As is often the case, my dad sent me a text message as I was sitting around with my radio and put an idea in my head. It was a fairly simple idea and he was just trying to be helpful. But there went 90 minutes of poking at various bits of tech.
I’ve been really, really into WSJT-X FT8 lately and have managed to get 49 states and a pile of countries using it in a pretty casual way on 20m and 40m. I hadn’t thought much about running it in the field until last weekend. I was out with the Jeep and used it as a mobile station. That’s an IC-7100 with a MP1 Super Antenna mounted to the back of the Jeep. The Jeep was not in motion, mind you, but sitting in a parking lot. That antenna has been great for me, but it’s not a whip. It wasn’t the best location for field operation, but it was still disheartening to hear only a few signals and not be able to get out on HF.
I contrast this with my FT8 experience every day of being able to hit stations in Europe or South America at -24dB. So the thought of taking my laptop out into the field for some operation was bubbling a bit in the back of my mind.
Serious side note: As far as a laptop is concerned, I have a WinBook that you can only get at MicroCenter. It’s a very low power, very lightweight combination tablet/laptop that can charge on 5v. It isn’t particularly rugged, but at a $100 price point, it’s just what I needed for the simple computing I do with my radios.
One of the concerns with FT8 is making sure that your clock is sync’d. Being out of sync results in incomplete contacts or missing potential contacts altogether. Which takes us back to my dad.
He was poking around for a GPS unit to keep his laptop in sync with a good clock. What’s really easy to do with a network connection at the shack can be a real challenge in the field. So he grabbed a unit, downloaded GPS2Time by VK4ADC and managed to sync his laptop via GPS.
As I prepared to copy him and toss that dongle into the shopping cart, my TH-D74A that was sitting next to me buzzed to life with the evening Net run by K3PDR (The Philadelphia Digital Radio Association) on D-STAR Reflector 020A Monday nights at 8 PM Eastern U.S. I looked at my radio and having recently been noodling with APRS (post on that coming soon) I wondered if I could just use the GPS from that radio.
And yes. Yes I can.
A couple of thoughts. I have confirmed that if you don’t use a USB 2.0 cable to connect the HT to the computer, it will confuse the computer and not work. I have also confirmed that while Bluetooth is not good for syncing programming data with the radio (unless you have some time – or really a LOT of time) it is more than acceptable for transferring GPS data.
There are two approaches to GPS on the TH-D74A. The first is to put the HT into GPS only mode and the other is to leave it in Normal mode. Both work for this application.
The steps to make this work are simple:
- Connect the TH-D74A to the computer via Bluetooth. This will depend on your OS and version of that OS. On Windows 10 it’s relatively trivial to pair them and I was fortunate that it worked on the first try.
- Navigate to Configuration -> GPS -> Basic Settings -> Built-in GPS and set it to ON.
- Navigate to Configuration -> GPS -> Basic Settings -> PC Output and set it to ON.
- Run GPS2Time on your Windows Computer AS ADMINISTRATOR (that bit is critical).
- Select the COM port associated with the HT in GPS2Time and hit the RUN button.
That last step there? It’s important. It will take a minute. I recommend making sure you have a GPS signal before you kick this off. If you have acquired a position, this will go much more quickly. The time will be set according to the satellites and the goal is achieved.
I feel like this is a great solution to my “problem” as I always have the HT with me in the field and with a Bluetooth connection, though it does eat battery, there isn’t a missing cable in the field or the frustration that comes with swapping things around while you’re trying to work with a limited timeframe. It’s also handy that in my case, the radio and the computer can be charged via the Jeep without any special considerations.