Q: What kind of antenna(s) are you using?

A: There are currently three antennas in use:

  • A ChannelMaster CM4228HD receives emissions from Sutro Tower and Mount San Bruno.
  • A ChannelMaster CM4221HD receives emissions from the hills above Fremont. For reasons we have yet to determine this antenna performs best attic-mounted rather than roof/pole-mounted.
  • A Winegard HD7000R (with low-vhf extensions installed) receives RF 6 from Mt. Loma Prieta.
Q: What tuner/demodulator are you using?
A: For ATSC 1.0 we use the fourth-generation HDHomeruns (“HDHR4”), also known as the HDHomerun Connect. In our experience these are the most resilient of the HDHomeruns and actually perform better than the 5th-generation HDHomeruns (the ones with the black square enclosure). We haven’t looked at ATSC 1.0 performance with the latest generation HDFX series.
For ATSC 3.0 we use a combination of HDHomerun Connect 4Ks (Development Edition), Airwavz RedZone Receiver RZR-1200s, and Airwavz RedZone Receiver RZR-1400s. All have their plusses and minuses.

The Airwavz RZR-1200 exposes many statistics from the tuner/demodulator and allows capture at the baseband packet level, enabling full analysis of the ATSC 3.0 payload by our stack. However the RZR-1200 is an early ATSC 3.0 device with a demodulator that struggles with dynamic multipath and weaker signals. Both the HDHomerun Connect 4K and Airwavz RZR-1400 sport the newer Sony ATSC 3.0 tuner/demodulator with rather good sensitivity and dynamic multipath performance. However the Sony tuner/demodulator processes the baseband packets internally and outputs ALP packets. As a result we don’t get a good idea of channel utilization (i.e. the actual PLP bitrate, as stuffing occurs at the baseband packet level.) The HDHomeruns also do not expose the level of tuner/demodulator information that the RZRs do. Lastly, while the HDHomeruns are more affordable than the RZRs and have two ATSC 3.0-capable tuners, we are currently experiencing stability issues where the Connect 4k will spontaneously unlock from 3.0 signal and fail to relock.

Q: Are you affiliated with any of the Bay Area broadcasters?
A: No. Koherence, LLC has a long history in working with consumer electronics companies, including in their development of DVRs and related devices. The OTA broadcast monitor is an outgrowth of Koherence’s internal tools used in the development and testing of these products. It’s been made publicly available in the hope that it is useful to the local broadcast engineering and enthusiast community.