Spectrum Protection & Utilization

Jeff, W4DD, has created a Windows-based app that maps RFI from power lines as you drive along side them.  I’ve been experimenting with the software to develop some guidelines for its use by the RFI teams.  I know several others on the teams are doing the same thing.  The Icom 705 in each team has both the GPS and CI-V capability to support gathering the required data.  The process begins by installing the app, available on request, and creating a directory or folder to receive the data.  The vehicle is then equipped with a Hamstick for 10 meters https://nediv.arrl.org/wp-content/uploads/2023/12/rfi-10m-antenna.jpg (I haven’t tried other bands but this is the one Jeff recommends) and a team Icom 705 is connected via a micro-usb port on the 705 and a usb port on a laptop that has the Icom drivers installed on it (available on the Icom America website.) https://nediv.arrl.org/wp-content/uploads/2023/12/rfi-test-setup.jpg I’ve installed several ferrites (available on Amazon) on the usb cable to suppress the usb port noise when in operation.  If all is connected properly, starting the RFID software displays that the GPS and the CI-V S-meter reading from the Icom 705 are recognized.

I tune the Icom 705 to 28.5 MHz in the AM mode.  Start the data gathering process by providing a name for the file when requested.  Start driving the test route at about 30 MPH paying attention to traffic so you don’t become the lead car in a caravan.  At this point I strongly recommend that you work with a partner so you can drive and not need to pay attention to the data being recorded.  The faster you drive, the further apart the data points become so you can cover more territory but you may miss the detailed location of an RFI source.  You can zoom in on a particular area of the map and examine it in Google Earth to gather more detail.  If you are hunting a real source, you may want to repeat a run.  It is helpful to have a spare laptop battery.

When you complete a run, connect to the internet and go to the GoogleMyMaps site.  Upload the data file you created into a new map.  Look at the data and use color (select style by s-meter) to single out the high noise data points, i.e. s1-s5 colored green, s5 – s7 colored yellow, s8 and higher colored red.  I used a slightly different set since I wanted a bit finer scale. https://nediv.arrl.org/wp-content/uploads/2023/12/rfi-software-test-run.jpeg

Once you’ve identified a problem location, the use of the team VHF/UHF log-periodic to find the specific pole and an acoustic dish (I use an MFJ dish) to find the particular faulty component are the last steps.

I’ll refine this process with the teams’ inputs as we go forward but my testing so far is very positive and I believe that Jeff, W4DD, has provided us with a valuable tool for finding powerline RFI.

Jay Taft is leading an effort to expand mesh networking in New Hampshire in support of the NEDECN digital network.  The goal of network expansion is to provide a robust, commercially independent, emergency communications backbone as well as a commercially-independent general purpose amateur radio communications facility.  This effort is in parallel with similar efforts in RI and ME that are in progress.

The overall objective of the NH effort is establishing 5 GHz RF links among DMR and other sites in southern NH. During September the NH team established a 33-mile link from Crotched Mt to Walnut Hill which set up the potential to extend the mesh network to the east, north and south.

Participants in the September project were Bill Barber NE1B, Paul Blais KC1KMM, Bill Fortin KB1SGK, Ted Gamlin K1OX, Jen Herting KD2BEC, Bryan King KX1B, Wally O’Donnell N1GLT, and Jay Taft K1EHZ.

On September 9th, a joint team from New England Digital Emergency Communication Network and the Merrimack Valley Amateur Radio Association installed a 5 GHz mesh router on the K1OX tower on Walnut Hill in Chester, NH. (Photo of Wally N1GLT on the tower.) On September 21st the NEDECN and MVARA team updated the 5 GHz router configuration on South Uncanoonuc Mountain in Goffstown, NH. (Photo of Bill KB1SGK on the lift.)

The link from Uncanoonuc to the NEDECN site on Walnut Hill in Chester, NH (19 miles east of Uncanoonuc) turned out to be marginal due to obstruction by rock and foliage, and subject to RFI from other radios on the summit, however, the 5 GHz signal from the router previously installed on Crotched Mountain in Francestown, NH (14miles west of Uncanoonuc) is received at Walnut Hill (19 miles east of Uncanoonuc) with an excellent signal to noise ratio across the 33-mile path. The team is evaluating this path to see how it holds up over time.

These mesh expansion projects, eventually linking them in a New England – wide network, as well as others like them nationally are key to staking amateur radio’s claim to these frequencies and preventing encroachment by commercial interests.

The teams active in this effort meet semi-monthly on Zoom and communicate using nemesh@groups.io.  If you are interested in becoming involved, please consider joining the iogroup to get started.

The national news has recently covered the decision by Ford Motor Company to continue to provide AM radios in their EV’s, after first announcing AM radios would be discontinued.  The noise from battery systems interfering with reception was the reason cited in the news. 

We hope that this means that the RFI shielding in these EV’s will be upgraded to suppress the RFI generated from these EV systems and that other auto manufacturers will follow suit.

Hams suffer from the RFI generated by the internet of things, solar energy systems, LED lighting, faulty power line components, motor controllers, electric fences and many other sources with more emerging all the time as technology delivers more and more devices that generate RF energy as a by-product.  EV’s are yet another example but the national commitment to replace the fleet of gas and diesel driven vehicles with EV’s in the next decade is an order of magnitude more of concern.

It is reasonable to question whether the FCC’s self-certification approach is sufficient for EV’s given the potential impact to the RF spectrum, not just to amateur radio but to public service frequencies as well.  The 60 meter band, for example, is used by government services with amateur radio secondary.  If EV’s are too noisy in the AM broadcast band for them to receive many AM stations, is it likely that strong harmonics will impact signals at 5 MHz?

Congressional hearings are underway to consider the impact of removing AM radios in vehicles.  The issue appears to be uniting both progressive and conservative senators for commercial reasons.  It seems to me that this is an opportunity to surface the issue of RF pollution of the spectrum to our lawmakers, not just for the sake of amateur radio but in the broader public interest as well.

The CT RFI team met at ARRL HQ in Newington, CT on Saturday, February 25.  Training was performed by Rob Leiden, K1UI, New England Division Assistant Director, with the help of Ed Hare, W1RFI and Steve Anderson, W1EMI of the ARRL Lab.  A reference handout, developed with the assistance of EMA Team Lead Dan Brown, W1DAN, provided information about the use of the RFI team equipment.  Four of the seven sections have now been trained and received their equipment, funded by a grant from ARDC.  Another session is scheduled for Nearfest in Deerfield, NH on Saturday, April 29. RFI casework is already in progress with several cases already resolved. Interest in this effort continues to grow as the teams become better equipped and the success of their work becomes known.  If you are interested in helping out and have some experience finding and correcting RFI, contact the team lead for your section for more information.

Jay Taft, K1EHZ, and Ken, N1KWG, announce there will be a mesh network training session on Thursday, Feb. 2 at 7:00 pm.

All those who are interested are welcome to join the meeting. 

The slides to be used for the training can be found on the MVARA website:

http://merrimackvalleyara.org/wp-content/uploads/2023/01/Merrimack-Valley-Digital-Network-Training-Presentation.pdf

If you are interested in participating in the upcoming session, please contact Jay or Ken at their qrz.com addresses.

On January 21, the RFI teams from EMA, WMA and RI attended the 1st New England Division RFI training session, held at New England Sci Tech.  The teams received information about some general team-related matters as well as information about the equipment features and techniques for its use.  Nancy, KC1NEK, from the RI team has posted some photos at: https://photos.app.goo.gl/Cy3nTJsdvka7YEwM7.  These three teams now have the equipment funded by the ARDC grant in their possession to use for helping hams with their RFI problems.  Hams needing that assistance should start with the rfi troubleshooting guide.

The guide and decision tree will direct you to the RFI team page when you use the tree to guide your investigation and find you need further help.  You then will see who your team members are and have the opportunity to answer a few questions so they can help you.

Your information will become part of a record that will be used to identify likely RFI sources for future cases.  Even if you find the RFI source yourself, let the team know what you found so that your information can be added to the record keeping.

Even before they received the new equipment, the teams have already been helping hams in the Division find and eliminate RFI and this new equipment will greatly enhance the teams’ capabilities.

The next training session is scheduled for Saturday, February 25, at ARRL Headquarters in Newington, CT.  This session is open to the CT team members and members of the ME, VT, NH teams on request and by invitation.

The last session currently scheduled is Saturday, April 29, at Nearfest in Deerfield, NH.

WZ0Z in MA and N2MH’s “Supernode” in NJ have added tunnels into the New England mesh system, bringing the number of states linked to 5; these include nodes in ME, NH, CT, MA and now NJ.  Recent ARDC and ARRL grants in ME and RI offer the potential for further expansion and the recent partnerships between the NH mesh and NEDECN nodes raises the possibility of seeing more such partnerships throughout New England.  These connections represent a first step towards linking New England with a system that can survive a commercial internet outage, whether due to natural disaster or cyber-attack.  The nodes, mostly on the 2.4 and 5.8 GHz bands, utilize frequencies under threat from commercial interests and represent an enhanced facility for emergency communications including email, chat, iphone, mapping, remote camera operation and monitoring and many other apps found on the internet and familiar to ARES served agencies.  

If you operate a mesh network in New England and would like to tunnel into the existing mesh system, please contact Rob Leiden, k1ui, Assistant NE Division ARRL Director, Spectrum Protection and Use at k1ui@nediv.arrl.org.

From ARRL News:

12/22/2022 – Congresswoman Debbie Lesko (AZ-08) introduced a bill in the U.S. House of Representatives (H.R. 9664) on December 21, 2022, to require that the Federal Communications Commission (FCC) replace the current HF digital symbol rate limit with a 2.8 kHz bandwidth limit.

After being petitioned by ARRL  The National Association for Amateur Radio® in 2013 (RM-11708) for the same relief, in 2016 the Commission issued a Notice of Proposed Rulemaking (WT Docket No. 16-239) in which it agreed that the HF symbol rate limit was outmoded, served no purpose, and hampered experimentation. But the Commission questioned whether any bandwidth limit was needed in its place. Most amateurs, including the ARRL, objected to there being no signal bandwidth limit in the crowded HF bands given the possibility that unreasonably wide bandwidth digital protocols could be developed, and since 2016 there has been no further FCC action.

In conjunction with introducing the legislation, Congresswoman Lesko stated that “With advances in our modern technology, increased amounts of data can be put on the spectrum, so there is less of a need for a regulatory limit on symbol rates. I am pleased to introduce this important piece of legislation to update the FCC’s rules to support the critical role amateur radio operators play and better reflect the capabilities of our modern radio technology.”

ARRL President Rick Roderick, K5UR, hailed introduction of the bill. Roderick stated that “the FCC’s delay in removing this outdated restriction has been incomprehensible, given that the biggest effect of the delay is to require totally inefficient spectrum use on the already-crowded amateur HF bands. I hope that the Commission will act to remove this harmful limitation without waiting for the bill to be passed.”

ARRL Legislative Committee Chairman John Robert Stratton, N5AUS, added that “the symbol rate limit hampers experimentation and development of more efficient HF data protocols by U.S. amateurs. For all practical purposes the field has been ceded to amateurs outside the U.S., where there is no comparable limit. Removing the restriction not only will allow U.S. amateurs to use the most efficient data protocol suitable for their purpose, but it also will promote and incentivize U.S. amateurs to experiment with and develop even more efficient protocols.”

As the RFI Teams prepare to be trained and receive the equipment purchased with the $23.6K ARDC grant, additional team members are sought in ME, VT and RI.  Training and distribution of equipment will occur in early 2023.  This is an opportunity to help your friends and your club and learn something new with some very sophisticated equipment.  You can see who has already volunteered on the New England RFI Team page.  If you’d like to see your name and callsign on the team page, please contact your section team lead listed on the page.  RFI is a major concern for all hams and the knowledge you receive will help you and help others.  For more information, please email me at k1ui@nediv.arrl.org.