Sunday, October 6, 2019

-APRS applications

Overlooking Anchorage, Alaska 3510 ft ASL

On the way up/down some location beacons were not recorded. APRS tracking is limited to where you can be heard by an igate or repeater.  On VHF this is basically line of sight to town.

Sunday, April 28, 2019

-Install/upgrade external antennas, coax into house, & ground system.

Installed lightning rod to power grill Back to the Future style.

-2x galvanized conduit (1 & 1.25" EMT) + hose clamps.  Arrow OSJ 146/440 now @ ~30 ft HAAT.

Sunday, March 24, 2019

-Raspberry Pi 3 and Mobilinkd TNC2 for APRS duty

  • Setup Xastir on Raspbian to act as an Igate using Mobilinkd KISS TNC.

Xastir doing RF -> inet gating.  Terminal highlights commands to activate Bluetooth serial link after paired to Mobilinkd.

Sunday, March 17, 2019

-12 Vdc power

Current home setup for powering radio equipment:

Electrical hardware mounted on a cutting board.  Samlex SEC-1230UL 30-A charger, Optima Blue Top 55-Ah battery.

  • The SEC-1230UL is a switch mode supply but quiet enough to not interfere with HF reception.  
  • With the SEC-1230UL and a battery, the system behaves as a dc Uninterruptible Power Supply.
  • With 120 Vac available, the system can maintain a <30 A draw indefinitely (limited by the charger).  However, higher amperages can be sustained intermittently (limited by the battery).

Monday, March 11, 2019


New Mobilinkd TNC 2.2 . Working well so far.  Very quick to setup.  
It links to a tablet, phone, or computer (via Bluetooth) and a radio (via cable).  

The Mobilinkd is a KISS TNC.  It MOdulates/DEModulates between the radio audio in/out and a digital signal sent over the Bluetooth-serial link while facilitating switching of the radio PTT.

The end functionality is completely dependent upon software.  One of the most common uses is for APRS:

Mobilinkd TNC 2.2 w/ Baofeng UV-3R and APRSdroid on a tablet.
The high resolution screen is ideal for mapping APRS data.

The radio and TNC are a compact package.
The Bluetooth is nice as the tablet is not constrained by a physical link to the TNC.

Sunday, February 10, 2019

-DMR hotspot operational

TP-Link TL-WR802N and SharkRF openSPOT 1

Local digital radio internet gateway. 20 mW max output (UHF)

(radio) <-> (openSPOT) <-> (worldwide DMR networks via internet)

-APRS troubleshooting

Anytone AT-D878UV: garbled coordinate data in APRS position transmission causing it to be ignored by receiving stations.

A second example showing other stations' APRS traffic for comparison

Update 2/27: Found some information here leading me to a solution for the APRS issue.  Below is a screenshot of my 878 APRS settings which have resolved the unintelligible transmission problem:

Take note of the time delay settings (with red dots) as well as the lack of a coma in "APRS signal path".  These changes resulted in my APRS transmissions clearing up and finally showing up on