Category Archives: Digital Communications

Accessing AllStarLink from a SIP telephone

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I have been using a SHARI AllStarLink node for some time as a means to tinker and learn about AllStarLink (ASL) and to explore the wide web of nodes around the globe that are connected to this vast network. ASL (HamVoIP being the flavor of it on my node) is based on Asterisk, an open source PBX system that is capable of handling the most complex telephony tasks and could conceivably be used to replicate or even replace nearly all voice switching capabilities of the public switched telephone network. On the K6TZ repeater system, we have configured the repeater node to handle phone patch requests over VoIP, eliminating the need for a copper line to offer radio to telephone network connectivity. This means that members can key in a code followed by a phone number on the 446.400 repeater to initiate a phone call to any number in the USA. I had also heard that ASL could provide for direct access to radio linking through SIP connections, sort of a reverse autopatch, whereby one could dial into the node from a SIP telephone to access and link to nodes throughout the ASL network. In setting out to configure my own SHARI node for this, I ran across a few inconsistencies on how to accomplish this so I am writing up this article to document what worked for me. The first place I turned was the official ASL wiki documentation. It is helpful but somewhat incomplete in its explanation. Below I’ll outline the steps and try to explain them in a bit more detail, adding some additional configuration to support multiple SIP extensions. The first step is to locate and edit the /etc/asterisk/modules.conf file. I am including the full path to all files since it can be challenging for newbies and experienced users alike to find them, especially when tinkering in ASL is not a daily task. We must edit the modules.conf to be sure the SIP module is loaded by ensuring that the following line is present: load => chan_sip.so ; Session Initiation Protocol (SIP) You may see this line in your file beginning with noload. Simple change it to load and save the file. Next locate the /etc/asterisk/sip.conf file and open it in your favorite editor. In this file we will append the following code to add one new SIP extension to our node. Note that I am calling… Continue reading →

K6LCM LiFePO4 PowerBank Battery Box

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I experienced some disappointing results with a portable 12-volt jump-start lead-acid battery at Field Day this year. David, AC9AC, saved Field Day for me by bringing by his 30 amp-hour LiFePO4 battery to our operating location at Shoreline Park. Impressed with its capabilities, I decided to upgrade my portable power. There are a number of vendors on Amazon and Ebay selling high-capacity LiFePO4 batteries at low prices. LiFePO4 batteries are impressive. Without going into too much detail, the main advantages are that they are up to 70% lighter than lead acid batteries, will continuously supply 13-14 volts under high-current draw conditions and can be completely discharged without damage. Most LiFePO4 batteries include a battery management system inside the sealed plastic battery itself, making them nearly a drop-in replacement for lead-acid applications. In fact, many new 12-volt chargers include special modes for optimally charging LiFePO4 cells. If you search online, you’ll find many pre-made power stations. The problem is that most of them are designed with general consumers in mind. Your average power-hungry electronics guru mostly needs a 5-volt USB power connection and a 120-volt AC outlet. These premade power stations typically lack higher current connections such as Anderson Powerpole sockets. The designers of these pre-made power stations were probably thinking: “Who would want to draw 20 amps at 12 volts?” Hams would of course! My requirements when designing the K6LCM PowerBank were that it would support typical 5-volt USB connections and a 12-volt DC cigarette lighter connection for running mobile chargers. But my design added two 12-volt DC Anderson Powerpole connections for supplying up to 20 amps of current for higher draw devices like HF rigs. Below are some photos of the build and a parts list. I mounted the binding posts inside the top compartment of the Harbor Freight ammo box as shown. Using 12 AWG wire, I connected the battery itself (using the blade fuse connector with a 20-amp fuse) and all of the power outlets to the positive and negative posts respectively. In addition to the fuse, the positive battery lead passes through the master switch on its way to the positive binding post. The only connection that does not pass through a binding post is the positive (7.5-amp fused) connection between the charging port on the back and the battery. Since I intend to use this setup as portable power, I won’t be running the charger… Continue reading →

FM Simplex Node Frequencies in Santa Barbara

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  Over the past few months there has been a renewed interest in AllStarLink FM simplex nodes among our members. These low power devices allow users to connect to remote VoIP nodes and repeater systems using an internet connection and an HT. Most opt to buy or build a device on 70cm. A couple years ago, during the initial DMR hotspot craze, SBARC expert consultant Matt W6XC identified a few frequencies around 431 MHz that were useful for digital hotspots like the OpenSpot and ZumSpot. HOWEVER, these frequencies are NOT appropriate for analog FM nodes. We must use a different part of the 70cm band for FM emissions. Matt suggests the following options for low-power, analog FM usage: 440.000/445.000; 446.860/441.860; 446.880/441.880 may be used as pairs for a low-power duplex node or as separate simplex node frequencies. Please listen to these frequencies with low squelch settings and no CTCSS for a few days before permanently parking your node here to see if and how these frequencies are used. FM simplex nodes are best PL/CTCSS protected, especially if they are left connected to a system like K6TZ or WIN System. Definitely avoid 446.000 altogether. This is the National Calling Frequency for 70cm. 446.500 and 446.520 are “General Simplex” frequencies. Others many want to use these for simplex QSOs or other itinerant purposes so please don’t park your node on any of these three frequencies. Also note that 432.000-439.999 MHz is allocated to weak signal, Amateur Television and digital emissions only. 440 is tough given the lack of simplex allocations. It’s a truly stuffed band! Perhaps just as important as which frequency you choose for your node is setting the PL/CTCSS tones. In Santa Barbara and Ventura counties, DO NOT use 131.8 or 88.5 127.9 or 131.8 Hz as a tone for your node. Picking almost anything else will ensure that you don’t inadvertently open the receiver of a repeater on the same or nearby frequency. If you are interested in these FM VoIP nodes, consider the ClearNode and SHARI projects.   Levi, K6LCM K6TZ Trustee

November General Club Meeting: Tracking Transpacific Airliners

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 0:00 Pre-meeting chatter 26:30 Meeting Start and Intros 53:30 Tracking Transpacific Airliners Presentation Start 1:27:10 Questions & Answers Meeting Presentation Slides (pdf) Our November Club Meeting was host to our Board of Directors election as well as a presentation by Levi C. Maaia – K6LCM on using your ham equipment and/or computer or smartphone to listen in on transpacific airline traffic on the VHF and HF bands. Hams aren’t the only ones using HF on a daily basis for reliable, long-distance communications. Airline pilots use HF frequencies from 2800 kHz to 22 MHz as their primary means of communication with shore stations during oceanic flights. These comms can be received by anyone with an HF SSB tuner and provide interesting data points for HF propagation. Aircraft are even sending PSK over HF! Levi showed us a tracking demonstration of a flight from Los Angeles (LAX) to Sydney (SYD) as well as pointed us toward some resources for tracking and listening in on our own, with or without a radio!

DMR QSOs from your Android

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I just tried out a cool app for Android users … DROID-Star lets users login to the Brandmeister DMR system using your DMR ID and presents an interface that is operationally similar to Echolink. You can connect to any TG and then use the on-screen PTT to have a QSO. Works decently well for a beta version. Despite the “D-Star” branding it is a DMR app. Haven’t figure that part out. Download it from the Google Play App Store. -Levi, K6LCM

Yaesu System Fusion-DMR (YSF2DMR) Cross-Mode Repeater

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Over the past two years, there has been an explosion of interest in DMR amateur radio. Many SBARC members have been bitten by the DMR bug and they are chatting around the world on global Brandmeister talkgroups using hotspots and repeaters. While much of the attraction of DMR is the ability to work DX on a handheld transceiver, many local operators hang out on the local SBARC Brandmeister DMR Talkgroup (TG 31073).  In fact, every Tuesday night, the Digital Communications and Technology Net moves from 2m FM to TG 31073 at 21:00 Pacific Time. If you aren’t on the air with DMR yet, not to worry.  You may be able to chat on TG 31073 with a radio you already own! K6TZ operates a multimode digital repeater at La Vigia on the Mesa in Santa Barbara. We have recently reconfigured this repeater to bridge traffic from Yaesu System Fusion radios to TG 31073 using a new protocol called YSF2DMR. If you have a newer Yaesu radio, you may be digital-ready right now. Many new Yaesu amateur radio models available support System Fusion and are capable of connecting to the K6TZ digital repeater in order to bridge from System Fusion to DMR and TG 31073. Joining the local digital chatter on TG 31073 via System Fusion on the Santa Barbara South Coast is fairly straightforward. Just follow these steps: Obtain a DMR ID. If you have not already, click here to register your callsign with the DMR network and receive a unique DMR ID number. Your DMR ID is paired to your callsign on the DMR system and used to identify your transmissions. It takes a day or so to get a new DMR ID assigned and you only need to register once. Once you receive the confirmation email, keep it. You won’t need the number now using System Fusion but if you get bitten by the DMR bug in the future and want to explore further you will use this same DMR ID to configure a DMR radio. Set your amateur radio callsign in your System Fusion radio. Each radio model handles this differently. You must enter into your Yause radio the exact same callsign you registered to your DMR ID. The SBARC repeater will only bridge properly identified transmissions from System Fusion to DMR. So be sure you have input your callsign correctly and that you have received confirmation of… Continue reading →

General Club Meeting – February 15, 2019

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Last August our topic was DMR radio. Since then I have had a lot of requests for another DMR presentation, and since some new capabilities have become available, I thought this would be a good time. A lot of members have purchased DMR radios and would like to know more about their use and capabilities. A lot of our members have also purchased and Yaesu System Fusion radios as well. In fact, the Yaesu FTM400 mobile radio is probably the most popular general mobile radio in the Santa Barbara Area. There are probably 20 or more SBARC members with these radios but only use them for regular FM. Yaesu YSF radios are digital capable, but use a different digital protocol. Now it is easy to use your Yaesu YSF capable radios to communicate on DMR on the SBARC or other favorite talkgroup. At this meeting, we’ll show you how and do some demonstrations. So bring your DMR radios and Yaesu YSF HT’s if you have one. And, bring your questions about this or DMR in general. SBARC is lucky enough to have their own dedicated talkgroup, and we need to utilize it more. With this new capability, hopefully we can get more members to come over and give digital a try.   SBARC General Club Meeting Friday, September 21, 2018 at 7:30 PM Goleta Union School District Board Room 401 North Fairview Avenue in Goleta We hope to see you all at the meeting! Post expires at 11:00pm on Friday February 15th, 2019 but will still be available in the archives.