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Blue Valley Technologies - TechTalk

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HDTV Antenna comparison: Winegard SquareShooter vs Channel Master 3010 Stealth vs RCA Ant 806

Selecting the best antenna for receiving off-air HDTV broadcasts for your location can include several factors. One of those factors is how well do some of the various models pick up the signals in your location. Some locations may easily receive all the signals you are interested in with almost any antenna, while others may need a very high quality antenna with an amplifier. This article takes a look at three widely available antenna's, and compares how they stacked up at my location.

The three Indoor / Outdoor antennas reviewed here were provided by Advanced Satellite Communications located in Columbus, Ohio.

HDTV Off-Air Antennas

HDTV Antenna's usually include VHF and UHF elements. VHF elements are important for receiving channels between 2 and 13, whereas UHF elements receive channel frequency 14 and higher. Though it is important to note that in digital tv, the "virtual" channel number (e.g. 6.1) can actually be broadcast on a different frequency, often times in the UHF band (e.g. 38). To help sort this out, I recommend you look up the local broadcast information for your area using antennaweb.org. They will list the virtual channel as well as the actual frequency for the local stations in your area.

Antenna Web chart for my area.

All the models reviewed here were individually placed in the same location in a window on a second story home. The were pointed so that they received the best overall signal reception and that not moved or adjusted for each individual channel. I have also included the local reception using a Terk Indoor only amplified HDTV Antenna in the same position. This is to establish a baseline and demonstrate how much better reception an indoor/outdoor antenna can be. The Antenna I used is regarded as a good quality indoor antenna, but as you will see did not work nearly as well for my location as the larger indoor/outdoor models. The signal strength readings were taken with a Samsung SlimFit HDTV.

HDTV Measured Signal Strength Chart

Tested reception rating for all tested HDTV antenna's in this comparison.The Channel Master 3010 StealthTenna is marketed as a short range antenna that can receive analog and digital UHF, VHF and FM broadcasts. Although it s the least expensive model reviewed here (found online at several vendors for $39.99), it was the best performer in the un-amplified mode of any reviewed here. It did not include an amplifier with this model, and was only beat in reception by the WineGard Squareshooter in the amplified mode. This antenna was impressive that it actually outperformed the amplified RCA model. This is also the only model reviewed here that has external metal fins as part of the elements. While they certainly look more modern then the old metal elements that used to be prevalent on rooftops, they still may not meet the cosmetic requirements of some homeowners.

The mid-priced model reviewed here was the RCA Indoor Outdoor Ant 806 which can be found online from $50 - $89.99. This model includes an amplifier that can be connected to the output. I measured the reception in both modes, and found the amplifier did slightly increase the reception on some stations, but it actually seemed to reduce the signal strength on others. This antenna really didn't seem to perfomr any better then then indoor only Terk. Where this model shines is in the mounting options and cosmetic appearance. Although it is nearly 4 feet wide, the unit can be mounted underneath eaves, on railings, or even to the wall above your tv and not look too bad.

The Winegard SquareShooter SS-2000 is the most expensive model reviewed here, available online from a few vendors for $98. It also had the best reception, and had the highest quality feel and build-quality. The unit included a mini-dish style foot mount, and also had hardware for mounting to a pole. The unit included an optional amplifier as well. The amplifier was the nicest of any reviewed here. The AC adapter to power the amplifier is connected using a length of RG-6 coax cable. The advantage to this is that if you wanted to place the amplifier where there is not an available power outlet, such as in an attic, all you had to to is run a longer coax cable to an outlet anywhere else in the home. The Winegard also has a modern look that is likely to satisfy most homeowners and neighborhood associations.

Winegard Inline Amplifier

Posted by Mark at 21:04
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Conventional or 70V Commercial Speaker Systems: Which is the right choice?

Many small venues such as bars, restaurants, schools, and churches use a commercial speaker wiring format known as 70V. This wiring format has a higher signal voltage that allows for many advantages. Let's take a look at the differences, how it works, and how to decide which format is best for your application.

A conventional speaker system has one or more speakers that typically have an impedance of 8 Ohms, but 4, and 16 Ohm speakers are common as well. The impedance is similar to resistance, and can be used to determine how much load a speaker will put on an amplifier. A quality amplifier will list what the allowed range of load impedance is and what the maximum output will be at various loads. For example, an amplifier may list that it can handle speaker configurations between 4 and 16 Ohms. Hooking up any speaker configuration that places a load that is outside this range can cause damage to the amplifier.

The amplifier in our example states that its maximum output will be 200 Watts at an 8-Ohm load and 600 Watts at a 4-Ohm load. As you can see, by increasing the load from 8 Ohms to 4 Ohms (a smaller Ohms value equates to a higher load, as it indicates less resistance) the amplifier max output went from 200W to 600W. This illustrates how a load even just slightly higher than the specified range can work the amplifier much harder then intended.

Speakers can be wired in series, parallel, or mixtures of both to allow for many different combinations that will result in the desired load impedance. The more speakers that you want to incorporate into your system, the more complex you wiring configuration may become. Also, if a speaker were to become disconnected or shorted accidently, the amplifier may become overloaded and damaged.

A 70V speaker configuration simplifies this problem significantly. The 70V system works by using a transformer after the amplifier to step up the signal voltage. Another transformer is used at each speaker to step the voltage back down to conventional speaker levels. The higher voltage system is much less sensitive to small changes in impedance. The transformers at each speaker typically have multiple lugs that are labeled at the wattage they will draw from the amplifier. Any number and combination of speakers can be added to the circuit, so long as the total wattage draw from the amplifier does not exceed the stated max 70V wattage load. If a speaker is connected or disconnected, it will not throw of the impedance balance of the reset of the network, like can happen with conventional speaker voltages.

Another great advantage to the 70V speaker system is that it allows for longer wiring runs and the use of smaller gauge speaker wire. This is because the higher voltage from the step-up transformer also translates to less current and as a result less power loss over longer lengths of wire. This is similar to why the electric power utilities use step-up transformers and run the power long distances over high tension power lines and then uses step-down transformers at the power poles right before they enter a consumer's home.

One more advantage to a 70V system is in cases where you want to have separate volume controls at each speaker, in a multi-room setup for example. You can purchase 70V volume controls that are placed directly before a speaker's step-down transformer. These volumes controls are much more reliable and safer for your amplifier then their conventional speaker level counterparts.

So how do you decide which setup is best for you? The more speakers you want to use on a single amplifier channel, the stronger the argument for a 70V system. Other factors, such as very long runs of speaker wire also will support the case for a 70V system. Generally any single channel that needs 5 or more speakers, or has speaker runs over 75 feet may be better served with a 70V system. System's with only one or two speakers per channel, such as in a typical home theater setup, a 70V system offers few advantages and would add cost and complexity.

Posted by Mark at 21:02
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Vegistroke V3 Kit installation to F250 Powerstroke PSD 7.3L Diesel

This post has been moved to  http://www.modernsurvivalists.com/gear/vegistroke-v3-wvo-kit/.

Posted by Mark at 16:47
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Conversion of F250 Powerstroke 7.3L Diesel to Waste Vegetable Oil

This post has been moved to http://www.modernsurvivalists.com/skills/alternative-energy/converting-a-73l-diesel-engine-to-vegetable-oil/

Posted by Mark at 10:39
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EnergyStat - Our next generation thermostat

Prototype Enclosure Photo

The EnergyStat™ was initially created as our entry into Microsoft's Dare to Dream Different Challenge. The challange was sponsered by Microsoft's .NET Micro Famework team and was open to contestants internationally. The prizes ranged from hardware development kits to business consulting and startup cash to implement for the finalists. The competition has now concluded and our entry was selected as a semi-finalist (among the top 50)! We would like to congratulate all of the teams that submited an entry. We saw a lot of great ideas from the competitors.

Energy Efficient House Model

Our invention for the competition was a thermostat that offered a combination of thermal energy learning for the invironment it is installed in, as well as presenting info to the user that allows them to make more energy efiicient decissions when adjusting their climate control settings. The device is internet enabled so that it is aware of upcoming weather changes, diplay weather alerts, and can even allow the user to change their settings from anywhere they have internet access. The combination of all these features would untap additional energy savings out of the existing heating and cooling system in any home. The goal of the EnergyStat is to be the World's most energy efficient thermostat.

Hardware

Although the competition has ended we intend to continue developing this product to produce a version that is commercially viable. Please check this page for future updates on the EnergyStat™.

Hardware2

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Posted by Mark at 21:53
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