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

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.

Digital Mode and ATV Net Time Change?

Tonight on the Digital Mode and ATV Net we are going to request input from participants about the idea of changing the net times from 8:30 pm – 10 pm, to 8:00 pm to 9:30 pm. The original time was chosen back when there was another ATV net running in another county that ended at 8:30. After that net was over, some on those participants moved over to the SBARC ATV net. These days there is very little discussion (if any) about ATV, and much more about digital voice and special modes and the participants are mostly local club members. So there is no particular reason why we cannot start the net a little earlier and end a little earlier. It is the opinion of the net control that  we may be able to attract more participants, and more participants can stay longer, if we start and end at a more convenient times.

So what do you think? If you have any opinion on this please weigh in by leaving a comment below.

ATV Special Modes Net – February10, 2015

We had a great turnout this week with 9 check-ins to the net. Several Club members have recently purchased new Yaesu digital VHF/UHF radios, so this net is becoming the place to come to learn about this exciting new twist on day to day FM voice communications. Everyone that has experienced using this special digital mode cannot stop raving about the clarity and total lack of noise. Often, when two or more members go off to another frequency to experiment with digital, it is difficult to get them to come back! As we continue to experiment and test we’ll devote a portion of this net to talking about digital FM each week.

During the past couple of nets we have also been talking about operating with JT65. To many, this low power, weak signal mode seems somewhat boring, so we talked about some of the finer points this week. Low power, weak signal operating can really become an art form if one takes the time to explore it deeper than face value. Once you learn basic operation, it is not unusual to hear about operators using incredibly small output wattages in the sub-1W range and making thousand mile contacts.

We also talked about using JTAlert, an add-in product for JT65 that adds a lot of additional functionality and convenience to the two major JT65 applications. JTAlert can be freely downloaded at If you are a JT65 user, this is a useful addition to your setup. It offers a full macro system, callsign lookups, log book interface, and even allows user to user real time chat.

ATV Special Modes Net – February 3, 2015

Last nights net was very well attended with 8 checkins and at least half of us operating JT65 at the same time. KI6HGH Steve, also joined in on both Allstar and 40m JT65 from Yucca Valley. HGH and K6FLD Frank also carried on QSO’s with other hams on the band and we were all able to watch the action. Even the Shackmaster was able to find a little time in his busy Tuesday night schedule to follow along from the Club Station. This was a really great demonstration of how JT65 works and why it is becoming so popular.

We also took some time to discuss Yaesu’s new digital voice HT radios. In a week or two, we should have 5 members who have these powerful little radios and we’ll be able to add a new digital activity to our nets. These radios have a lot of interesting capabilities we’ll be exploring and learning about.

So tune in to the ATV Special Modes Net next Tuesday at 8:30pm and keep up with the latest and greatest in digital ham radio.

Digital Voice 2m Communications – First Impressions

If you get QST Magazine, it is hard to miss Yaesu’s push for their 2m/440 digital/analog radio offerings. They have been taking out 2 page ads right after the cover for some several months now. Yaesu  digital radios use the C4FM modulation method. It is currently only compatible with other Yaesu radios.

FT1DRYaesu’s base HT radio, the FT1DR, has become very reasonably priced, with most outlets selling them for less than $300. First, they are full featured dual band analog HT radios with all the features you would expect from Yaesu. But there’s more. A lot more. This radio also has digital capabilities, GPS, and APRS.

Levi K6LCM and I decided to take the plunge and order a pair of these powerful little radios. They operate just like any other quality HT on VHF and UHF analog so they are great for every day communications. Levi and I tried our first experiment with digital using simplex between his home QTH on the far western end of the ocean side of the Mesa, and my QTH on the far eastern end of the Riviera. Between us there are two hills to overcome, so we hooked our radios to our rooftop antennas and used 5 watts of power.

Wow! The first thing I saw was Levi’s callsign come up on my radio. His voice was completely natural and absolutely clear. No static, no background noise, just an absolutely clear voice as if he was next door.

There are all kinds of other cool features we have yet to experiment with, like seeing the other person’s location and relative distance. For now the bottom line here is that digital communications is not a gimmick. It really works. We’ll continue to explore the capabilities of these little radios and post more in the future.

If you want to learn more about digital voice radio, tune into the ATV Special Modes Net on Tuesday at 8:30pm. We will be discussing this more there this week.

ATV Special Modes Net – January 27, 2015

Even though the net was lightly attended, we nonetheless had another good discussion on antennas and using JT65. We operated locally on 6m for awhile, then moved to 40m and carried on a couple of QSO’s so that we could compare our long range signal propagation on PSKReporter.


Map of stations that heard K6BPM using JT65 on 15m at 35 watts is a web site that aggregates signal reports from hundreds of digital mode operators all over the world. Almost all digital mode software applications automatically report this information to PSKReporter whenever the application “hears” a callsign. So whenever you transmit in a digital mode, and another station hears your signal, your callsign and signal report are reported in real time. This is called “spotting”. It enables you to immediately see where your signal is being heard, and how strong your signal is. Data is displayed on a world map and you can easily see where and when your signal is being received. The PSKReporter site is also great for finding out where all the current activity is, and what modes are being used.

Our Shackmaster Dave is usually very busy on Tuesday nights while the station is open. Nevertheless, he tries to tune into the net and follow along with whatever mode we are working. He will have all the activity displayed on one of the shack computers. So, if you get the chance and want to see what this is all about, drop by the shack during the ATV Special Modes Net, and follow along or participate in the action!

ATV Special Modes Net – January 20, 2015

Last nights net was very active with a lot of good discussion about antennas and lead lines. Two of the participants have recently installed new end fed antennas that have impressive all band, 6m to 160m coverage. The particular models we discussed are the DXtreme from UTILMAX Antennas.

We also operated JT65 with several of the checkins participating. Jt65 is a fun mode that works especially well with very weak signals. There are several JT65 programs available for Windows and Mac. The image below was captured last month using a JT65 variant called JT65-HF-HB9HQX Edition. Click on the image below to view it full size.

JT65 operating on 10m

JT65 operating on 10m

We will be going on the air next week and learn more about this mode, so try to check in!