This transcript covers several key topics related to amateur radio activities and projects. It begins with a discussion of regulatory filings concerning the 219 MHz band, countering arguments from the Association of American Railroads (AAR) regarding interference potential. The group also reviews and confirms their opposition to NextNav's proposal to repurpose the 900 MHz band. A significant portion is dedicated to analyzing comments submitted by the ARRL (American Radio Relay League) on proposed FCC rule changes, including modernizing baud rate limits, expanding Technician class privileges, removing obsolete digital code restrictions, and notably, enhancing privacy by removing home addresses from the ULS database β a move strongly supported by the group. Project updates include Mike's work on utilizing LTE Band 40 hardware and software (VoLTE, potentially MCPTT) within amateur 2.3 GHz allocations, leveraging existing standards for ham radio use. The team discusses the recent retrieval of equipment from a failed "Remote Lab South" initiative, debating future options: enhancing the existing "Remote Lab West," establishing a new lab, conducting university outreach (specifically mentioning UCSD, SDSU, San Marcus), or liquidating the surplus gear. Paul provides insights into the actual usage patterns of different test equipment. Updates are shared on the Earth-Venus-Earth (EVE) project, focusing on analyzing Doppler spread and developing delay-Doppler communication protocols. Finally, a user interface improvement for the Ribbit digital messaging web app is noted.
Amateur Radio Regulatory Discussions, Project Updates, and Lab Logistics
0:00:17 AAR Comments on 219 MHz: Discussion of comments by the Association of American Railroads (AAR) regarding Positive Train Control (PTC) deployments. AAR argues low interference risk as PTC is mainly on railroad rights-of-way. This is countered by noting amateur use is proposed as fixed, not mobile, further limiting interference potential.
0:01:01 Justification for 219 MHz Amateur Use: Reinforces arguments for retaining amateur access, citing secondary status, reduced power, fixed locations, and digital emission restrictions as sufficient interference mitigation.
0:02:12 NextNav 900 MHz Proposal Opposition: The group plans to reiterate their opposition to NextNav's proposal to take over the 900 MHz band, citing NextNav's lack of an existing product or market and reliance on cellular companies adopting their unproven technology. A past interaction with an FCC TAC presenter highlighted misunderstandings about the proposal's viability.
0:04:35 ARRL Comments Review Introduction: The group begins reviewing ARRL's comments on recent FCC proceedings regarding rule updates.
0:05:02 ARRL Proposal: Baud Rate/Bandwidth Limits: ARRL proposes deleting obsolete LF, VHF, and UHF baud rate and bandwidth limitations.
0:05:19 ARRL Proposal: Technician Privileges: ARRL suggests updating Technician class license privileges to include some HF data and phone communication access to incentivize upgrades.
0:05:50 ARRL Proposal: Digital Codes: ARRL wants to delete and replace obsolete digital code limitations.
0:06:18 ARRL Proposal: ULS Privacy: ARRL proposes removing non-current personal information, specifically home addresses, from the amateur Universal Licensing System (ULS) records. This is strongly supported, citing personal safety concerns and overcoming past resistance within ARRL itself. The argument that addresses are needed for self-policing is dismissed.
0:09:12 ARRL Proposal: Special Event Call Signs: ARRL wants to delete the requirement for special event stations to identify with their responsible licensee's call sign hourly, relying instead on the database lookup.
0:09:33 ARRL Proposal: Paper Licenses: ARRL proposes deleting obsolete rules regarding paper license replacements, as the FCC no longer issues them routinely.
0:10:37 FCC Direction & Rule Modernization: Discussion on the FCC's preference for dynamic spectrum management and avoiding embedding specific technologies in rules, which makes cleaning up old, technology-specific amateur radio rules a lower priority but still important.
0:12:08 Action: Support ARRL Comments: The group agrees to file reply comments supporting the ARRL's proposals, aiming to add momentum even if changes aren't immediate.
0:13:51 Mike's LTE Project (Band 40): Mike introduces his project using commercial LTE technology (specifically Band 40, which overlaps with 2.3 GHz amateur bands) for ham radio.
Leverages existing standards, phones, modems.
Uses hardware femtocells (e.g., from band40.com) and open-source core network software (EPC like Open5GS).
Successfully implemented basic functions (SIM cards, calls, texts via VoLTE).
Current focus: Investigating Mission Critical Push-to-Talk (MCPTT) and Multicast (MBMS).
Challenges: Band 40 is TDD (Time Division Duplex), making SDR software implementations difficult due to timing sensitivity.
Community Resource: Project details and discussion at xcl.is and associated Discord.
0:20:00 Matthew's Update: Matthew plans to catch up on MSK modem tasks and has ideas related to the 220 MHz band to discuss later.
0:21:13 Remote Lab Equipment Retrieval: The team successfully retrieved lab equipment from Little Rock, originally intended for "Remote Lab East" and then "Remote Lab South," which failed to launch. The gear is now consolidated at "Remote Lab West."
0:22:45 Future Plans for Retrieved Equipment: Discussion on how to best leverage the duplicate set of lab equipment:
Option 1: Upgrade performance of the existing Remote Lab West computer.
Option 2: Build out a third powerful computer using a spare case.
Option 3: Use the equipment for outreach to local universities (UCSD, SDSU, San Marcus), potentially setting up a second lab site or providing gear and curriculum based on current projects (e.g., satellite uplink/downlink).
Benefit: The outreach effort forces an update to their project documentation and Statement of Work (SOW).
Option 4: If other options fail, liquidate the surplus equipment and return funds to operations.
0:28:22 Paul's Equipment Usage Assessment: Paul reflects on the actual usage of test equipment in Remote Lab West. The spectrum analyzer sees heavy use, while the oscilloscope, power supply, and signal generator are used much less frequently or for very specific tasks. He questions the value of duplicate gear without dedicated hands-on users/projects.
0:31:47 Call for Collaboration: An open invitation for suggestions or partnerships if anyone knows of a good opportunity to establish another productive remote lab.
0:32:29 Value of Remote Lab Infrastructure: Emphasis on the importance of the remote lab's powerful computers, virtual machines, and access to licensed software (Vato, Matlab) for enabling open-source development and providing valuable tools/experience to the community.
0:34:43 EVE Project Update: Updates on the Earth-Venus-Earth communication attempts:
An article based on the newsletter's link budget analysis is being prepared for a Deep Space Exploration Society (DSES) report.
Future newsletter articles will cover lessons learned, particularly regarding Doppler spread caused by Venus' rotation, and the development of a specific delay-Doppler communication protocol.
Goal: Move beyond simple carrier detection to transmitting actual information over the EVE path.
Commitment to explaining complex DSP/math concepts accessibly.
0:39:48 Ribbit Project Update: The user interface of the Ribbit web app (which generates audio tones for digital messaging over any radio) has been improved based on user feedback, changing a potentially confusing "Save and Exit" button to "Save and Continue." Plans to publicize the updated app.