Tag Archives: APRS

A New APRS Gadget

I have had mixed results with APRS in the past. I had been trying to use an old Iphone as the GPS and TNC to feed a Baofeng radio. This seemed to be hit or miss most of the time and the phone is a bit clunky to carry around with the radio. I recently came across a listing on Ebay for “APRS 51TRACK X1C-2 Plug and Play For Radio with GPS +Battery” from China. The device acts as a small GPS enabled TNC that is plug & play with Baofeng HT radios.

s-l500As-l500

I ordered one from Ebay and after about 2 weeks for shipping it arrived. The unit arrived with a cable setup for the Baofeng, a couple of spare RG-11 connectors, A USB to TTL board with a cable set. No manual or instructions were included. I contacted the seller in China and he promptly sent me the manual. It is in Chinese…

…sigh…

No worries as Google Translate did a fairly decent job of translating the text in the files. Charging the unit requires a Micro USB cable. Programming is a one time process that requires the unit to be dissasembled. This is easy enough to do by removing one of the end panels and pulling out the PCB inside. The Li Ion battery sits on top of the board with a small piece of foam in between. To program you will need to connect the USB to TTL board to the PCB using the included cable. Connect the USB board to a PC and it will install itself as a COM port. I struggled a bit with a terminal program (puTTY failed me this time) until i found that a freeware program called Termite did the trick. Once the port is opened (9600,8,1,N) press enter and the device will display its current configuration. Follow the instructions to change to your call sign as well as any other parameters  (SSID or WIDE-1 setting). Once configured, the cable can be removed and the box reassembled. Hook up the radio using the supplied coiled cable. Set the radio to 144.39 Mhz no tone and put it in VOX mode with the volume turned up. press the power button once to turn the APRS unit on. A red light will blink showing the state of the battery charge. The light will then blink blue indicating it is working on a GPS fix. Once the blue light turns solid it will start to beacon position data.

The unit performs as advertised once it is setup. here are the two manual files I receieved modified with English Translations :

APRS Track X1CF 20150501_BH4TDV

APRS Track X1CF 20150501_BH4TDV English

Overall the unit seems to work pretty well once configured and looks to be a decent value. I may add the optional temperature and pressure sensor to it next.

 

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Update on APRS

About a year ago I got APRS working with a Baofeng radio, a Easy Digi interface from N5CEY and a surplus iPhone running PocketPacket. I basically set it up, tested it and put it away.  In December, I put the APRS system back together and nothing seemed to work right. Over several days nothing but frustration. I decided to try this again this afternoon. This time I got it working the first time. Go figure. For future reference things are setup as follows:

Baofeng UV-5R:  VOX=1 volume up about halfway.

PocketPacket: Tracking ON, Report Altitude ON, TX interval 15 minutes, APRS-IS DISABLED, Audio Modem ENABLED, Transmit ENABLED, VOX trigger 500mS, Digipeater path Via 1 = Wide1-1; Via 2 = Wide 2-1.

Iphone volume full.

Next I will look for a way to strap the components together for portable use.

Setup APRS Station

I finally broke down and bought a digital interface from Cliff, N5CEY that connects my Baofeng UV-5R to an iPhone. The iPhone is an older 4S model that is now retired after having been upgraded. It does not connect to a phone service but the WiFi and GPS work fine. I installed the Pocket Packet app and after a bit of fiddling with the radio and the app I started successfully sending APRS packets to the local digipeter.Mission accomplished as I now have a low cost dedicated APRS system to play with.

Vacation projects begin

I am on Christmas/New Years holiday here now and have started some projects I have been meaning to get to. First up was making some short coax patch cables for the portable rig. I also took the opportunity to replace the DC connectors on the amplifier with Anderson Powerpoles and shorten the wiring. I am planning to shorten some of the coax runs on the FT-450D as well so I have plenty of coax connectors on order.

I am also building a interface cable for my iPhone to connect to my Baofeng radio for APRS packet work. I will post on this separately as I start testing it.

I have also ordered two more long whips from Buddipole with the intention of building a portable 2 element yagi to work 20m thru 2m. This will be a mighty interesting experiment. I plan to have everything built up so that I can test when the whips arrive next week.

Last but not least, I am planning to setup the S9v33 vertical as an end fed vertical this week.

Time does fly when you’re having fun!

A couple of new projects to think about…

I have been looking into making a custom air variable capacitor for an improved magnetic loop antenna. This looks like it would be entirely feasible and allow me to make a loop that could handle 100W. At 100W the voltage across the capacitor is just under 3.9kV at 14Mhz. The plate separation for this would be about 55-60mil. It would be a fairly large capacitor but it could be made fairly easily from sheet aluminum.

Just ordered a 2.5mm stereo plug to finish my wiring harness to connect my iPhone to my Baofeng HT to use with APRS. Been wanting to try Pocket Packet app for some time now and this will be my chance.

Also finished making an air choke for the 2m Moxon out of a coax patch cord. This is ready to test out with the new mast.