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A Street Tech Labs How-To:
One of the things your DirecTV, Primestar or DISH Network salesperson may have conveniently neglected to mention, when they were clinching the deal, is that you can't receive local TV stations on their cute little dishes. For the past five years, and until March 1st of this year, all systems were offering network programming (ABC, CBS, FOX, and NBC) through various affiliates. But the National Association of Broadcasters (NAB) brought suit against the providers of these satellite-delivered affiliates, which in turn brought the displeasure of the nearly two million affected customers upon the ears of their congressional representatives. Faced with the prospect of pending legislation which might have worked against them, NAB worked out a compromise which calls for all consumers receiving out-of-market network affiliates to be cut off by December of this year instead of April.
DISH Network is developing a long-term solution whereby network affiliates in the top twelve U.S. markets would be retransmitted over their service, but only to customers in those markets and blacked out everywhere else. This might appease NAB, but doubtless will earn the wrath of the powerful cable lobby which may take up the fight where NAB left off. At any rate, that scheme only helps those customers in the top twelve markets. The rest of us would still be without service, and as usual, the consumer is left to figure out what the hell to do.
A walk through any major retail electronics store reveals a bewildering array of set-top antennas and contraptions all of which promise better reception. A glance at the Radio Shack catalog shows the same thing. Here, we're treated to a parade of glorified rabbit ears with strange-looking coils, knobs and plastic, dish-shaped fixtures which seem designed to suggest satellite reception. These devices sport price tags anywhere from US$2 to $100. With most of these units, anything under $20 is of questionable value and anything over $20 is likely overpriced.
Time for a little education
For some reason, few people seem to understand the basics of radio and TV reception. This is why you see so many cars with coat hangers pronged where the antenna used to be. Folks think, "Hey, that thing was just a piece of wire. This coat hanger is a piece of wire. What the heck!" This is also how all manner of phoney reception schemes can find ready buyers at premium prices.
What you need to know is that the TV broadcast band runs from 54MHz (channel 2) to 216MHz (channel 13) in the VHF ("Very High Frequency") band. The UHF-TV (that's "Ultra High Frequency") band goes from 470MHz (channel 14) to 806 MHz (channel 69). I point this out because there are a couple of interesting things happening in the TV bands. One thing that's really neat is that the FM broadcast band (88-108MHz) lies right next to the frequency for channel 6. This is why you can tune in the audio of a channel 6 TV station on an FM radio (tune to just below 88 MHz). It's also why any VHF-TV antenna is also a good FM radio antenna. It's built-in!
Some of you old timers may remember when the UHF-TV band went all the way to
channel 83 and you may be asking, "Wait a minute, where'd the last 14 channels go?" Well, they were auctioned off to the highest bidder and are now the domain of the cellular phone industry. Yes, the frequencies from 806MHz to 890MHz are crammed with millions of Americans trying to drive their cars and chatter on their cell phones at the same time. Do not attempt to tune in those lost channels on an old manually tuned TV set in an effort to listen to those cell phone conversations because that would be illegal :-)
The object of the TV reception game is to capture as much signal as you can and deliver it to your TV set with as little signal loss as possible. To do this, you need two things: an antenna *designed specifically for the signals you wish to receive* and a feed line or antenna cable which carries the signal. This is why so-called "whole house antennas," which use the wiring in your house as a huge antenna, aren't very effective. The wiring in your house is not cut specifically for any signal you're seeking. In fact, it's a random length wire and prone to drag in more noise from electrical devices on the wiring than radio or TV signals.
RG-59/U 75 Ohm coaxial cable commonly used for video signals,
CB/Ham radio and TV antennas.
RG-6/U 75 Ohm coax cable used in internal antenna feed lines.
The feed line is trying to deliver the signal to the TV with as little signal loss as possible. To that end, the best feed line to use for TV frequencies is RG-6/U coaxial cable. Compared to RG-59/U coax, which is most often used in TV reception, RG-6 has 30% less line loss per hundred feet of run and doesn't cost much more. Gold plating on coax "F" connectors has no appreciable value as far as line loss is concerned.
If antennas are amplified, they are said to be "active;" unamplified antennas are "passive." If you live in a city, you're probably getting enough signal from the built-in antennas on your TV set for adequate reception. But the further away from the transmitted signal you get, the more your TV needs help in bringing in the signal. Despite their design implications, set-top rabbit ear antennas are typically no better than the telescoping antenna built into the set itself. These are passive antennas and the knobs on them are simply to change the electrical length of the rabbit ears to tune the antenna closer to the frequency you're trying to receive.
Amplified rabbit ear antennas have amplifiers built-in and need to be plugged into an AC power source. The amplifier is typically broad banded (capable of amplifying signals over a large range of frequencies), and again, there will likely be knobs on the top which adjust the electrical length of the antenna. Reception with an active set of rabbit ears will be better than a passive set, but don't expect miracles. Decent reception in distant suburbs or towns 30 miles or more from the station will take more than rabbit ears can deliver (sorry, Bugs).
One of the best ways to improve over-the-air reception is to bring the antenna directly into a VCR and use the tuner in your VCR to tune the TV bands. Tuners in most TV sets are notoriously lower quality and less sensitive than tuners in most VCRs. Stations which don't come in at all on your TV are likely to be at least viewable when tuned through the VCR.
The latest craze in TV reception are the flat, circular antennas in a plastic case which mount on a pole. They're amplified and are intended to tune VHF/UHF signals from all directions. Again, at $100, you're getting an attractive package with minimal capability suitable only as far out as the suburbs.
Here's a unique UHF/VHF antenna solution. The Freedom Antenna discreetly
attaches to the back of your 18" satellite dish. US$80 from Antennas America.
The best solution for off-air reception, in a suburban environment where outside antennas are restricted, is to mount a small outdoor VHF-UHF antenna (such as the Radio Shack VU-110) in the attic space of your home and run the cable (RG-6 coax) to the TV set. Orienting the antenna for best reception will give you access to all channels VHF and UHF (not to mention FM radio). Since the whole unit is completely out of the weather, it could last as long as your house, and for around $50, results will be far superior to set-top rabbit ears. In areas where restrictions are minimal, mounting an antenna outside and controlling it with a rotator (RS#15-1225, $65) will allow you to tune in signals from several distant cities in different directions. Investing in a much larger antenna will allow you to expand your horizons to over 100 miles. But, there's a limit. Single, amplified antennas 15 or 20 feet above the peak of your house will be unlikely to get usable signals beyond 100 miles. This is because TV signals and FM radio signals travel in line-of-sight, and while they will bend slightly, are not prone to reflecting in the atmosphere as are AM and Short Wave signals.
Put this baby in your attic for great reception
and an out-of-the-elements solution.
For more rural locations, simply add an antenna-mounted signal amplifier, such as RS#15-1108 for $40, which will dramatically increase your signal strength. Keep in mind that using an amplifier in an urban location may cause strong FM signals to create on-screen interference. For that reason, most such amplifiers have an "FM trap" switch which cuts off those frequencies from amplification. Turn this switch on and the interference should disappear.
Most small dish system receivers have an outside antenna input jack, which when
connected to an outside antenna, allows you to toggle between satellite and off-air service. If the receiver you use doesn't have such a feature, you'll need to combine the signals from the off-air antenna and the small dish into one and feed that into your satellite receiver. This device is called a diplexer and Radio Shack sells one (RS#16-2581) for $20.
For the adventurous who are strapped for space and would like to save some money, try "rolling your own" small space VHF-TV antenna. Radio Shack sells a dipole FM antenna (RS#42-2385, $3) which is intended for FM reception. Since the receiving element is 58" long it will make a good VHF-TV antenna which can be tacked up on the wall behind curtains or a dresser. The lead-in is 300 Ohm flat, 2-conductor, ribbon wire with terminal connectors at the end. If you attach the end to the screw terminals of their indoor TV/FM amplifier (RS#15-1104, $20), you'll have a very nice, easy to mount, nearly invisible, amplified indoor antenna for under $25. The antenna is directional and may be mounted vertically, or horizontally in one direction or the other. One way to experiment is to tack the antenna to a yard stick and rotate it around to see where the best reception is. Try putting it up as high as you can. This will also make a great FM antenna for your stereo.
Remember, you've got to use the right antenna to receive VHF and UHF TV signals. Spend a little more for better antenna cable, avoid overpriced "electronic breakthroughs" and don't expect miracles from marginal equipment. For a look at the wares of four off-air TV reception specialists check out the following:
- Ken Reitz [3/25/99]
[Editor's Note: As you have probably noticed from Ken's wonderful radio and satellite pieces on Street Tech, he loves his trips to "The Shack." We have to admit, we do too. For neighborhood convenience and a *fairly* decent selection, you can't beat a quick trip to Radio Shack. That said, there are still likely other great electronics stores in your area (often with much better selection and pricing than the Shack), and the people in such stores are often much more knowledgable than the teen sales 'droids at Radio Shack. There are also a number of really great mail order sources that we highly recommend here at Street Tech Labs. They are:
Most of these sites have limited items from their print siblings, sales items, and a place to sign up for a free mail order catalog. - Gareth]
Other satellite tech covered on Street Tech:
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