RF 7 is dead. Long live RF 7!

On the dot at 10 AM this morning KRON’s ATSC 1.0 emission on RF 7 went down. Almost instantaneously the 3.0 lighthouse came online.

Congratulations to all involved on a successful 3.0 launch!

Unlike our reception of RF 6 KBKF, the RF 7 lighthouse is bright and strong here in Mountain View. We’re watching The Price is Right in 3.0 via Project Entangle (which admittedly doesn’t offhand appear any better than 1.0…and trick playing HEVC really taxes things!)

For the techies of you out there, the emission has a single PLP using 256qam modulation and a 10/15 code rate. It carries roughly 28 Mbps of baseband packet payload. About 25 Mbps are accounted for in service/LLS bitrates (service bitrates are tallied as the sum of the UDP packet lengths received for a service). All six services utilize ROUTE/DASH (no MMTP services). The services are (at least presently) not encrypted (no A3SA).

Continue reading “RF 7 is dead. Long live RF 7!”

Where Has My 4.x Gone?

[Update 3/27 The migration of the 4.x channels to their new homes has occurred as of ~4:00 PM. Note that they are still broadcast on RF 7 as well (and likely to be there until the 3.0 cutover on the 29th).]

On March 29 RF 7 (KRON) will convert to an ATSC 3.0 lighthouse. ATSC 3.0 lighthouses allow partnering broadcasters in an area to continue to offer their programming via ATSC 1.0 while also rolling out an ATSC 3.0 version of their broadcast. One of the participating broadcasters allows their RF spectrum to be used for ATSC 3.0, which carries not only their main channel, but also the main channels of their partnering broadcasters (and occasionally some subchannels). In return the partnering broadcasters use their ATSC 1.0 broadcasts to carry the main (and select subchannels) that were previously on the lighthouse’s RF channel.

In the Bay Area KRON, KPIX, KGO, KTVU, KDTV, and KNTV are partnering to launch ATSC 3.0, with KRON (RF 7) as the lighthouse. The 4.x channels will be dispersed among the partner broadcasts.

Starting March 29 those of you without an ATSC 3.0 set (which is probably just about all of you!), can find RF 7’s current programming at:

  • 4-1 (KRON) will be carried by KTVU on RF 26 and RF 31.
  • 4-2 (Antenna TV) will be carried by KNTV on RF 13
  • 4-3 (Rewind) will be carried by KBCW on RF 28
  • 4-4 (Charge!) is currently carried by KBCW on RF 28
  • 4-5 (Shop TV) will be carried by KGO on RF 12

A rescan of the available channels will be required once the shuffling is done. Those of you using EPG (e.g. TiVo) won’t need to rescan but will need to wait until your EPG provider updates its channel list.

Continue reading “Where Has My 4.x Gone?”

NextGen TV (Finally!) Arriving in the Bay Area

Strictly speaking the Bay Area has had 3.0 for a while in the form of KBKF on RF 6. But like many of the 3.0 RF 6s KBKF is more of an experimental station demonstrating that ATSC 3.0 can share spectrum with FM radio (thanks to 3.0’s OFDM modulation scheme). KBKF presently carries Jewelry TV – not quite one would call a major offering.

Despite being hailed as the technology center of the US, the SF Bay Area seems to be late to the party when it comes to ATSC 3.0 (aka NextGen TV). Even Honolulu lit up with 3.0 last year! (Admittedly it may have provided some excuse for broadcast engineers to visit the islands…)

But it’s finally happening: the  major networks will arrive on 3.0 at the end of March.

Continue reading “NextGen TV (Finally!) Arriving in the Bay Area”

ATSC 3.0 Charts Are Back!

Though we’ve still only got the one RF-6  KBKF “frankenstation” in the (south) Bay Area, the 3.0 charts are back!

We’ve switched from a (pricey) Airwavz RZR-1200 to a (less pricey) HDHomerun Connect 4K Developer Edition.  The HDHomerun’s Sony demodulator is generally superior to the older LG demod in the RZR-1200 (the newer RZR-1400 also uses the Sony demod). That, and some antenna tweaking, seems to allow us to get a decent 3.0 signal.

We’re still working out some issues with software support for the HDHomerun. It has an annoying tendency to go offline from time to time. So don’t be surprised if the charts flatline occasionally. KBKF itself also seems to have some issues where it occasionally transmits only the bootstrap, or service-level signalling but no actual audiovisual streams. In these cases the tuner charts will continue to show some life but the bitrates and packets/s will drop to zero. Continue reading “ATSC 3.0 Charts Are Back!”

What’s up with the ATSC 3.0 charts?

Some of you have been wondering what’s happened to the ATSC 3.0 charts. Sad to say, our reception of KBKF is quite challenged here. The vast majority of the time we have a very impaired or no signal, so the 3.0 monitor has been retasked for other NextGen TV-related projects.

We’ll bring it back once we’re able to get a decent signal. Or, if any of you further south and able to receive KBKF would like to host it, drop us a note. We’ll gladly provide the monitor if you provide electricity and internet!

NextGen TV Arrives in the Bay Area!

It was a bit unexpected. And the programming isn’t exactly a showcase of what NextGen TV can deliver. But at long last the Bay Area has an ATSC 3.0 (aka NextGen TV) broadcast compliments of KBKF! After spending a couple years trekking to Phoenix, Santa Barbara and Las Vegas to go to the emissions it’s nice to have one in our own backyard. And we’re pleased to add ATSC 3.0 monitoring support at SFBayATSC!

KBKF is operated by Venture Technologies Group, LLC and broadcasts on VHF 6 from Loma Prieta. At the time of writing the 3.0 emission consists of a single PLP utilizing 64 QAM and an 8/15 code rate. This is a bit more robust than other 3.0 emissions, which often utilize 256 QAM, though at the expense of a lower capacity (~14 Mbit/s). In mid June two ROUTE/DASH services were being transmitted – a barker channel as 6-1 and UChan as 6-2. At the moment UChan has taken the 6-1 VC and the barker has signed off. Interestingly the services are using AAC audio. While this was prevalent in early 3.0 phases when AC-4 support for receivers and encoders was still under development, commercial deployments in the US use AC-4. (The ATSC 3.0 specification provides for multiple audio codecs, but only a single codec is allowed in a region. In North America that codec is AC-4.)
Continue reading “NextGen TV Arrives in the Bay Area!”

Spectrum Repack Complete

The spectrum repack reduced the frequencies used for over-the-air television to channels 2 – 36 to make room for other services such as 5G wireless. As a result of the repack stations broadcasting on channels above 36 moved to lower frequencies. Some stations that were broadcasting at channel 36 or below also moved broadcast frequencies, and some stations ceased operation.

Read on for the timeline for the SF Bay Area repack and additional information regarding the repack.

Continue reading “Spectrum Repack Complete”

Maintenance History

  • 20240321 – The RF distribution has been redone for the main Sutro Tower feed. Two CM-3418s that were cascaded have been replaced with a single Leviton 47693-16P. This should result in a marginal improvement in signal quality although the actual signal strength my appear diminished due to reduced amplification (the Leviton provides unity gain (+0 dB) at each output while the 3418s were +3.5dB per output). The reduced strength is most noticeable on RF 21 and RF 13 and reflects a weak signal at the antenna, although the signal quality (as evaluated by the demodulator) remains unchanged.
  • 20230324 – The site has gotten a facelift in preparation for the RF 7 lighthouse coming online. Please let us know if you run into any issues.
  • 20230314 – The recent storms have been wreaking havoc on the main antenna receiving from Sutro Tower and San Bruno Mountain. Impairments across multiple Sutro/San Bruno channels likely means we haven’t had a chance to re-orient the antenna and not a problem with the broadcasts.
  • 20210628 – A Winegard HD7000R has been added as the Loma Prieta feed, and RF 6 (ATSC 3.0 KBKF) has been added on that feed.
  • 20210321 – RF 19 (KSTS) has been added to the Fremont feed.
  • 20210321 00:30 – 02:00 – Maintenance – hardware upgrade.
  • 20200728 – RF 34 (KFSF, KDTV) has been added on the Sutro Tower feed.

Continue reading “Maintenance History”