Saturday, November 21, 2020

A New HF Station that's Similar, but Different

By Bennett Kobb

On October 21, 2020, DPA Mac LLC filed a FCC license application for a new, DRM-based International Broadcast Station to be located in Maple Park, IL. The principal is San Francisco entrepreneur Seth Kenvin and its technical consultant is Tamir Ostfeld of Raft Technologies, an Israeli developer of low-latency HF systems for so-called algorithmic trading.

No station devoted to algorithmic trading has ever been authorized for regular commercial operation in the U.S., as there is no formal radio service or spectrum allocation for that purpose. Several such stations have been licensed in the Experimental Radio Service (ERS), which is ostensibly for scientific studies only.

If the FCC licenses DPA Mac, it will be the first such station to make the transition from the ERS to regular, non-experimental licensing. This station would be the successor to experimental station WI2XXG. Other than the license document, the FCC has withheld most of WI2XXG's records from public disclosure since it was first licensed in 2017.

DPA Mac is similar to other DRM stations on which we previously reported: WIPE in Alpine, NJ, which is built and is waiting on its FCC license; and WPBC, proposed for Batavia, IL. With regard to their use for non-broadcast, private data transmissions, those stations made general and non-descriptive representations to the FCC. On the other hand, DPA Mac's license application is fairly transparent. The station aims to transmit "investment data from points within the United States to locations outside the United States carried over a channel immediately adjacent to the HF broadcasts...a low-power, low-latency digital data transmission service provided to private investors, including small- and medium-sized firms."

This service "will provide the necessary financial support to deploy and sustain the HF broadcasting business for the benefit of the public now and into the future." The data component, it said, will fund an "over-the-air, commercial-free audio broadcast of U.S. financial news and similar information to populations outside of the United States that have access to a standard, commercial, off-the-shelf HF receiver."

Waivers of FCC rules

DPA Mac requested waivers of certain FCC rules. Its station would run 2 kW transmitter output power, while Rule 73.751(c) requires a minimum mean power of 10 kW if digital modulation is used. "Technological advances have rendered a minimum power requirement obsolete," the company said, "and DPA Mac's technological showing demonstrates that it can successfully operate at a much lower power of 2 kW. Operating at this lower power will increase the efficiency of transmissions and reduce the likelihood of harmful interference to adjacent band operations, allowing DPA Mac to maximize use of this spectrum."

One of its proposed eight frequency bands is 7.342-7.4 MHz, which is not available to International Broadcast Stations. Footnote US136 to the Table of Allocations restricts use of 7.3-7.4 MHz to certain fixed, land mobile and maritime mobile stations. Another FCC rule, 73.702(j), concerns assignment of one frequency for use at a time, while DPA Mac said its "lower power transmissions are more susceptible to disruption from atmospheric changes and other source[s] of interference than traditional high-power transmissions are. To overcome these challenges without raising power, DPA Mac may need to use more than one frequency at any given time to maintain a continuous, uninterrupted connection to listeners."

The company also requested a limited waiver to give it more time to find a location for an auxiliary transmitter. "DPA Mac is immediately able to broadcast its programming to the foreign public using its main transmitter," it said. "Auxiliary transmitters provide a back-up means of transmission but are only necessary in rare circumstances."

Looking ahead

The FCC rules for International Broadcast stations don't accommodate non-broadcast data communications to private customers. All such transmissions, including "datacasting", are limited to broadcasts for reception by the general public - at least until the FCC changes the rules, ignores non-public communications as insignificant, or interprets or waives the rules to allow them. DPA Mac's application is the third to propose such operations, and is certainly the most explicit.

In addition, if the FCC allows a reduction in minimum power from 10 kW to 2 kW, it could improve the economics of private shortwave broadcasting considerably. Perhaps the FCC could reduce the costly 50 kW AM minimum power as well.

What is certain is that the FCC can't sit on these license applications forever. Someday these new DRM stations will go on the air, and perhaps even change the face of private U.S. shortwave broadcasting.

Monday, November 16, 2020

DRM from Komsomolsk Russia

DRM from Komsomolsk Russia is now audible most afternoons here in Oregon USA on 9540 kHz from about 2130 UTC per Brendan in Washington. He saw 18-19 dB SNR. I've had solid 15 dB SNR here.

There is an interfering signal (RHC or CRI ) on 9535 kHz but it eventually fades and decode from Russia becomes strong. They are playing a repeating music loop which gets tiresome, but at least they are getting a signal into CONUS! Tweet your decodes with #drmlog please.

Saturday, September 26, 2020

Details on Rádio Nacional da Amazônia DRM tests


With the recent excellent news coming out of Brazil, I took a few moments to contact our longtime DRM friend Rafael Diniz. He filled me in on some of the aspects of the upcoming DRM tests there:

Rafael, what is the current national status of DRM for digital broadcasting?

The digital radio discussion is stuck, mostly locked by the commercial broadcasters which publicity expressed against the digitization of the radio (citing, for example, the ongoing expenses of the broadcasters with the AM to FM migration, the crisis, and so on). Digital Radio seems a treat to the commercial broadcasting sector, but I will not elaborate more about it, as this discussion would take at least a 15 pages introduction.

 Can you tell us a little about the broadcast chain for this upcoming test? 

The broadcast chain will be a Brazilian BT Broadcast Transmitter 2.5kW HF tx, The exciter is a Digidia one, and the CS we'll experiment with different configurations, including Digidia and Fraunhofer options. The antenna is a huge HRS one beamed (with reflectors) to the north (good for US!), with between 16 and 20db of gain (Rodeador Park has many huge HRS antennas).

Will there be experiments similar to the recent work at KTWR using different parameters to see what works best? What about xHE-AAC?

We plan to use the best possible audio, which, if equipment permits, will be xHE-AAC audio and multimedia content. The idea is to also test 20kHz bandwidth, which will allow more than one audio program over the transmission, together with multimedia content.

 What will the content be?

Rádio Nacional da Amazônia content, the same of broadcast in 6,180 kHz and 11,780 kHz.

Is there any long term plan, or is this simply a feasibility test?

EBC is the process of purchase of two 100 kW DRM transmitters, to be delivered sometime in 2021 to really provide a steady digital reception even with the smallest battery powered receiver in all parts of the Amazon rainforest region. Concerning the long term - is the hope that this DRM transmission raise awareness of digital radio in the country and can change the minds of the commercial broadcasters about digital radio... and also save the MW band, which is getting empty - which is good and bad at the same time... with clear channels DRM nighttime reception can be fun again.

Thank you Rafael for your time and such great news. We look forward to more details and even more to signals making it to North America! Rádio Nacional da Amazônia is often heard here with great signal level and quality.


Wednesday, September 16, 2020

Hope springs eternal with DRM receivers

Please take a look at this slideshow showcasing the progress being made on the DRM standalone receiver front. A few new ones here that look interesting. Particularly interesting to see Korean manufactures back in the game. I think that marks a first since the demise of MSWay 9 years ago.





Sunday, September 6, 2020

Radio Engineer Files Objection to WIPE

Story by Bennett Kobb:

On September 3, radio engineer Alex Pilosov of Shortwave Solutions filed with the FCC an objection to WIPE, the DRM-based HF station of Turms Tech of New York, presumed to be ready to broadcast from the Armstrong Tower in Alpine, NJ.

WIPE is suspected to be intended mainly for secret, non-broadcast message transmission for private trading clients while broadcasting financial and economic news for the public.

WIPE is not yet operational. The station is waiting on its FCC license, but Pilosov took aim at possible glitches in its license application. He also raises the issue of whether U.S. shortwave stations can legally conduct non-public telecommunications in the broadcast bands in a service limited to broadcasting.

Pilosov is a consultant to HF stations in the Experimental Radio Service, which are not constrained by the broadcast rules; thus he or his clients are prospective competitors to WIPE. This is Pilosov's second FCC objection. He also filed against the application of Parable Broadcasting for WPBC, a DRM HF station proposed for Batavia, IL.

As mentioned in our previous story on WIPE, Turms Tech submitted to the FCC two different locations for its transmitter site, one in New Jersey and one in New York City. The company apparently did not supply an antenna registration for this site, which would have helped resolve the inconsistency.

He identified further possible problems with the station's technical parameters. "Every component of transmission system proposed by Turms (coaxial line, amplifier and antenna) is under-rated and inadequate to meet the minimum power requirements," he found, leading to possible violations of safety codes and hazards from overheating and arcing.

Where Turms specified a six-element antenna, the manufacturer described a four-element antenna; where the company depicted two antennas, its other exhibits apparently show a single antenna. Pilosov added that the company's claimed antenna gain is less than indicated by the antenna manufacturer, and the antenna is rated for less power than the minimum power the FCC requires of these stations.

"Due to location and orientation of antenna, it appears that Turms is planning to transmit financial data using 'datacasting' feature of DRM, like recent application by Parable Broadcasting in Illinois," Pilosov wrote. "Turms does not explicitly describe whether such programming is 'broadcast to general public' or effectively a point-to-point service as a 'multiplex' carrier of other programming. It is well-established that 'broadcasting' only includes transmissions intended to, and received by, the general public."

He cited the FCC's description of DRM datacasting as a "wide-area" service, which would not describe point-to-point communication to specific receivers at fixed locations. In a TV-related proceeding, the FCC defined non-broadcast services as requiring special equipment to receive and decode, and  including a contractual relationship between provider and receiver.

The three filings against Turms/WIPE and Parable/WPBC -- two from Pilosov, and one, submitted by the High-Frequency Parties (Christopher Rumbaugh, Kim Elliot and Bennett Kobb) against Parable -- raise substantive issues. We have no indication yet, however, that the FCC will address them, or do anything but routinely grant the licenses and carry on with the U.S. HF broadcasting service as it has for the more than half-century it has existed.