Survey Results: U.S. 2018 70cm Band Spectrum

A poll concerning the use of 420 to 450 MHz spectrum in the United States was posted on the popular QRZ.com website on August 29th 2018.  Participation was open through end of 2018.

There were actually a total of 83 votes, but 6 respondents indicated they do not use 70cm or only listen from time to time. This would have represented 7.22% of the total results. All details below do not include those 6 responses since they do not actively use 70cm spectrum in the United States.

Maybe 2019 will be different for those and others not currently using 70cm for many different activities.  Here are the results of the 2018 survey.

Methodology & Goals

The reason to run a survey was to quantify the current and major use cases of the 420-450 MHz amateur spectrum in the United States. There is currently a huge disruption taking place thanks to digital voice communications through modes such as DMR, Fusion, D-Star and others and a survey helps to add fact to this statement.

The survey included 10 questions focused on use cases or common applications of the spectrum in question. These questions were than able to be aggregated into 5 general categories of:

• Analog FM Voice - Repeater based communication, Point to Point Simplex and short range hot spot use for things like Echolink were the three questions asked. The survey indicated 44.17% of active 70cm users use analog FM communication methods.

• Wide Band Modes - There was only one question asked in the 2018 survey about wide band modes and focused on amateur television or ATV. This type of activity requires channels four or more times wider than the widest audio only modes.  Only 2.41% of the survey respondents use wide band modes in 70cm spectrum based on the 2018 survey.

• Digital Voice Modes - Repeater, simplex and hot spot use cases were the three digital voice mode use questions within 70cm spectrum. For relatively new technology, an impressive 23.38% of survey takers reported to use digital voice as a primary activity on 70cm in the United States.

• Weak Signal Modes - Two weak signal questions were asked that covered single side band voice (SSB) and all other terrestrial or natural objects often associated with weak signal work such as beacons, EME bounce, Morse code and other things such as FT8, PSK31 and WSPR.  11.69% or survey takers enjoy the challenges of weak signal mode operation on 70cm with 7 of 9 category votes captured by SSB, likely during UHF contest periods.

• Satellite Modes - Only one question was asked since most all satellite operation takes place in a protected portion of the 70cm spectrum from 435 to 438 MHz. Uplink and downlink use of any mode used to make contact through man made objects like a space station or satellite were easy to ask in one question in the 2018 survey. With 18.18% of the survey results coming from satellite based use cases, it is clear that amateurs who use 70cm for this reason are active and create a strong reason to have dedicated spectrum for this sort of application. Most any mode is permitted and 2019 will start to see a rise in digital voice satellite use thanks to the recently launched and operational D-Star ONE.

Additional Survey Insights

The below table lists out all questions 9 of 10 questions and the category they contributed towards.

Some Additional Thoughts

Considering at of the end of 2018 there are 755,416 licensed radio amateurs in the US according to official FCC records, this survey sample size is microscopic. However, the total number of active annual radio operators is probably closer to 20% (1 in 5) This would equal 151,083 of  active amateurs in the last year somewhere across all amateur spectrum and not just on 70cm.

The QRZ.com website is pretty popular and seemed to be the best place to field a survey since its fairly agnostic and does not favor those for or against the direction of the ARRL which may have clouded the survey results, but likely would have increased the total number of respondents.

QRZ.com may attract more forward thinking amateur radio operators who are open to learning about new and advanced things to do within this hobby where they can be openly discussed. Many members of the ARRL are on QRZ.com, but only the ARRL can report on things from its membership which is only 170,000 as of 2016 or 22.5% of all amateurs in the US.

While ARRL membership totals are pretty close to the number of estimated active amateur radio operators, the ARRL also includes some non-US members, clubs and supporters so may not accurately represent those most active in the amateur community.  Its total membership may only represent a smaller number of active amateur radio operators than it may care to admit but may be changing due to new leadership in 2019.

If we were to consider that possibly 3 of every 10 active licensed hams (151,083) also frequent QRZ.com, the total pool of likely respondents would have been about 45,325 and potentially 1 of every 7 QRZ.com visitors who may have even found the survey area and logged in to take it would mean roughly a total pool of 6,346.

Ergo, 83 responses from a pool of 6,346 is 1.3% which is right on the border for statistically significant survey results considering that a professional firm touts results over 2% as very successful.  A 2019 survey hopefully will do much better.

If a 2019 survey for 70cm use cases can be organized by the ARRL and other organizations on neutral grounds, it would likely be more accurate based on total responses and prove beneficial towards leadership in emerging aspects of the hobby to create better experiences for all amateur radio operators in the United States looking at digital voice operation, best practices and equipment purchasing decisions.

Questions?  Comments?

If you wish to contact the team responsible for this article, please send a detailed email to 4info@hvdn.org  but remove the "4" or your message will not go through.

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HVDN [reset] = Is the "Feather" better?

Embedded computing and open hardware in the form of Raspberry Pi, Arduino and a few others have propelled creativity in the maker, electronics hobbyist, STEM education and amateur radio communities in recent years.

A new format standard called Feather has recently come to market and is very exciting, so lets find out why.

Embedded computing you say?

Since 2012, there have been over 19 million Raspberry Pi sold when combining all the different (and improved) versions sold over the years.

Perhaps the biggest competitor to the Raspberry Pi has been the genuine Arduino family of micro-controller boards with an estimated few million shipped.

Both "embedded computing" ecosystems have spawned various forked versions that illustrate the success these two standards have demonstrated both for hardware and software compatibility.

HVDN [reset] is a sub-series of content that compares
different enabling or disruptive innovations relevant to the
maker, electronics hobbyist and amateur radio community.

One reason that has made both devices popular for add-on device or "hat" accessory development has been standard sizes and pin or GPIO configurations.

This has helped developers create exciting applications quickly & reliably

A new standard called "Feather" has arrived recently and promoted by Adafruit and Sparkfun, both known for providing a range of original add-on products to build even better Raspberry Pi and Arduino based projects.

18 different Feather based products using standard sizing and connections

The [reset] moment

Thanks to Limor Fried and her team at Adafruit along with a number of different vendors like Particle, the new Feather and related terms such as "Feather Board" and "Feather Wing" are poised for a lot of success.

This HVDN [reset] article will explore the "Feather" open hardware ecosystem in  comparison to Raspberry Pi and how it simplified development of our latest project by standardizing on this new small form factor wireless enabled embedded computing standard.

Different sizes of Pi for all appetites

Let's look at how the size of the most well known and current Raspberry Pi offerings look next to each other.

• Raspberry Pi 3B  = 85mm X 56mm
• Raspberry Pi Zero = 65mm X 30mm
• Raspberry Pi Compute  =  67mm X 31mm
• Feather Classic = 51mm X 23mm

Pictured from top left clockwise are the Pi Compute 3 Module,
Raspberry Pi 3 and Raspberry Pi W Zero

Raspberry Pi has been chosen by HVDN to compare against the Feather format because they all offer wireless connectivity.

Arduino has too many variants to compare that have a similar size to Feather but do not offer wireless connectivity. ESP32 and ESP8266 boards have too many versions.

A major benefit with many of the smaller Feather based products
compared to the slightly larger Raspberry Pi Zero is built
in battery charging, power options and connectivity options.

Arduino versions such as the Nano, Micro, and Lilypad along with the Adafruit Trinket are left out of this review since they lack wireless connectivity.

Plucking Feathers

Specifications help drive standards and adoption, so Adafruit has everything documented on its website to make development easy for most everyone.

Standard dimensions of the Feather help
create easy product development and compatibility

Key Feather Physical Dimensions:

• The 'classic' Feather and Wing size is 0.9" x 2.0" with 0.1" holes at each corner.   

• There is one 16-pin breakout strip on the bottom side, centered 1.0" from the left edge.  

• There is one 12-pin breakout strip on the top side, 1.2" from the left side.  

• The spacing between the two strips is 0.8"  

• Don't change the GPIO spacing or location, or you will not maintain compatibility with Wings! 

Key Feather "In/Out" Specifications

Using the Particle.IO "Argon" product as the example, here are the connection details copied from the super helpful datasheet.  Many of the elements found in certain Particle products were even part of the attendee badge at this years Open Hardware Summit to show example of an embedded application in the real world.

So, what is the project?

In 2017  HVDN started to develop a modern field strength meter that has remote sense and analytic capability as featured in the Field Strength Meter Monday series.

After working out the actual sensor part of the project and offering for sale a limited run of stand-alone sensors, we then set to work to redesign the RF signal strength sensor unit to fit as a "hat" onto a popular embedded computing board.

The initial plan was to use the Arduino Nano because it was low cost and easy to program but was soon abandoned because certain versions of it used non-standard USB drivers to update or interface to the device.

A later version looked at standardizing around the STM32 based ESP32 and ESP8266 based embedded computing devices because they both offered integrated battery charging and wireless functionality. They also used the very flexible microPython programming language.

WEMOS ESP32 based Wi-Fi/BLE
4MB microPython IoT device

Quality and version control of these different ESP32 or ESP8266 based boards proved hard to develop easily replicated results around, but working prototypes showed the proof of concept was sound and could be improved upon.

Looking at Feather based options again seemed ideal due to a price drop and additional features. 

It was decided to build this project around the Particle Argon (Wi-Fi + Mesh)  and Xenon boards (BLE + Mesh), with potential support for the Boron (LTE + BLE + Mesh) board at a much later date.

Making projects simple with Feather

The Adafruit Feather based options helped simplify our project design and also allowed even more features to be added!

Future articles will cover microPython coding basics, computer-aided circuit design and fun applications for this exciting project.

Here is the HVDN-FS1....