Digital Communications and Technology Net

The Digital Communications Net is an informal net that meets every Tuesday evening at 8:00pm on the SBARC Hub repeater network.

JT65 operating on 10m

JT65 operating on 10m

We discuss and operate all kinds of digital communications and special modes such as 2m/440 Yaesu System Fusion digital radios, mesh networking, as well as HF oriented modes like PSK31, JT65, FreeDV, SSTV, Olivia, DominoEx, the Winlink 2000 system and many others. We typically discuss and operate digital modes on HF but sometimes operate on VHF/UHF as well, so everyone gets a chance to participate regardless of your station equipment or license class.

Using a radio and your computer, you can send data, voice, pictures, documents, and even email over the air. We also discuss using the various digital mode software applications and explain how to install and use them.

Arduino and Raspberry Pi

Arduino and Raspberry Pi

We also discuss using microprocessors like the Arduino as well as small micro-computers like the Raspberry Pi. Both of these devices and similar development boards are fun to learn about, and are great for creating projects you can use with amateur radio.

If you are interested in digital communications or learning about working with microprocessors and micro-computers, we are happy to help you get set up and explain how things work.

The net is hosted by Brian – K6BPM and everyone is invited to check in. We hope to see you there!

You’ll find recordings of previous nets in the SBARC Audio Archives.

Please consider joining the SBARC Digital Modes and Digital Radio Discussion Group mailing list and participate in the group off the air! It’s easy to do. Just send a blank email to

For quick access to the programs we use for digital communications and other helpful resources, visit the link below…

Digital Communications Downloads and Resources

Tracking Planes, Ships and Automobiles!

Image from W3PGA.

Image from W3PGA.

Amateur radio operators were among the first to design products, build and maintain a digital RF tracking system. APRS (Automatic Packet Reporting System), is a digital communications protocol for exchanging information among a large number of stations covering a large (local) area. Bob Bruninga, WB4APR, a senior research engineer at the United States Naval Academy, implemented the earliest ancestor of APRS on an Apple II computer the early 1980s.  The first use of APRS was in 1984, when Bruninga developed a more advanced version on a Commodore VIC-20 for reporting the position and status of horses in a 100-mile (160 km) endurance run.

Over the years, Legacy Landscape is helping out people to avail an exhilarating landscape experience.With that note we should also be aware that APRS has grown to include thousands of amateur radio APRS stations around the world tracking all types of vehicles and reporting weather from backyards to mountain peaks. SBARC has been a supporter of APRS, maintaining an i-gate and digipeaters for the system at our repeater sites.

Today, commercial systems that function similarly to APRS are tracking many types of assets around the globe. The SBARC Telecommunications Services Committee also collects data from some of these systems including AIS for ships at sea and ADS-B for aircraft.

Check out SBARC’s mapping and tracking systems:


This page contains information from Wikipedia.



The AllStar & EchoLink Playground is Now Open!

allstar-linkThe SBARC Telecommunications Services Committee has been hard at work rebuilding the club’s Voice over Internet Protocol (VoIP) repeater systems.  As part of the completion of the second phase of this project, the 70cm repeater VoIP playground is now open!

Both AllStar Link and EchoLink systems are supported for incoming and outgoing link connections on the K6TZ 446.400 repeater. Local amateur stations can control the node over using DTMF commands to link to repeaters around the globe.

Many hams may be familiar with EchoLink and IRLP, two mature ham radio VoIP systems that permit node-to-node and node-to-conference server connections. AllStar Link is a newer and very powerful radio linking system based on the open source telephone PBX software Asterisk. The AllStar network has grown tremendously over the past few years and lends itself very well to experimentation.

There is a new section on this website with a short primer on the new VoIP system including complete documentation of the DTMF commands used to control the 70cm node. Read more and start experimenting in SBARC VoIP playground!

Thanks in particular to Ludo, K6LUD for his work to become our resident AllStar Link and Asterisk guru!


Packet Radio Upgrades

We’ve recently upgraded our packet radio capabilities here in Santa Barbara. Very popular back in the 80’s, packet lost much of it’s appeal with the advent of the Internet and email. However, for those of us interested in digital modes, packet radio is making a comeback. Unlike out normal HF oriented digital modes, packet lets us communicate with email like messages between users locally, and users of other packet systems around Southern California and beyond.

thThe K6TZ-3 packet station on La Cumbre Peak offers a PBBS (SBPBBS) system for messages and a Digipeater (SBDIGI) for relaying packet messages to other systems. It runs on a Kantronics KPC3 TNC and broadcasts on 145.050 at 25w. It has incredible reach easily reaching other packet stations down the coast of California. Recent modifications were to add KA-Node capability. This allows us to connect to out KN-Node (SBNODE) and connect to other KA-Nodes. You can connect from node to node to “chain” a connection from here to almost anywhere within a reasonable distance. Similarly, others can reach us from remote locations the same way.

I also installed two of my own packet stations here locally. They are mostly for fun and have nowhere near the coverage the La Cumbre Peak station has. However, they allow me to have my own mailbox system and people can leave me a message on my own systems.

Packet radio is far from dead. In a SHTF emergency, packet capabilities will allow 100% accurate text based messages to be sent quickly and easily. In my opinion, this is an extremely valuable skill to have and even if its popularity is not what it once was, it enhances our capabilities as individual amateurs as well as a club. It isn’t as complicated as it may seem, and is actually fun and challenging.

We discuss and operate packet on the Tuesday night SBARC Digital Modes Net, so if you have an interest, be sure to check in.

– Brian K6BPM

Mesh Network Status – April 9th, 2016

Our three nodes at Gibralter Peak are working extremely well. We have members linking up from Goleta to Carpinteria and several points in-between. There are about 5 nodes online now and another 5 or so coming up soon! The node for the club station is programmed and ready to go, but installation on the mast was delayed because of rain.

We still need to raise funds to build out the La Vigia site on the Mesa. We need 2 or 3 Ubiquiti Nanostation nodes there and a ToughSwitch network switch. All the equipment will cost us about $400 and any help our members can offer will be greatly appreciated. If you can help with a donation please click here.

Our next step will be to connect over the mountain to the Santa Ynez Valley. We’re very lucky to have access to all the great repeater sites that Bill W1UUQ has spent many years cultuivating. This enables is to to some great things with emergency and general communications of all kinds and we hope to utilize these assets wisely to enhance our communications abilities.

Windows Audio Issue and *NEW* Permanent Fix

This week a bug report rocked the digital modes ham world.  Apparently the Texas Instruments audio chip used in many popular devices had a conflict with many version of Windows and was ruining receive performance on all digital modes.  This was especially troubling since it affected many popular radios and audio interfaces including:

  • All Icoms with built in USB Audio
  • All Kenwoods with built in USB Audio
  • All Yaesus with built in USB Audio, as well as the SCU-17 Interface
  • All Signalink USB’s

For a few days after the discovery, there was a known workaround that fixed the issue temporarily.  Today, a permanent fix was discovered which solves the issue even after the computer is restarted.   This YouTube video details this new permanent fix but for those who want just the facts, here’s what you have to do to optimize Windows settings to fix the bug.  These instructions are from Tigertronics, the makers of SignaLink, however the steps should work with any of the affected devices or radios:

1 – Right-click the white colored speaker icon located in the
lower-right corner of your desktop and select “Recording Devices” from
the pop-up menu.

2 – In the new window that opens, click one time on the SignaLink’s
“Microphone – USB Audio Codec” sound card to select it and then click
the “Properties” button.

3 – In the Properties window that opens, click the “Levels” tab.

4 – Right-click the percentage display to the right of the Level slider
and then select “decibels”.

5 – Lower the Level slider to “0db” or as close as you can. This is
“-0.4db” in Windows 7. It might be slightly different in Vista, Windows
8 and 10, but in any case, the closet value to 0db will work just fine.
Note that you can use the left/right arrow keys to move the slider
once you’ve clicked on it. This might be easier than using your mouse.

6 – Click OK, then click OK on the Recording Devices window.

7 – That’s all there is to it!

Digital Mode Emergency Communications

Last evening (May 5th) we were introduced to digital mode software that is used for emergency communications during the ATV Digital Modes Net . While digital emergency communications use essentially the same types of software and protocols as popular digital modes, additional software is used in emergencies when it is necessary to send specially formatted information and when accuracy is vitally important. The official name for this is NBEMS, or Narrow Band Emergency Communications Software. Many amateur radio operators involved in everyday digital HF communications are also proficient with NBEMS as well. It is a good skill to have, and it is not just limited to HF. Many times 6m, 2m and 440 FM are used for NBEMS as well.

ARRL RAdiogram

ARRL Radiogram

Last night we focused on the most familiar of these formats, the ARRL Radiogram. If you took your technician test in recent years, you were probably introduced to the radiogram and how it is used. If you don’t remember it, that’s okay, because hardly anyone actually knows how to send or receive one. You send it from one station to other stations monitoring the frequency. What they receive actually looks like a regular telegram! It can be printed and delivered, or the recipient can follow the instructions requested by the sender.

So how is a radiogram used? Let’s say there was a major earthquake and Santa Barbara was cut off from normal landline and cellular communications. How would you let friends or relatives know you were okay? Well, you could get on HF if you have that capability and try and contact another ham somewhere and ask him to relay the information to someone for you. Hopefully the other operator will get the information right the first time, because it entirely possible you won’t be able to contact that same operator again.  But what if you could send the equivalent of a telegram? Then you would be assured that phone numbers, addresses, whatever information you need to pass would be sent with 100% accuracy and the message relayed to your friends or family. This is the purpose of a radiogram.

Emergency communications are important. At least a few people in Santa Barbara should know how to send radiograms and use the other emergency message protocols. In an emergency there may be a need to send accurate data to a distant location and have confidence that it will arrive where it is intended. If this interests you, check out the ARRL website for more information, and tune in to future ATV Digital Modes Nets on Tuesday evenings at 8:00 pm and listen in on our discussion. Or better yet, check in and learn how to participate!

Digital Voice Modes Explained

Below is a link to a YouTube video from Ham Radio Now dated March 3, 2015. This video features an interview with the inventor of FreeDV, a digital voice mode we often discuss and operate on the ATV Digital Modes Net.  The video runs about 70 minutes, but if you are at all interested in digital voice, it is extremely interesting. They discuss the current “state of the art”, new hardware products, and research into new VHF/UHF modes. The last 20 minutes or so are particularly interesting as they discuss a new implementation of TDMA in ham radio VHF/UHF communications that has the potential for completely redefining how repeaters work.