Transferring pictures with DStar
I’ve successfully experimented with sending pictures using the data portion of D-Star.
I did it in multiple ways, starting with the simplest and ending with the longest path (though not most complex).
Equipment is an Android phone, a Kenwood TH-D74, and an ICom IC-9700.
Simplex
First I did it the simplest way, using simplex between the radios.
You install the ICom RS-MS1A app (sigh, yes that’s the kind of useful naming scheme they have). You’d think this app is needed for the ICom radio, but no. The IC-9700 has Picture mode built in. I used this app for the Kenwood D74.
You start the app, select “Others (Bluetooth)”, and select the D74.
On the D74 you need to:
- Press
1
to go into VFO mode - Select the right frequency
- Set the mode to digital (DV/DR)
- If it’s DR, switch it to DV in the digital menu.
- In the digital menu, switch it to
DATA
Annoyingly, unlike the native picture mode in the IC9700, setting
DATA
mode on the D74 will not allow any voice transmission at all.
On the IC9700, just set the right frequency, switch to DV mode, and
select Picture
from the menu.
I won’t go into detail on how to actually trigger the TX, but it’s pretty simple. It’s better explained by video, and there are some already.
Via my own reflector
This was the most complex setup.
Before annoying people on real repeaters and reflectors with my tests
I wanted it to test it out on my own. I spun up a VM on GCP and set up
a test reflector using these instructions. It was pretty
straightforward except that I had to change /etc/init.d/xlxd
to bind
to 0.0.0.0
instead of the address it picked.
I arbitrarily named my reflector XLX949
, but I would only be
connecting to it by DNS name anyway, so it doesn’t matter.
I used an OpenSpot2 to connect the D74 to this reflector.
On the IC9700 I set it to Terminal Mode
(where it’s just an
expensive interface to the Internet, no RF at all), and connected it
to the VM I’d set up. I got everything rejected until I set my
settings to:
- My station:
2E0VMB
(my Intermediate license call sign) - Gateway callsign:
2E0VMB A
- Your call:
/XLX949B
- R2:
2E0VMB G
- R1:
2E0VMB A
Then it worked, and I could send pictures so that they would go:
IC9700->my reflector->OpenSpot2->D74->Android Phone
By the way, very few reflectors support radios in Terminal Mode (seems only XLX227D and XLX555A,B,C,D). Here are the standard XLX reflector addresses though.
Via a real repeater and reflector
My local repeater was connected to DCS005B
, so I connected my
OpenSpot2 to that too, and put the IC9700 in Normal Mode
.
I could not get the double-speed TX ALL
to work through this. I’m
guessing either the repeater or reflector doesn’t want full data
without voice. So I used the normal Pict TX
, and talked through the
transmission.
Obviously I listened first to make sure I wasn’t interrupting anything, and used small low quality photo settings so that I wouldn’t tie up the reflector and all connected repeaters for too long.
Anyway, this worked right away, and my new path was:
IC9700->My local repeater (GB7OK)->Reflector (DCS005B)->OpenSpot2->D74->Android phone
But why
This means when phone service is down or just doesn’t have coverage I’d be able to send and receive photos. Even using just what I’d have in my pockets. And when phone service is unavailable, that’s when you really want to be able to communicate, to help yourself or others. As long as the nearby D-Star repeater has Internet access, that communication is world wide.