KMTP-TV - TvTechnology

KMTP-TV

KMTP-TV has been a part of San Francisco broadcasting for 16 years, bringing ethnically diverse programming to its viewers as an independent public television
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KMTP-TV has been a part of San Francisco broadcasting for 16 years, bringing ethnically diverse programming to its viewers as an independent public television station. During this time, the station rented studio and office space and depended on equipment donations from local TV stations.

When the FCC mandated the transition to digital, KMTP was housed in the bottom floor of a one-time brewery, running with hand-me-down equipment and a 40-year-old analog transmitter. The station saw the digital transition as an opportunity to upgrade its entire operation, which included purchasing a new transmitter and a building of its own.

The planning stages

In 2004, KMTP installed new Thomson Grass Valley analog and digital transmitters at Sutro Tower. Fortunately, a community digital antenna system had already been installed in 1999, so this made the process a little easier. However, the station still had to fit the new transmitters in the same room as its existing GE UHF transmitter. The engineers cut a hole in the wall to the station next door and brought the cabinets and HVPS through it. They ran the DTV transmission line up to the roof and into the combiner building. Then they connected it to the mask filter, which was also installed in 1999.

It took time before KMTP could find a suitable and affordable building. Because of the technology downturn several years ago, the station found a building in the heart of Silicon Valley that fit its budget. The new building is located near Stanford University in the city of Palo Alto, about 30 miles south of San Francisco.

Its 21,000sq-ft space is more than enough room for the station's present needs. It even gives KMTP extra space, which allows the station to rent out sections of the facility to on-air clients. An added bonus is that the building includes two classrooms, which the broadcaster plans to use in the near future.

In order to stay within the budget, economy and simplicity were the primary goals of the design for the new facility. The new facility was a fresh start for the station, because most of its existing equipment would not be needed in the new facility.

The station decided that the new facility should be all-digital, using SDI, SMPTE 259M, video and AES/EBU balanced audio throughout, with any analog equipment converted directly to digital. KMTP wanted to start out with four SD digital channels, which required a fully automated, multichannel master control room that could be run by a small staff or left unattended at times. Because of the station's small staff size, it was decided that all tape ingest would be accomplished within the facility's master control, which meant putting all the VTRs within it.

The heart of the station's system includes three main components: the video servers, an automation system and a routing switcher. Each part is crucial to the success of the new multichannel facility.

Video servers

The first step was selecting the video server, which needed to have several output channels and at least two ingest channels. It also needed to be expandable to handle future growth. KMTP would have liked to build in HD capability, but it was outside of the station's budget. Therefore, the station decided to handle HD capability as a completely separate playout system in the future.

KMTP installed a Video Technics Apella video server because it has many of the functions and the expandability the station required. The server is based on a gigabit network. Digitized audio and video travel over the network from ingest to storage or storage to playout.

Storage is handled by a Ciprico DiMeda 1700 NAS server. If more space is needed, NAS can be easily added to the network.

The chassis hold a maximum of four playout/record channels. Each channel can be used for ingest or playback, and the chassis are connected to the network with just one cable. KMTP uses two chassis with a total of six channels.

The video server allows off-the-shelf PCs to run software that enables the station's staff to view any clip on the server and edit it as well as add voice-overs to any video clip. This feature is important to KMTP because the station produces foreign language news programs. It allows the station to add voice-overs to preproduced segments without using its limited number of edit bays.

A hot folder on the NAS allows the station's Final Cut Pro editors to drop completed files into it. Then the files are processed and placed on the video server automatically and ready to be played on-air. The same editors can also browse the contents of the NAS and pull files off of it.

Automation

KMTP was determined to find automation that was stable, reliable and backed by excellent customer service. The station selected a four-channel Crispin RapidPlayX 2000, which includes free lifetime support. In order to facilitate the marriage of the servers to the automation, Video Technics sent an Apella system to Crispin to ensure that the two systems would communicate to one another when the equipment arrived at the new facility.

Routing switcher

Lastly, KMTP needed a routing switcher to tie the system together. The station couldn't afford a dedicated master control switcher for each channel, so it decided that the routing switcher would act as its master control switcher. This obviously meant the station needed a reliable SD digital routing switcher that fit the budget.

KMTP went with a Sigma Electronics ADX router with 64 inputs and 32 outputs. It can be expanded up to 128 × 128, but even at its present size, the station will not use all of it for some time.

The station also purchased seven Sigma SYX control panels. The AES audio is balanced, and the facility uses ADC PPA3-14MKII26NS audio patch bays, as well as Belden1800A digital audio cable. The facility is outfitted with Switchcraft VPP26K3HD75T video patch bays and uses Belden 1694 digital video coax for SDI video cabling.

Monitoring

The new facility required all new monitoring equipment because the station switched to digital. Engineers installed four 17in Panasonic BTLH monitors, which handle SDI-HD, SDI-SD as well as analog inputs. The monitors come in a one-piece design, making them easy to mount.

The station's budget only allowed it to purchase one SDI waveform/vector scope rasterizer, so it installed a Leader LV7720. The main unit is mounted in the equipment room and uses a VGA splitter, another feed goes to master control where it is an input on a KVM switch at the dubbing position. The facility also includes a Sigma TSG490Y sync generator with SDI test patterns and AES test tones.

In master control, there are three work positions:

  • automation, where all four channels are controlled;
  • workstation, which gives the station access to the video servers and a place to create and edit playlists; and
  • dubbing, where VTR ingest is accomplished and clips can be transferred into the video servers.

The only equipment KMTP kept from its old facility was its Beta and U-Matic VTRs, which are mounted in the MCR racks for ease of use. The satellite receivers are also mounted in the MCR racks.

Contrary to the rest of the facility, monitoring in master control is mostly analog, which was done for purely budgetary reasons. Off-air monitoring of the station's DTV signal is accomplished through four Samsung DTB-H260F set-top boxes, each tuned to a different channel. The STBs are connected to Thomson Grass Valley 8550 audio DAs and Hedco VDA 100 video DAs, which in turn feed Tatung TLM1503 15in monitors, a Videotek RS12A analog switcher and Harris Leitch Panacea Lite Digital 12 × 1 switcher in master control. One digital router output is converted to analog and fed to the same switcher, which is then connected to a Magni WV560 analog waveform monitor and a Tatung V32GCGI 32in monitor/DTV receiver also in the MCR.

Encoding

The encoding system is comprised of four Harmonic MV45 SD encoders as part of an NMX statistical multiplexer. The system uses a GUI interface to monitor and control the encoding system, from tracing and recording faults such as a bad video input to changing the bandwidth priority of any channel. It is easy to use, and it can automatically switch in a spare encoder if one fails, as well as send an e-mail to let you know.

The output of the stat mux is connected to a Thomson Amber multiplexer, which is where the Program and System Information Protocol (PSIP) data is added to the transport stream. KMTP also uses the company's Pearl PSIP generator to create the PSIP data.

Computer networks

The technical room uses five different computer networks, not including the Internet. The station keeps all its IP address ranges separate for security purposes. All the network routers and switches are located in one rack to make it easier to monitor all the systems. This also allows engineers to patch any system to the Internet when remote access is needed.

Studio production equipment

For studio productions, KMTP purchased three Canon XLH1 camcorders, which double as studio and field cameras. They have genlock and SDI outputs so the station can use them in the studio.

The facility's Broadcast Pix 2000 production switcher features both analog and digital inputs and outputs as well as a DVE, built-in video clip playback and Inscriber TitleMotion DV V4.3.1 CG. The system can be controlled from its control panel or via the network browser.

The station's two classrooms will be used for equipment training. In addition, the classrooms may be used to teach classes in video engineering and production.

Russell Brown is a chief engineer for KMTP-TV.

Design team

VMI

Ron Wells, main supplier

KTMP-TV

Russell Brown, chief engineer

Doug Benson, Kelly Quan, Bianca Brown, Joy Brown, Phil Hartman, construction assistants

Technology at work

ADC PPA3-14MKII26NS audio patch bays

Belden
1800A digital audio cable
1694 digital video coax

Broadcast Pix 2000 production switcher

Canon XLH1 camcorders

Ciprico DiMeda 1700 NAS storage

Crispin RapidPlayX 2000 automation system

Harmonic
MV45 SD encoders
NMX statistical multiplexer

Harris Leitch Panacea Lite Digital 12 × 1 digital switcher

Inscriber TitleMotion DV V4.3.1 CG

Leader LV7720 rasterizer

Magni WV560 analog waveform monitor

Panasonic BTLH monitors

Samsung DTB-H260F set-top boxes

Sigma Electronics
ADX router
SYX control panels
TSG490Y sync generator

Switchcraft VPP series video patch bays

Tatung
TLM1503 15in monitors
V32GCGI 32in monitor/DTV reciever

Thomson Grass Valley
8550 audio DA
Amber multiplexer
CTT-U-50CXIC analog transmitter
CTT-U-DCX digital transmitter
Pearl PSIP generator

Video Technics Apella video server

Videotek RS12A analog switcher