation modes and these modes are designed for emergency communications (generally from marine traffic, but not restricted to that). Using either method, you should prepare for whatever you select and locate appropriate gateways or iGates that might service your planned area. Specifically verify the bands/frequencies used, protocols (standard packet, VARA, Pactor, etc.) and times that they're available (some rotate bands on a schedule say 40 mtrs top-of-the-hour to 10 after, 20 mtrs 10 after to 20 after, 15 mtrs 20 after to 30 after and repeats from there and between certain times, they swap 80 mtrs for 15 mtrs - this is only one example, there are many).

 

[AK9R]

You might also want to check out Winlink to see if that will suit your needs.

You can also use Winlink to send position reports.

 

[krokus]

You might also want to check out Winlink to see if that will suit your needs. Winlink traffic is more like e-mail than SMS but you're probably more likely to find an HF Winlink gateway than an HF APRS iGate. Also Winlink can send to not only Winlink addresses, but also standard e-mail addresses (if the selected gateway allows).

Most cellular providers have an email gateway to their SMS servers, at least in the US.

 

[KI6ESH]

My plan currently is the QDX, a Raspberry Pi 4 running Build-A-Pi, a Par EndFedz EFT-10/20/40 antenna, all likely running from a portable power bank such as a Mini UPS Battery Backup. Then I'll simply connect to the Pi via VNC (screen share) from my phone or tablet and run JS8CALL, which can easily relay messages to the APRS-IS network. Using JS8CALL I can easily send SMS text messages to any phone, position reports, emails to internet email addresses, retrieve weather reports or even send Tweets.

I love VHF APRS, but there just simply aren't enough digipeaters or iGates in the places I am usually hiking, and via HF even on 5-watts I can regularly reach Europe from Oregon.

 

[pcunite]

@KI6ESH,

Thank you! I'm trying to put together the exact same thing.