One feature of many APRS-capable applications and radios is that they support specially-formatted APRS messages called queries or QRU. When the radio receives this message, the text “Q? ” will flash on the top of the screen. Here are the message you can send. ?APRSM – Re-queues any pending messages. ?APRSP – Triggers immediate position […]
Author: David Andrzejewski
OpenTracker USB and Motorola Mobiles
The Argent Data OpenTracker USB is a fully-featured KISS TNC – and it’s one of the least expensive, clocking in at $45 at the time this article was written. If you’re going to build an APRS digipeater or igate, or just use it on your home station in KISS mode, it’s a great solution. Motorola […]
Motorola CDM – No PL/DPL on TX from External Accessory Connector
If you’re trying to interface an external accessory (like a Signalink) to a Motorola CDM via the rear 20-pin connector, and it’s not transmitting PL: Go to “Radio Configuration,” then “Accessory,” then change “Data PTT Audio Source” to “Ext Mic Audio” – if it’s set to “Flat Tx Audio,” the radio will not send PL […]
Debian Jessie: Run aprx as a service
If you’d like to run aprx as a service on Debian Jessie, use this systemd script (in /lib/systemd/system/aprx.service):
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[Unit] Description=Amateur Radio APRS Gateway & Digipeater Documentation=man:aprx(8) [Service] Type=simple ExecStart=/sbin/aprx -i # doesn't do any internal reload # [Install] WantedBy=multi-user.target |
Raspberry Pi: Enabling Watchdog on Raspbian Jessie
If you use a Raspberry Pi, one feature you may not be aware of is that it has a hardware watchdog. When enabled and properly configured, if the system freezes up, the hardware watchdog will reset the system. That’s pretty convenient if you’re putting a Raspberry Pi somewhere remote, like a tower site. Here are […]
Raspberry Pi: Adding a Real-Time Clock on Raspbian Jessie
Updated version of this for Raspbian Stretch here. The Raspberry Pi is a great computing device at a great price – but to keep costs down, sacrifices had to be made. One of those sacrifices was a so-called “real-time clock” or RTC. Without one, the device forgets the time as soon as it’s powered down […]
Tytera MD-380 – Enable test/alignment mode
If you have a Tytera MD-380 and would like to perform some alignment on it, you can enable “test mode” in the CPS.
A quick and unscientific spectral analysis of two Baofeng radios.
I tested a couple of Baofeng handheld for compliance with FCC Part 97’s spectral purity requirements.
Allstar Permanent Node Connection
Here’s how to ensure your Allstar node maintains a permanent connection to another node.
