Chicago Tribune Article
I set up my father-in-law's box Sunday. He bought the Magnavox at Wal-Mart without a coupon. He said he just wasn't all that worried about $40, but methinks he was more worried about falling for a scam.
Anyway, I hooked it up to the simple little UHF antenna up on the roof, one of those $15 jobs, connected to 300 Ohm leads that terminates to a combination UHF/VHF spliter and 75 Ohm converter. The antenna is aimed at Fort Wayne at a location north of Convoy. He gets WANE, WPTA, WISE, WFWA, but nothing from WFFT. Their analog signal on channel 55 has always been weaker, so maybe there's an obstruction in the way of the digital, or their digital is still running at low power.
The El Cheapo antenna must have a pretty good back lobe, as he gets WTLW. But not WLIO. That may be due to the UHF/VHF spliter. I have a simple "all pass" 75 Ohm converter I can hook up, and we'll see if WLIO makes the grade. He gets WLIO via WATCH TV, so there's no loss here.
I put in an A/B switch that lets him switch from converter box to WATCH TV. Since both boxes are sending an RF signal on channel 3, he gets a little RF bleed-through, but not bad enough to worry about. This is on his 13" kitchen TV, after all.
Steve
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( 3.1 / 235 )On Monday, September 1, 2008, 14:40, Greg Oen wrote:
Hi Fred. I recently upgraded my brother-in-law's antenna for DTV. Since they have 4 TV outlets they wanted all the channels they could get without using a rotor. They're located a couple of miles west of Philothea wich puts Dayton and Ft Wayne nearly back-to-back with each other.
The signals are roughly the same between the 2 cities. Lima signals are no problem. Since we wanted to avoid a rotor I decided to try a 4-bay UHF with the reflector screen removed. I figured I still had 4 stacked dipoles! This would cover Dayton and Ft Wayne. For Lima, the Winegard HD7695 looked like a logical choice since it covers the high VHF as well as the UHF band and had decent gain.
I mounted the 4-bay as high as I could get it on the mast pipe on the top of their 40 ft tower and aligned it NW and SE for Dayton and FT Wayne. About 3 ft below it I mounted the Winegard and pointed it NE for Lima and Bowling Green. They already had a Channel Master 0264DBS preamp (separate UHF and VHF 300 ohm inputs).
I used it on the 4-bay. For the Winegard I used a 0064DSB preamp. It has 1-75 ohm all channel input and matched the HD7695. Of course I ran a separate length of RG-6 for it. With the tower work (hopefully) done, I decided to sample signal levels. Not surprizingly, all the Lima signals, including WLIO, were blowing us away. Dayton and Ft Wayne weren't doing too bad eithor, with signals in the 50 to 80 range (on a scale of 0-100).
My last challenge was to combine the 2 antennas. I couldn't afford to lose very much from the 4-bay and I had more than enough from the Winegard. I decided to use a 7dB drop tap as a signal combiner. I ran the 4-bay in one of the thru ports and connected the other thru port to the distribution system. The Winegard went to the -7dB port. IT WORKED! The signals from the Winegard were strong enough to survive a 7dB loss and the Dayton and FT Wayne signals are strong enough as well.
We are using a distribution amplifier to make up for the splitter and line loss through the system. Just for curiosity we looked at the analog signals and were surprised to see very little in the way of ghosting and co-channel interference on most channels, with the exception of Dayton channel 16 and 22; South Bend IN is running those same 2 channels in analog. Anyway, on the digital side it looks like we got by with breaking a few rules, and all appears to be well. Sorry I got a little long, but I thought you'd be interested.
Greg Oen
Minster OH
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( 3 / 210 )FCC ANNOUNCES EXTENSIVE NATIONWIDE INITIATIVE FOR DTV OUTREACH
Agency to Focus on Markets with High Levels of Over-the-Air Television Viewers
FCC News Media, Clyde Ensslin, 202-418-0506, clyde.ensslin((at))fcc.gov
Washington, DC – FCC Chairman Kevin Martin today announced a nationwide initiative to increase awareness about the upcoming transition to digital television. The FCC identified target television markets for specific DTV outreach, including all those markets in which more than 100,000 households or at least 15% of the households rely solely on over-the-air signals for television.
Chairman Martin announced that the five FCC Commissioners and other Commission staff will fan out to these and other markets to raise awareness and educate consumers in the days leading up to the digital television transition on February 17, 2009.
At each stop, there will be a public event, such as a town hall meeting, workshop, or roundtable with an FCC Commissioner to highlight the digital transition, and be available to local press. In coordination with these visits, the FCC will work with local broadcasters and radio stations to increase the broadcasts of Radio and TV DTV PSAs. All combined, this outreach is designed to educate consumers in these DMAs and especially those groups that are most vulnerable in the transition: Seniors, People Living Tribal and Rural Areas, People with Disabilities, Individuals with Low-Incomes, Minorities and Non-English Speakers.
Chairman Martin was joined by representatives from the National Association of Broadcasters, Consumer Electronics Retailer Coalition, Consumer Electronics Association, and the National Cable Telecommunications Association for the announcement at the Newseum in Washington, DC, one of the television markets identified. The NAB and members of the DTV Coalition will be assisting the Commission throughout this nationwide tour.
“As part of our efforts to prepare consumers for the transition, we have identified television markets in which the largest number of viewers will have to take action to be prepared for the transition six months from now,” Martin said. “This unprecedented nationwide tour by the entire Commission is part of our commitment to prepare and educate consumers about the digital television transition.”
Recognizing the challenges many viewers in these communities may face, Commissioners unanimously agreed to travel coast-to-coast to hold public events, meet with community leaders, broadcasters, and other stakeholders to highlight steps consumers need to take to be prepared for the transition.
In the coming weeks, an FCC Commissioner will be in the following cities:
Anchorage, Alaska 8/27/2008
Fairbanks, Alaska 8/28/2008
Baltimore, Maryland 9/8/2008
San Francisco, California 9/11/2008
Austin, Texas 9/18/2008
Houston, Texas 9/17/2008
Memphis, Tennessee 9/19/2008
New York, New York 9/27/2008
Boise, Idaho 9/29/2008
Atlanta, Georgia 9/29/2008
Missoula, Montana 9/30/2008
Helena, Montana 10/1/2008
Bozeman, Montana 10/2/2008
Billings, Montana 10/3/2008
Nashville, Tennessee 10/7/2008
Charlotte, North Carolina 10/16/2008
Denver, Colorado 10/16/2008
Seattle, Washington 10/20/2008
Spokane, Washington 10/21/2008
Yakima, Washington 10/22/2008
Portland, Oregon 10/23/2008
Chicago, Illinois 11/20/2008
Phoenix, Arizona 12/29/2008
The Commission will release periodic updates on markets that the Commission will visit as future trips are finalized.
In the days prior to each visit, FCC staffers will be on the ground providing technical and outreach assistance to local broadcasters, community leaders, and other stakeholders, to prepare for the transition to digital. The FCC will also be coordinating with NAB to explore whether these DMAs may participate in a temporary turn off of their analog signals (“soft tests”) to determine consumer readiness of the DTV transition.
The following is a list of areas the FCC will visit prior to February 17, 2009. More information will follow regarding upcoming dates for the remaining cities.
Albuquerque-Santa Fe, New Mexico
Anchorage, Alaska
Atlanta, Georgia
Austin, Texas
Baltimore, Maryland
Bangor, Maine
Billings, Montana
Boise, Idaho
Boston, Massachusetts
Bozeman, Montana
Charleston, South Carolina
Charleston, West Virginia
Charlotte, North Carolina
Chattanooga, Tennessee
Chicago, Illinois
Chico-Redding, California
Cincinnati, Ohio
Cleveland-Akron (Canton), Ohio
Colorado Springs,-Pueblo, Colorado
Columbus, Ohio
Dallas-Fort Worth, Texas
Dayton, Ohio
Denver, Colorado
Des Moines-Ames, Iowa
Detroit, Michigan
Duluth-Superior, Minnesota
El Paso, Texas (Las Cruces, NM)
Erie, Pennsylvania
Fairbanks, Alaska
Fort Wayne, Indiana
Fresno-Visalia, California
Grand Rapids-Kalamazoo-Battle Creek, Michigan
Green Bay-Appleton, Wisconsin
Greenville-Spartanburg, South Carolina
Harlingen-Weslaco-Brownsville-McAllen, Texas
Helena, Montana
Honolulu, Hawaii
Houston, Texas
Idaho Falls-Pocatello, Idaho
Indianapolis, Indiana
Joplin, Missouri-Pittsburg, Kansas
Kansas City, Missouri
Knoxville, Tennessee
La Crosse-Eau Claire, Wisconsin
Lansing, Michigan
Laredo, Texas
Los Angeles, California
Lubbock, Texas
Madison, Wisconsin
Memphis, Tennessee
Miami-Fort Lauderdale, Florida
Milwaukee, Wisconsin
Minneapolis-St. Paul, Minnesota
Missoula, Montana
Nashville, Tennessee
New York, New York
Philadelphia, Pennsylvania
Phoenix, Arizona
Portland, Oregon
Raleigh-Durham, North Carolina
Richmond-Petersburg, Virginia
Rochester, New York
Sacramento-Stockton-Modesto, California
Saint Louis, Missouri
Salt Lake City, Utah
San Antonio, Texas
San Diego, California
San Francisco-Oakland-San Jose, California
Seattle-Tacoma, Washington
South Bend-Elkhart, Indiana
Spokane, Washington
Springfield, Missouri
Tampa-St. Petersburg, Florida
Toledo, Ohio
Tucson, Arizona
Tulsa, Oklahoma
Twin Falls, Idaho
Washington, DC
Wausau-Rhinelander, Wisconsin
Yakima-Pasco-Richland-Kennewick, Washington
Yuma, Arizona-El Centro, California
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( 2 / 363 )FCC LAUNCHES DTV SPEAKERS BUREAU.
News Release. News Media Contact: Rosemary Kimball at (202) 418-0511, email: Rosemary Kimball CGB
http://hraunfoss.fcc.gov/edocs_public/a ... 4632A1.pdf
FCC ANNOUNCES EXTENSIVE NATIONWIDE INITIATIVE FOR DTV OUTREACH.
Agency to Focus on Markets with High Levels of Over-the-Air Television Viewers. News Release. News Media Contact: Clyde Ensslin at (202) 418-0506, email: Clyde Ensslin MB
http://hraunfoss.fcc.gov/edocs_public/a ... 4629A1.pdf
WILMINGTON BROADCASTERS WILL PROVIDE EMERGENCY ANNOUNCEMENTS AND INFORMATIONAL MESSAGES ABOU THE DTV TRANSITION AFTER SEPTEMBER 8 ON TRADITIONAL ANALOG CHANNELS.
News Release. News Media Contact: Clyde Ensslin at (202) 418-0506, email: Clyde Ensslin MB
http://hraunfoss.fcc.gov/edocs_public/a ... 4633A1.pdf
Note: Wilmington NC will be the FIRST community in the USA to become 100% digital. What happens in Wilmington will be a good indication of what will happen in west central Ohio in February 2009.
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( 3 / 205 )It's been a while since I posted information, but a real good link for evaluating Converter Boxes is ...
WIKI Converter List
My standard disclaimer is that you always have to watch and weigh what WIKI publishes, but this seems to be the best information so far on converters.
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( 3 / 206 )This link was passed on to me by our IT administrator. This is GOOD info for the home viewer.
Sanyo TV FAQ - PDF download.
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( 2.9 / 220 )From CGC Communicator ...
In the event of a major disaster, most portable battery operated TVs will become useless as of February 2009; people might actually have to listen to radio, imagine that.
LINK TO STORY
Fred replies ...
I've seen some new digital televisions that use a 12-volt wall wart to power them. With the correct connector, a television could run for several days off a battery.
However, at my house, I have a Sharp digital TV plugged into an old computer backup. When we lost power back on June 9th, it lasted for about 12 hours.
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( 3 / 224 )A viewer sent me this Article on TV Antennas, and said it provided a lot of good information. I have to agree.
Although this is old information, (from the 50s?), it is well worth reading. Ignore the highly technical stuff if you are not into radio and television, or engineering. But the overall scope of the article in the aiming, positioning, and cabling of antennas is very good.
Fred
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( 3 / 295 )It's funny how the more we advance, the more things stay the same. Take for example a viewer trying to get distant stations. Such was the case with one of our viewers in Putnam County who not only wanted to see WLIO's signal, but also the Toledo stations and Fort Wayne.
I had suggested that he look at one single antenna, on a small tower on his farm. However, he did some research and found an article about stacking two or more antennas together for added gain. The result? Read below....
Dear Fred,
I took your suggestion for the antenna on a 30 foot tower. It worked well, and I could get your station, as well as all the other stations in Lima. I also received Bowling Green and some of the Fort Wayne stations in both regular and digital.
Since we had a little down time on the farm, I did some fishing on the Internet and found an article about stacking antennas. I got curious if it would help and I purchased another antenna. After installing it, all I can say is WOW! I could get all the Lima stations, Fort Wayne, and Toledo. I even had channel 9 from Canada on with some snow, but that is 100 miles away.
I'm sending you the article. Thanks again for your help! This antenna works great.
Ted
Here is the article that Ted sent to me. The amazing thing? Look at the date of the article. Some things don't change, do they?
From The June 1975 Issue Of ELECTRONIC TECHNICIAN/DEALER
Stacking TV Antennas
By James E. Kluge
The author is a technical editor in the Engineering & Research Division of the Winegard Company.
The improved directivity achieved by stacking antennas can significantly reduce or eliminate many types of television interference.
Multiple TV-antenna arrays, reminiscent of the ‘50s, are making a reappearance around the country. Today, however, the principal reason for stacking antennas is not only to achieve increased gain out in the fringe areas, but also to solve interference problems through the use of highly directional antenna arrays.
Many urban areas today are plagued with multiple high-rise buildings and heavy users of electrical power, both of which cause television interference (TVI) problems. Typical TVI problems include ghosts, electrical noise and interfering radio signals which usually arrive from a direction slightly off axis from that in which the antenna is pointed. Ground reflections, ignition noise and reflections off moving ground or airborne reflectors, such as trucks and large aircraft, arrive from above or below and cause picture breakup.
Proper stacking of today’s highly sophisticated TV antennas can significantly improve directivity and selectivity, as well as gain.
OPERATION OF A SINGLE YAGI
The Yagi antenna, the most commonly used type for TV, "sees" electromagnetic radio waves in a manner similar to the way we see. Our eyes see in the general direction in which our head is pointed. Similarly, the Yagi antenna "sees" in the general direction in which its boom is pointed. When viewed from above (Fig. 1), the Yagi antenna’s outline more or less resembles an arrowhead because it tapers out from front to rear. The taper is more pronounced in broad-band antennas than in single-channel antennas. The arrowhead formed by the antenna should, generally speaking, point in the direction from which the desired signal is arriving; i.e., toward the TV transmitter.
Ideally, a TV receiving antenna should "look" in a straight-line path toward the transmitting antenna and "see" nothing above, below or to either side. Not being ideal, of course, even the best TV antennas "see" a considerable amount of undesirable signals arriving from an angle off the axis of the antenna, just as our eyes have some side vision. These signals can cause ghosts and other interference patterns on the TV screen.
A Yagi antenna is made up of many parallel elements arranged along a common axis in a horizontal plane and all oriented toward the signal source. The length, spacing and phasing of each element relative to that of the others determines how the.voltages induced in individual elements reinforce (add) at the antenna terminals. The elements are arranged and spaced so that the signal wavefront arrives at each element sequentially and so that the voltage induced in each antenna element combines at the antenna terminals with voltages from the other elements, to yield an optimized voltage which produces maximum gain over the desired bandwidth.
If the signal arrives from a source above or below the horizontal plane of the antenna, it will arrive at all of the Yagi elements simultaneously instead of sequentially. Under these conditions, the combined voltage at the antenna terminals will be something less than the optimum for which the antenna was designed.
VERTICAL STACKING
Stacking two identical antennas on a common vertical mast significantly narrows the vertical beam-width angle. That is, vertically stacked antennas more effectively reject those interfering signals arriving from above or below their horizontal plane than does a single antenna. It’s as though they were looking through a horizontal venetian blind. Because there’s nothing mounted to the side of either antenna, their side-to-side vision is virtually uneffected. In the process, gain increases about 2.5 dB over that of a single antenna.
Vertical stacking improves both gain and vertical directivity. This helps reduce airplane flutter and attendant picture roll, and certain types of ground noise and ground reflections.
The basic principle of stacked antennas involves the difference in the time of arrival, and therefore the phase, of signals intercepted by the antenna combination. If a pair of identical Yagi antennas are mounted one above the other, a wavelength apart, on a common vertical mast and are oriented identically (pointed) toward the signal source, any TV signals traveling horizontally and arriving from any direction will be intercepted simultaneously by both antennas.
Those signals arriving on axis from the direction in which the antenna is pointed will be strongest.
Because the antennas are identical, the generated signal voltages arriving at the output terminals shared by the antennas will be in phase, causing them to add directly. Theoretically, there should be a 3 dB increase (double) in signal power over that of a single antenna, but, because of losses in the coupler and cable, the actual gain increase will be somewhat less than 3 dB.
An important point to remember is that, regardless of the azimuth angle between the antenna orientation and the signal source, the arriving signal will strike any given identical points on the two antennas simultaneously. However, if the signal is arriving from a source above or below the horizontal plane of the antenna, the previous statement is no longer true. For example, if the wavefront is from a source below the plane of the antenna, the signal will arrive first at the lower antenna and the signal voltage from the top antenna will lag the signal from the lower antenna. The signal voltages at the antenna output terminals will no longer be in phase, and partial cancellation will take place. The opposite is true if the signal arrives from above (Fig.2C).
The angle of arrival and the resultant difference in arrival time causes a phase difference which reduces the magnitude of the combined voltages. You should begin to see now why two vertically stacked, identical antennas have a more restricted "vision" to signals arriving from a point above or below the horizontal plane than does a single antenna.
HORIZONTAL STACKING
Stacking two identical antennas side by side in a horizontal plane significantly narrows the horizontal beam-width angle, as shown in Fig. 4. That is, the antenna combination, like a horse wearing blinders, "sees" fewer interfering signals arriving from the sides while its vision up and down (in a vertical plane) is virtually unaffected. In the process, gain increases approximately 1.2 dB over that of a single antenna.
If two identical antennas are arranged side by side in a horizontal / plane and the signal wavefront arrives directly from the front, each antenna "sees" the same wave or field at the same time. If the wavefront arrives from a source above or below, the same is still true, except that the individual antennas are not operating as efficiently. However, if the wavefront arrives from one side or the other , the antenna on the side from which the signal is arriving will "feel" the signal first, causing the voltages induced in each antenna to be out of phase. This, in turn, causes partial cancellation of the antenna voltages when they are combined.
The up and down (vertical) "vision" of a horizontal stack is comparable to that of a single antenna, but its side-to-side "vision" is more restricted.
QUAD_STACKS
Stacking four identical antennas, two vertically and two horizontally in a rectangular or diamond pattern, restricts the vision of this combination in all directions off the axis. Called a quad stack, it "sees" as though it were looking through a tube pointed in the direction of the transmitting antenna. Gain is increased approximately 4 to 5 dB over that of a single antenna.
GENERAL TECHNIQUES
Before you start putting up an array, you should be aware of the following basic considerations which apply to dual and quad stacking of antennas:
1. Stack only identical antennas.
2. Maintain approximately one wavelength spacing (at lowest channel frequency) between antennas.
3. Cut phasing lines or connecting cables to equal lengths.
4. Length and phase of twin-lead interconnecting harnesses is critical.
5. Horizontal supports should be nonmetallic.
6. Avoid running interconnecting cables horizontally.
Vertical stacking is easier than horizontal stacking simply because in vertical stacks the antennas mount on a common vertical mast and spacing is easily adjusted.
However, with the excellent gain and high directivity of most Yagis today, vertical stacking is seldom necessary. If additional gain is needed, two vertically stacked identical antennas spaced more than ‘/2 wavelength apart will increase signal power by 3dB compared to that of one antenna. However, part of the increased gain will be lost in the connecting cables and the coupler.
Horizontally stacked antennas also must be spaced so that their booms are separated by a distance equal to more than ‘/2 wavelength of the lowest channel frequency. This spacing is needed to prevent the tips of the longest reflector elements from touching. Also, the horizontal supports must be nonmetallic; redwood or cedar 2’ x 4’ s are commonly used.
The severe ghosts caused by high-rise buildings, water towers and mountains can be reduced or eliminated by horizontally stacking two Yagis. However, the wavelength of a channel 2 signal exceeds 17 feet, making such an array for channel 2 unwieldy, heavy and subject to damage from ice and/or high wind. Fortunately, ghosting is more of a problem at high-band channels, and high-band antenna dimensions are significantly smaller. For these reasons, usually only high-band Yagis are stacked horizontally.
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( 3 / 287 )Another good source for information on REAL LIFE reception of DTV signals is the Worldwide TV FM DX Club.
This group of people have real hands-on experience in the equipment and the reception techniques.
I have reviewed their web site and found it to be 100% accurate.
BTW, they also have reviews on converter boxes!
Web site: www.wtfda.org
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