Studio Buildout, Part II

Some pictures of the studio build out in progress.

Counter top mounted
Counter top mounted

This is the counter top, mounted on a riser with the wire way cut into it. These counter tops will have AudioArts Air4 consoles installed on them.

AudioArts Air4 console with microphones
AudioArts Air4 console with microphones

Studio is taking shape. Console mounted with microphones. The rack mounted equipment goes in the Middle Atlantic rack under the counter top to the left of the console.  That rack is on casters so it rolls out to get access to the back of the equipment.  We have pretty much done away with cart pods or other counter top equipment housings.  The automation and other computers will be mounted in the rack room and extended to the studio with IP KVM extenders.

Sub Panel with manual transfer switch
Sub Panel with manual transfer switch

We installed a small Square D sub panel and manual transfer switch. This is to prevent the “Space Heater” outages, you know, when the morning show guy plugs a space heater into the same circuit as the console or computer, trips the breaker, then calls you because they are off the air. Yeah, good times.

In addition, the manual transfer switch will allow them to use a good portable generator if there is a prolonged power outage. On the bottom of the switch I installed a 30 amp twist lock input receptacle.

Since the building is older, the grounding buss was installed and wired directly to the ground at the service entrance panel.   The building sub panel for this floor is using conduit for the ground conductor back to the service entrance panel, which used to be code compliant but no longer.

5.8 GHz dish with non-penetrating roof mount
5.8 GHz dish with non-penetrating roof mount

STL/LAN extension dish installed on roof top. I used an old non-penetrating roof mount for a four foot satellite dish.  The building owner was very specific about not having anything puncture the new rubber membrane roof.  Thus, the heavy rubber mats and sand bags instead of cinder blocks.  These stations will be using a Cambium PTP-250 system for STL/TSL and LAN extension. This will haul program audio for five radio stations plus satellite backhaul and remote control. It is a relatively short path with the FM tower visible from the roof top.

5.8 GHz path to FM tower
5.8 GHz path to FM tower

It was kind of hazy when I took this picture, but if you look really close, you can see the FM tower out there on the hill top.  The path is 3.37 miles (5.43 KM).  With a 40 MHz channel width, that should net about 175 Mbps bi-directionally, which is more than enough to do what we want.  This set up will require a pair of managed switches and some VLAN configuration, which I will post separately.

Studio Buildout, Part I

We are in the process of building a couple of new studios for one of our clients. This one involves a small market combo of one AM and four FM stations.  These stations were formerly located at one of the transmitter sites, two miles outside of town on top of a large hill.  That site could be difficult to get to during the winter and the building itself was not in the best of shape.  Thus, plans were made to move the studios to a better location.  Fortunately, we discovered that right in the village there are several suitable office buildings.

Any worthwhile project needs to be planned for.  The first consideration is the Studio to Transmitter Link (STL) paths.  Since this is a radio studio, it makes sense to located it where viable RF STL paths exist.  One might be surprised by the number times the issue of bad or non-existent RF STL paths has come up during these types of projects.

Studio to transmitter site LAN extension
Studio to transmitter site LAN extension

The next thing to check is the satellite path.  The plan right now is to keep the satellite dishes at the transmitter site, however, at some point in the future we can relocated the satellite dish to the roof of the studio building if desired.

AMC-8 satellite path
AMC-9 satellite path

The floor space was measured out and I drew out a floor plan:

Walton Studio floor plan
Walton Studio floor plan

Before we started work, all of the walls were painted and new carpeting installed.

Almost nothing at the old studio is worth keeping. Thus, all of the furniture, consoles, racks, STLs, and other equipment needed to be ordered.  A local kitchen company traded out the counter tops, which we picked up at their facility and delivered to the studio ourselves.

Studio counter top
Studio counter top

We will build risers for these on site then mount the consoles and such.

New Studio Equipment
New Studio Equipment

In the mean time, most of the new studio equipment has been ordered and delivered. There are still some outstanding items that have not arrived, but I am assured that those are in process and should be showing up shortly.

Used equipment racks
Used equipment racks

These equipment racks came from another market, but are in good shape.

I had a good meeting with the building owner regarding roof access, a sub panel for the racks and studios and other issues.

The Isolated Ground

We get requests to install Isolated Ground outlets from time to time, especially with sensitive equipment. The TELCO likes to have isolated grounds on their fiber MUX’s.  It can become an issue with branch circuits in split phase or three phase services that share the same ground and neutral conductor.  This can lead to a ground loop between neutral and ground, which will create all sorts of havoc in a broadcast facility.

20 amp, 120 volt Isolated Ground Outlet
20 amp, 120 volt, Isolated Ground Outlet

The National Electrical Code covers Isolated Grounds (IG) and sensitive equipment in several sections.  The first is section 250.146(D), which states that installation of isolated ground receptacles is permitted.   The grounding conductor connected to such receptacles is permitted to pass through one or more panel boards, boxes, conduit bodies, etc without being bonded to them.  However, said panel boards, metallic boxes, conduit bodies, raceway, etc must also be grounded separately.  That means running two ground conductors, usually the isolated ground conductor is green with a yellow stripe or spiral.

Studio electrical diagram isolated ground
Studio electrical diagram isolated ground

The second is section 640.9(A), which refers to separately derived power systems.  This section deals specifically with balanced power; 60 volts AC to ground.  In such cases, a separate ground conductor is allowed as outlined in section 250.146(D) and in 647.6(B), which states that the grounding buss should be connected to the grounded conductor on the line side of the separately derived systems disconnecting means.

Other sections of the NEC that may apply to broadcast radio and television facilities:

  • Article 455, Phase converters (rotary phase converters)
  • Article 480, Storage batteries (UPS)
  • Article 520, Theaters, Audience Areas of Motion picture and Television studios, Performance areas and similar locations
  • Article 640, Audio signal processing, Amplification and Reproduction Equipment (Audio wiring)
  • Article 645, Information Technology Equipment (computer equipment and network wiring)
  • Article 647, Sensitive Electronics Equipment (balanced power 60 volts to ground)
  • Article 702, Optional Standby systems (generators)
  • Article 770, Fiber optic cables
  • Article 810, Radio and Television Equipment (antennas, towers and grounding)
  • Article 820, Cable TV (CATV)
  • Article 830, Network-powered broadband communications systems (power over ethernet)

If interested, I can do articles on these sections as well.