We operate two transmitters from our facility here and use fiber to transmit program feeds to the STL. One feed is for WTLH, a Fox station licensed to Bainbridge, Ga. and the other is to our low power operation—WTLF, a CW station that's licensed to Tallahassee. WTLH operates both stations.
FIBER IS YOUR FRIEND IN LIGHTNING COUNTRY
The station and its associated STL building are about 350 feet apart, so I decided to install fiber between the two. This is a good a way to move SMPTE-310M to the STL and it keeps us protected from lightning strikes. I selected multimode fiber, as it's easy to splice and the run is fairly short.
I first learned about Ensemble Designs from TI Broadcast Solutions Group, an Atlanta-based systems integrator. We used them to do our fiber equipment installation between the two buildings. They installed Ensemble Designs' Avenue 3710 electrical to optical converters and 3720 optical to electrical converters. The 3710 and 3720 were designed for HD, SD and ASI signals.
Leading up to the project, I spoke with Mike Sauter at Ensemble Designs, and told him that I needed 3710's and 3720's that could pass a SMPTE-310M stream. I already had 310M installed in the STL building and wanted to keep everything 310 as much as possible. He said modifying the modules for 310M wasn't a big issue and they took care of it. That saved a lot of money, as another 310 to ASI converter wasn't needed.
Fox Television provides a rack for their network feed, and the output is an ASI stream containing the program material. We feed the ASI signal to an Ensemble Designs' Avenue 3710 electrical to optical converter and that signal then goes by fiber to the STL building. There, it's converted back to an electrical 310M signal by an Avenue 3720 and fed to the microwave system connecting the transmitter. The CW feed comes straight out of the mux as 310M and goes into the Avenue 3710. It too is sent to the STL building via fiber.
After the installation was completed, we had a lightning strike that took out another manufacturer's ASI/SMPTE converter, but the Avenue gear withstood the strike just fine.
If I do need assistance from Ensemble, Mike Sauter and the guys in the lab are always just a phone call away. It's nice not having to chase people by voice mail or leave messages.
At one point I thought I had a problem with the optical transmitter on an Avenue module and they asked me to return the card to the factory. After an examination, they returned it to me, along with a loaner laser level meter. I didn't have to fill out a PO, a loan agreement or any paperwork to use the meter. They just sent it to me with the understanding that I'd use it for a day or so to troubleshoot the problem and then send it back to them. This is service that you really don't expect to find any more. In this day and age, most other companies don't look out for you like that.
Nirmal Singh has been with the WTLH and WTLF engineering department since 2001 and is also an amateur radio operator. He may be contacted at firstname.lastname@example.org
For additional information, contact Ensemble Designs at 530.478.1830 or visit www.ensembledesigns.com