Review: ZvBox 150 QAM Modulator

Despite running a bit warm, the ZvBox 150 upgrades signal quality without disruption of existing wire infrastructure.

The ZvBox 150 modulated signal looked good. Blacks were black, focus was good, action flowed smoothly, and I didn’t see any annoying video artifacts.

By Fred Harding
February 25, 2010

Years ago, custom installers worked with modulators to convert base band video signals to NTSC television channels. Manufacturers like Channel Plus, Pico Macom, Channel Vision, Blonder Tongue and others made a variety of options in this category.

Installers would use these devices to make security cameras, VCRs, satellite boxes and other sources available to any television on an unused channel.

With the advent of the ATSC changeover, NTSC modulators have lost some of their luster. The picture quality difference between a modulated NTSC channel and an ATSC channel is fairly noticeable to even the most casual observer.

The challenge for installers who needed the ability to send high-definition video signals around a home or commercial installation was met, in part, by the application of Component video matrix switches. The complication with those was that you needed to size the switch according to the number of inputs (sources) as well as the number of outputs (displays that would show the image).

Another downside to matrix switchers is the necessity for cabling to support the system. If I’m working in an older, finished residence, or updating a sports bar, I need to consider the amount of time and effort pulling appropriate cabling from the headend to each display.

The ZeeVee ZvBox 150 allows me to go in to a facility and upgrade picture quality with little or no disruption to the existing wire infrastructure. In a sports bar, that means you can install the product without having to work through the night. In a residence, you don’t have to do extensive wire pulls to all the displays.

ZeeVee is a comparatively new company to the marketplace, but it has captured a portion of the market with its QAM modulator products. Other manufacturers are making similar products, but ZeeVee is offering their device at a fraction of the cost of the more industrial alternatives.

The ZvBox 150 is one of several modulators the company offers. There is a model 100, which only modulates VGA signals. The model 250 is more of a commercial option that modulates either VGA or Component video. The model 150 also offers the ability to modulate component or VGA signals to a 720P QAM channel.

Set-up

The 150 is set up using a laptop. I hooked up a Blu-ray player via component outputs into the 150. I connected the RF output into the cable network, and connected my laptop to the 150 via USB.

Software for programming is available at no charge from ZeeVee. I’d strongly recommend downloading the latest firmware prior to set-up. It also has links to updates, documentation and tutorials.

Once the programming software was loaded onto my PC and the connections were made, I went to the spectrum analyzer, which allowed me to scan for available frequencies to modulate on. I was able set up the channel I wanted to modulate on, as well as adjust the amount of signal in dB the unit was outputting. The amplifier is adjustable from 25 dB down to 0 dB in 5 dB increments.

The 150 comes with a channel 125 filter to assure yourself a clean frequency if the spectrum analyzer indicates you need one.-->

I set the ZvBox 150 up using a Blu-ray via component video and into the tuner of a 42-inch Panasonic 1080p display. I took an HDMI connection from the same machine and ran it into the same model of 42-inch Panasonic 1080p display. I played with color adjustments to get the levels eyeball close and then loaded “The Italian Job” to compare.

The HDMI connection clearly was better in the side-by-side comparison. I wasn’t astonished by that. What I was thrilled with was how good the modulated signal looked; blacks were black, focus was good, action flowed smoothly, and I didn’t see any annoying video artifacts. It was not a 1080p signal, but it was looking very good.

Monitor the Heat

After a couple of hours of working with the product, I discovered something every installer must know: this device runs very, very warm. The entire chassis acts as a heat sink, and this baby runs hot. Installers should install optional ventilation fans with each unit and provide plenty of space. This is not a product that should live in a sealed cabinet.

Other attributes of this model to keep in mind:

It modulates a QAM cable channel
It the display to have a built-in QAM tuner
It will not allow you to modulate on an off-air channel. If your installation wants to modulate one or two channels and work with off air signals, you’ll need to insert a tuner at the display end to decode the QAM signal and run the output of that QAM tuner into the display via a video input

The ZvBox 150 only accepts a digital audio input. If your video source only has an analog audio output, you’ll need to insert an analog-to-digital converter into the system to provide sound with the picture. Fortunately, there are devices that perform that task from Gefen and others that are moderately priced.

When modulating, you will want to pay attention to signal levels, just as you had to back in the NTSC days. A general rule of thumb to follow is that a two-way splitter knocks off 4 dB of signal; a four-way splitter 8 dB, and an eight-way splitter 12 dB. Signal also is attenuated over distance, and so long runs need to have that factored in as well.

Aside from the heat, I was very pleased with the performance of this unit. Make sure you ventilate the equipment rack, and you’ll be thrilled with the results.

Editor's note: Fred Harding works for Capitol Sales, which distributes ZeeVee products.

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