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.

14 thoughts on “Studio Buildout, Part II”

  1. It all looks nice but you should move that 5.8 GHz dish all the way to the top of the mast in order to get your fresnel zone clearance over the parapet wall.

  2. Mike, the shadow makes the parapet look taller than it actually is. There is plenty of room to slide the dish up a little if needed. Fresnel zone clearance here should be relatively easy (copy pasta from Wikipedia):

    The general equation for calculating the Fresnel zone radius at any point P in between the endpoints of the link is the following:

    Fn = sqrt(n\lambda d1 x d2)/(d1 + d2)


    Fn = The nth Fresnel Zone radius in metres

    d1 = The distance of P from one end in metres

    d2 = The distance of P from the other end in metres

    \lambda = The wavelength of the transmitted signal in metres

    So, total path distance is 5,435 meters making D1= 4.65 meters and D2 = 5,430.35 meters.

    Frequency is 5.8 GHz making the wavelength 0.0517 meters.

    Thus first Fresnel zone clearance at the parapet wall: Fn = sqrt(0.0517m x 4.65m x 5,430.35m) / (4.65m + 5,430.35m)

    Fn = 0.49 meters or 19.29 inches. Parapet wall is 18 inches (0.453m) tall, so 18in + 19.29in = 37.29in (0.947m) minimum required antenna height for F1 clearance.

    Yup, looks like that antenna is going to have to go up a few more inches to make F1.

  3. Very nice looking!

    Starting to plan an new studio build out, curious as to what you are use for KVM extenders.

  4. We got about 2 years out of those sandbags then had to replace them with cinder blocks. NPRM holding up a 3.8 meter dish…fun, fun.

    Prewiring that transfer switch and plug is brilliant. I wish more sites had that.

  5. Someone used bags of pre-mixed concrete as ballasts on a sat dish. The idea was that normal rain would soak it & set it up. Then they covered the ballast with metal sheets. Years later there was only some gravel left.

  6. What is it with broadcasters using 5.8ghz for STL… personally I think your playing with fire for the following reasons:
    1) its only a matter of time before 5.8ghz becomes a complete mess like 2.4ghz is now.
    2) Its a free band so anybody can come along and jam you up and there isnt anything you can do about it (e.g bring up a 40mhz unmodulated carrier and your dead in the water)

    I mean seriously.. would you run your taxi/courier business on CB radio? because thats basically what your doing!

  7. 5.8 GHz as an STL works fine if sufficient antenna gain is used to overcome interference. The choice of bandwidth and modulation also matters. (if the equipment allows)

    I began using 5.8 GHz to extend the LAN to the transmitter site in 2002. The path is 13 miles long, the dishes are 6′ and 4′. The equipment was Western Multiplex, (now Proxim). They use 25 MHz bandwidth and QPSK modulation. The path never failed.

    In 2003 we used 5.8 GHz on a 35 mile SD video path using 8′ and 10′ dishes. There was only one 5 minute long rain fade. Again Proxim gear. No interference ever. To make sure we used VLAN capable switches.

    In 2007 we deployed HD video at 35 mb/s over IP on a 13 mile path using 8′ and 3′ dishes. This was for a news bureau. The video is now on 7 GHz, but the path continues to be used for transferring large video files. Over the years it needed to be moved in frequency once, as the 3′ dish was not entirely adequate on top of a downtown Albany office building. This uses Harris Velox equipment at 45 mb/s and VLAN gear.

  8. Very nice install at this point!. Love reading your posts on your radio engineering. Keep up the good work and posts. Gives me ideas when taking care of 5 stations.

  9. TRENDnet AU presented: TRENDnet’s KVM Expansion Kit, design TK-EX4, expands keypad, video, and mouse handles for ranges of as high as 100m over Cat5E or even Cat6 Ethernet wire . No need any software setup – simply network the sender unit and also receiver for complete KVM maintains. Eradicate the time that is necessary to walkway to the exposure area by enlarging KVM handles to your won study place.

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