Category Archives: Digital Communications

Amateur Videos on Amateur Radio: YouTube

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In recent years, there has been a notable shift in the landscape of amateur radio journalism. Traditional print magazines and journals, once the cornerstone of the ham radio community, are increasingly becoming a rarity. This decline is part of a broader trend seen across many fields, where digital media is supplanting print media. As a result, much of the latest news, technological updates, and exciting new projects in the amateur radio world are moving to more contemporary platforms like YouTube. This shift has given rise to a number of popular YouTube channels that have become the new go-to sources for amateur radio enthusiasts. These channels offer a diverse range of content, from in-depth tutorials and product reviews to real-world applications and community interactions. Here is a list of some prominent YouTube channels that are leading this digital transformation in amateur radio journalism. If you have others you like, please leave them in the comments! Ham Radio Crash Course: Basics to advanced ham radio topics, tutorials, reviews, and discussions. Ham Radio 2.0: Product reviews, interviews, event coverage. KB9VBR Antennas: Antenna performance improvement, DIY projects, tips. K8MRD Radio Stuff: Educational content, real-life ham radio experiences. HamRadioConcepts: Equipment reviews, tutorials, experiments. Temporarily Offline: Mix of educational content and personal experiences. K0PIR: Software, hardware, digital modes in ham radio. Ham Radio DX: Reviews, tutorials, interviews, propagation and DXing. Dave Casler KE0OG: Educational content on amateur radio topics. KM4ACK: Ham radio technology, DIY builds, software solutions and RaspberryPi projects.

New Packet Capabilities at TCF

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We have just installed a new VHF packet node at the Talanian Communications Facility on the Mesa. The new station has a Winlink gateway that can gate mail between RF and the internet (perfect for emergencies), as well as a few other features, including a local keyboard chat room! Check it out if you have a TNC or sound card modem for VHF packet on 145.050. The main node is K6TZ-2 but the following aliases will connect you directly to the various services: MESA (main node), TZPBBS, TZCHAT, TZRMS (Winlink) Note that BPQ is a little different than Kantronics. Commands like MHEARD and CONNECT (to hop) require a port number (in this case the port number to use is 2). More details in the welcome message. Thanks to Doc, W6EW for donating the Kenwood TM-D700 to the club and to Bill, W1UUQ for leaping into action when I said I needed help tracing out the coax at his namesake TCF. This is the first of a couple major planned packet upgrades. We expect to install an updated digipeater at the La Cumbre West Site in the coming weeks which will expand the reach of this node. If you are interested in learning more about VHF packet radio and other digital modes, join us on Tuesday nights for the Digital Communications & Technology Net and consider joining our group mailing list. -Levi, K6LCM K6TZ Trustee

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