Another small market build out

Finishing up another studio build out in an unrated market. There are some engineers who think that small market work is beneath them. That is fine with me, I enjoy it.  Once again, creating a nice, functional, modern facility while not breaking the bank poses some challenges.   I like to take sort of a minimalist simple approach while not compromising good engineering practice.  Another challenge is rebuilding an existing facility.  Each studio needed to be demoed one at a time with the stations playing hop scotch from studio to studio around the work.  There were four studios total plus the rack room.  There were also several other renovations going on at the same time as this project.

Looking at the overall facility, the client decided that one studio would be the main room where multiple guests could be seated, etc.  The other rooms would have guest microphones, but they are smaller rooms and limited to one guest each.  The smaller rooms have AudioArts Air4 consoles while the main studio has an R-55e.

WZOZ console, main studio, Oneonta, N
WZOZ console, main studio (Studio A), Oneonta, NY

The main studio had existing studio furniture that was in reasonable shape so we decided to reuse it.  While we had the studio ripped apart, the paint and carpet where updated.  The main microphone is an Electrovoice RE-20, the guest mics are Heil PR-20UT which are inexpensive and have excellent characteristics for a dynamic microphone.  Since this faces a fairly busy street, I put in some very basic DBX 286S mic processors with a little bit of downward expansion.  Adobe Audition is used for production.  I have also used Audacity which is available in both Windows and Linux flavors.  Acoustical wall treatments are coming soon.

Main studio, Oneonta, NY
Main studio, Oneonta, NY

The counter tops in the smaller studios were traded out with a local kitchen supply company.  We used Middle Atlantic BRK-12-22 racks with castors on them to install a limited amount of rack equipment.  Each one of these studios is nearly identical; a AudioArts Air4 console with JBL powered monitors.  The microphones in these studios are Heil PR-20UT with console supplied mic preamps.  These studios are used for WSRK, WDOS, WBKT and WKXZ.  All studios are off line when in automation, which means each can be used for production and other purposes.

Studios B-E, Oneonta NY
Studios B, Oneonta NY
Studio C, (WDOS) Oneonta, NY
Studio C, (WDOS) Oneonta, NY
Studio D, (WSRK) Oneonta, NY
Studio D, (WSRK) Oneonta, NY.

We started the TOC from scratch. This area was occupied by a bunch of empty file cabinets previously. The original equipment racks where in Studio A.

A riser was installed from the racks straight up to the roof for the STL, monitor antenna and satellite dish transmission lines.  Everything is grounded with a star grounding system connected to the main building ground which consists of driven ground rods and the water main.  The STLs have Polyphaser IS-PT50HN lightning protection devices installed.

900 MHz lightning protectors on STL transmission lines
900 MHz lightning protectors on STL transmission lines

The racks are Middle Atlantic MRK 4031.  Since this building was built sometime in the mid 1800’s, the floors are a bit uneven (along with almost everything else), so a fair amount of shimming and leveling was needed to get these units bolted together.

Racks and equipment
Racks and equipment

Each rack has its own UPS in the bottom and they are all on separate breakers.

A manual transfer switch controls a dedicated electrical sub panel.  All of the racks and studios are powered from this sub panel.  Below the transfer switch is a NEMA L14-30 twist lock male receptacle for generator connections.

Studio/TOC sub panel and transfer switch
Studio/TOC sub panel and transfer switch

The total load about 18 amps.  The station is looking to trade out some generators for various transmitter sites.  I suggested that they get a couple of the portable Honda inverter generators, which are very good have excellent power regulation, frequency stabilization and fuel economy.

The existing Scott’s Studio 32 system was updated with new computers.  This is an interim step until a new automation system can be installed next year.  Each station has it’s own BT 8.2ss switcher which can select any studio to go on the air with.  That flexibility makes moving from studio to studio easy.  It also allows for all the stations to be simulcast, which is handy in the event of an emergency.

Punch blocks are mounted on plywood attached to the back wall.  We left extra space for a new phone system.

The EAS monitor assignments are met with roof top yagi antennas.  I like drawings and diagrams, as the saying goes, a picture is worth a thousand words.  This is an image I created on Google Maps using the transmitter site coordinates for each of the EAS monitoring assignments.  That gives me good local aiming points for the various antennas needed.

EAS monitor assignment headings
EAS monitor assignment headings

Other drawings include a floor plan and block diagrams for each station.  I have a Viso template that I use for these.  I find that having these diagrams on hand in a book is very helpful in the event that somebody else needs to go to this station to work on things.

Block diagram for WDOS, Oneonta, NY
Block diagram for WDOS, Oneonta, NY

Finally, the wiring documentation which shows where each wire originates and terminates. Again, if I am not available and somebody else needs to do work here, this is very helpful. All the studios are laid out the same, so figure out one and then the rest falls into place.

Screen shot of wire run spreadsheet
Screen shot of wire run spreadsheet

There is still a little bit of clean up left and some old equipment to get rid of.  Otherwise, it’s a wrap.

Studio Buildout, Part III

I have been so busy that I forgot to post the pictures of the completed studio build out.  Overall, I would say that I am pretty pleased with the end result.  Of course, this is not Manhattan but rather an unrated market in central New York, and the budget reflected that.  Overall, the radio stations are in much better technical condition than before.  They are now located in the center of their community within walking distance of the town hall, other civic locations and activities.

There are five radio stations broadcasting from this new studio space.  Two stations are simulcast using the Westwood One Classic hits format from the satellite.  The only AM station is a Fox Sports Radio affiliate from the satellite with a local morning show.  Another one is a “we play anything” computer juke box and final station has a country format with quite a bit of local content.  Any station can go on the air from either studio.  In addition, all stations can simulcast the mother ship from Oneonta, which comes down via a Barix Exstreamer 1000.

Walton TOC

The Technical Operation Center consists of four racks containing the Ethernet routers, switches, a patch panel, automation systems, audio routing switchers, air monitor receivers, audio distribution amps, Barix units, Wheatstone Blade IP 88A STL, etc.  The equipment racks came from a disused site in New Jersey.

The satellite dish and receivers are located at the transmitter site, audio and closures come back via the Wheatstone Blade IP 88A.

Everything in this room is backed up by a STACO 2.5 KVA UPS.

TOC wire terminations

The wire termination from the studio are mounted to Krone LSA-PLUS blocks.  Studio trunk wiring consists of connectorized 25 pair CAT 5 cable.  There are also six runs of shielded CAT 5e cable for Ethernet and extended KVM from the TOC.

There is a manual transfer switch with a NEMA L14-30 input receptacle on the bottom.  A twenty for 10/4 SOJ cable will reach the ground from the window in the left hand side of the picture.  This is the standard NEMA plug/receptacle set for a moderate sized portable generator.  That feeds a 100 Amp sub panel which in turn feeds the racks and studio equipment.  Thus the entire facility can be run on a 5000 watt (good quality) portable generator in the event of a prolonged power outage.

The ground buss bar is connected to the main building ground at the service entrance.  All racks and studio consoles are grounded to this main ground point.

The air monitor receivers feed both studios.  There is also a provision to connect audio silence sensors up to each air monitor DA to notify the station staff in the event of an off air situation.  Believe it or not, this type of system has never been installed for these stations.

Studio A is the main studio.  The AudioArts Air4 console is a good fit for this type of operation.  These consoles have USB outputs, so the console can act as a sound card for the digital editing computer.  Each studio is equipped with an air monitor switch that can select any station to feed the external monitor input on the Air 4 console.  This allows the guy on duty to keep an eye on all the signals coming from the facility.

Studio A

The counter tops were custom made at a local kitchen place on trade. The microphone are Heil PR-22 with shock mounts, which are better than the Realistic mics in the old studio.  This is the first time that the main studio has had more than one microphone. The morning show guy has already pressed those guest mics into service with a few on air interviews.

The monitor speakers are JBL LSR305 mounted on home made speaker stands consisting of 18 inch black iron pipe and floor flanges.

Studio A

The small equipment rack is on casters and can roll out from under the studio furniture to get at the back of the equipment.  A used Gentner DH3 TELCO hybrid is used to get phone callers on the air.  Adobe Audition is used for editing and production on the left hand computer monitor.  That CPU is in the bottom of the roll around rack.

Studio A

The office chair and other furniture was also acquired on trade.

Studio A

What the operator sees. STORQ computer on the left for music, Scotts SS32 on the right for automation. Both are extended from the TOC. Unless the morning show guy is live on the air, the console is bypassed and the audio stays in the TOC.

It all works pretty well.

Studio B

Studio B is the same as Studio A except fewer microphones.

Studio B

Studio B operator view.  This studio can be used for one of the other stations or production.

Again, this is not a Fancy Nancy installation, but it does get the job done.

Part 101, Private Fixed Microwave Service

I have been tasked with installing one of these systems for a sixteen channel bi-directional STL.  This system was first mentioned here: The 16 channel bi-directional STL system.  As some of you pointed out, the unlicensed 5.8 GHz IP WLAN extension was the weak link in this system.  It was not an interference issue, however, which was creating the problems.  The problem was with layer two transparency in the TCP/IP stack.  Something about those Cambium PTP-250s that the Wheatstone Blade hardware did not like and that created all sorts of noise issues in the audio.   We installed the Wheatstone Edge Routers, which took care of the noise issue at the cost of latency.  It was decided to go ahead and install a licensed link instead of the license free stuff as a permanent solution.

Thus, a Cambium PTP-820S point-to-point microwave system was purchased and licensed.  The coordination and licensing took about three months to complete.  We also had to make several changes to our network architecture to accommodate the new system.  The PTP-820 series has a mast mounted radio head, which is the same as the PTP-250 gear.  However, for the new system, we used three different ports on the radio to interface with our other equipment instead of the single port PTP-250 system.  The first is the power port, which takes 48 VDC via a separate power cable instead of POE.  Then there is the traffic port, which which uses Multi-Mode fiber.  Finally, there is the management port, which is 1GB Ethernet and the only way to get into the web interface.  The traffic port creates a completely transparent Ethernet bridge, thus eliminating all of the layer two problems previously encountered.  We needed to install fiber tranceivers in the Cisco 2900 series switches and get those turned up by the IT wizards in the corporate IT department.

Andrew VLHP-2-11W 11 GHz microwave antenna
Andrew VHLP-2-11W 11 GHz microwave antenna

The radios mount directly to the back of the 24 inch 11 GHz Andrew antenna (VHLP2-11) with a UBR100 interface.  The wave guide from the radios is a little bit deceptive looking, but I tried not to over think this too much.  I was careful to use the O ring grease and conductive paste exactly where and when specified.  In the end, it all seemed to be right.

Cambium PTP-820S mounted on antenna
Cambium PTP-820S mounted on Andrew antenna

Not wanting to waste time and money, I decided to do a back to back test in the conference room to make sure everything worked right and I had adequately familiarized myself with the ins and outs of the web interface on the Cambium PTP-820 radios.  Once that was done, it was time to call the tower company.

Cambium PTP-820S on studio roof
Cambium PTP-820S on studio roof

One side of these are mounted on the studio building roof, which is a leased space.  I posted RF warning signs around the antennas because the system ERP is 57.7 dBm, which translates to 590 watts at 11 GHz.  I don’t want to fry anybody’s insides, that would be bad.  The roof top installation involved pulling the MM fiber and power cable through a 1 1/4 inch EMT conduit to the roof.  Some running back and forth, but not terrible work.  I used the existing Ethernet cable for the management port.  This will be left disconnected from the switch most of the time.

Cambium PTP-280S 11 GHz licensed microwave mounted on a skirted AM tower
Cambium PTP-280S 11 GHz licensed microwave mounted on a skirted AM tower

The other side is mounted at about 85 feet AGL on a hot AM tower.  I like the use of fiber here, even though the tower is skirted, the AM station runs 5,000 watts during the daytime.  We made sure the power cables and Ethernet cables had lighting protectors at the top of the run near the dish and at the bottom of the tower as well as in the transmitter room rack.  I know this tower gets struck by lightning often as it is the highest point around for miles.

PTP-820S RSL during aiming process
PTP-820S RSL during aiming process

Aligning the two dishes was a degree of difficulty greater than the 5.8 GHz units.  The path tolerances are very tight, so the dishes on each end needed to be adjusted in small increments until the best signal level was achieved.  The tower crew was experienced with this and they started by panning the dish to the side until the first side lobe was found.  This ensured that the dish was on the main lobe and we were not chasing our tails.  In the end we achieved a -38 dBm RSL, the path predicted RSL was -36 dBm so close enough.  This means the system has a 25 dB fade margin, which should be more than adequate.  While were were aligning the transmitter site dish, a brief snow squall blew through causing a white out and the signal to drop by about 2 dB.  It was kind of cool seeing this happen in real time, however, strangely enough, the tower crew was not impressed by this at all.  Odd fellows, those are.

Currently brushing up on FCC part 101 rules, part C and H.  It is always good to know the regulatory requirements of any system I am responsible for.  As AOIP equipment becomes more main stream, I see many of these type installations happening for various clients.