WINEGARD RELEASES VHF HIGH BAND/UHF VERSIONS OF THEIR HD PLATINUM LINE
It took a while, but perhaps they just wanted to get the right design out at the right time. Winegard Company in the Spring of 2008 released five new versions of their HD Platinum series antennas for long range off-air reception, and they are designed to receive channels 7-69. Most markets in the United States after the DTV transition will have their final frequencies in VHF High Band (7-13) and UHF (14-51), and these five antennas will receive these stations from a single direction.
If you are looking to replace your rooftop antenna, then I would simplify the search and focus on the HD7964P model, and then look at it in reference to the TV Fool Web site with its off-air signal predictor tool, which I discussed in an earlier blog. If your DTV channels can be received in a single direction (with a direction range of under 40 degrees) and all the noise figure numbers on the TV Fool predictor results are 5 or greater, then based on the gain numbers claimed for the HD7984 from Winegard, I would expect this antenna to get good reception provided only one DTV tuner is connected to the antenna with RG-6/U cable, with a direct run of 75 feet or less. If there are more tuners to be connected with this antenna and a splitter is used, or more cable is required, then a low-noise preamp may be needed if several of the noise figure results are between 5-15. This recommendation also is for an outside rooftop mount.
If all the predicted noise figures are above 15 for the DTV stations listed, then it may be possible the HD7964P will work in the attic. Based on the dimensions, this design should be easy to fit inside an attic space, allowing over-the-air reception while keeping the antenna hidden from view and not being an eyesore to some.
Winegard rates the HD7964P as a "zone 3" model for suburban locations. If it turns out the TV Fool model has several results at or just below zero, then you will want to consider one of their larger zone 4 models, which are larger antennas but have more gain and more range.
It took a while, but perhaps they just wanted to get the right design out at the right time. Winegard Company in the Spring of 2008 released five new versions of their HD Platinum series antennas for long range off-air reception, and they are designed to receive channels 7-69. Most markets in the United States after the DTV transition will have their final frequencies in VHF High Band (7-13) and UHF (14-51), and these five antennas will receive these stations from a single direction.
If you are looking to replace your rooftop antenna, then I would simplify the search and focus on the HD7964P model, and then look at it in reference to the TV Fool Web site with its off-air signal predictor tool, which I discussed in an earlier blog. If your DTV channels can be received in a single direction (with a direction range of under 40 degrees) and all the noise figure numbers on the TV Fool predictor results are 5 or greater, then based on the gain numbers claimed for the HD7984 from Winegard, I would expect this antenna to get good reception provided only one DTV tuner is connected to the antenna with RG-6/U cable, with a direct run of 75 feet or less. If there are more tuners to be connected with this antenna and a splitter is used, or more cable is required, then a low-noise preamp may be needed if several of the noise figure results are between 5-15. This recommendation also is for an outside rooftop mount.
If all the predicted noise figures are above 15 for the DTV stations listed, then it may be possible the HD7964P will work in the attic. Based on the dimensions, this design should be easy to fit inside an attic space, allowing over-the-air reception while keeping the antenna hidden from view and not being an eyesore to some.
Winegard rates the HD7964P as a "zone 3" model for suburban locations. If it turns out the TV Fool model has several results at or just below zero, then you will want to consider one of their larger zone 4 models, which are larger antennas but have more gain and more range.
posted by Derek (IA) | 8:23 PM
7 Comments:
I have had very disappointing results with the TERK HDTV antenna, the antenna that looks like a Yagi. It seems to have lower gain on UHF than a simple dipole. I thought perhaps I had one defective sample, but I tried another one in a strong signal area and again, found it had less gain than a simple UHF loop.
I am a electrical engineer.
Any clues?
Hello Stephen, here are a few recommendations for a typical Yagi antenna:
1) You say you are in a strong area, first of all, understand that the widest element is the BACK on the antenna, like the lens on a flashlight. The smaller elements point toward the transmitter signal source.
2) It may be possible that in a strong area, the dipole/loop which is bi-directional may be catching a reflected signal from BEHIND that your tuner might think is stronger. You might find you need to point the Terk in a different, maybe opposite direction, to "catch" that reflected signal, which is actually not unusual in some areas. Also. newer DTV tuners are more capable of locking on to stronger signals in cases where the antenna is receiving a line-of-site AND reflected signal.
3) Is your Terk antenna amplified? If so, the amplification might be overdriving the DTV tuner whereas a non-amplified dipole is doing the job. Also, some amplified antennas, if they are not powered, do not pass much signal passed by the antenna.
4) More tricks and a more technical explanation of DTV signal reception tricks were posted by me FOUR YEARS ago; August 2005, to be exact. Here is an instant link to that page: http://otahdtv.blogspot.com/2005/08/how-do-i-improve-digital-signal.html
Thanks for your reply, Derek.
Because of the odd performance of this antenna, I have been testing it without an amplifier and on low-power, UHF,analog transmissions. I have been doing this indoors, near a window. It appears to have no directionality at all. I will take it outdoors and see whether it behaves better.
Do you know how the driven elements of this antenna are coupled to the coaxial cable? It appears that there is a wire, enclosed in plastic, running under what would be the boom of a normal Yagi.
A few days ago, I had read your post http://otahdtv.blogspot.com/2005/08/how-do-i-improve-digital-signal.html and found it most informative.
Homeowner in NE Minneapolis; strong signal, mature trees
I went out to NE Minneapolis to investigate the case of a homeowner who had reported poor DTV reception. She lives on a wide street with a central boulevard and mature trees. Her house is on the west side. The location is 45.01102 N, -93.22715 W. Transmitters are at 45.05833N, -93.12417 W; about 6.2 statute miles away, line of sight.
At street level, I found that I could receive digital TV on all channels, but when I measured bit rate, I found larger fluctuations in bit rate than I had seen before, in areas without such large trees.
The Tivax converter I use has a bit rate indicator on a 0-100 scale. On channels such as 2.1, 2.2, and 4.1 the signal was fluctuating between 15 and 68 on this scale. The picture never "pixilated" but there were occasional, very brief, sound dropouts. There were no fluctuations on channels 9 and 11, which have moved back to the high VHF band. I attribute the fluctuations in the other channels to scatter of the UHF signal by the thick canopy of leaves. At this time, the antenna was about 5 feet above ground level, on the roof of the car.
The homeowner invited me in. I found that her first floor TV was a new, Insignia brand, digital TV. I found it connected to an RCA 1912 GM antenna, one designed to hang on the wall. To get a reliable signal, I connected the Insignia TV to the Radio Shack 15-1874 antenna. I then did a channel scan on the Insignia TV. To do a channel scan, one must first have a reliable signal, and the 15-1874 is my tried and true source of signal. I placed the antenna on a small table facing a window. The antenna was probably about 10 feet above ground level, and aimed toward Shoreview (toward the northeast). The channel scan found all the digital channels. We looked at the digital channels, and all had very good pictures and sound. The Insignia TV has an internal bit rate meter (a bar code display) and all signals were strong, with 4 or 5 bars. There was little fluctuation except for UHF channel 4, which was showing fluctuation between 4 and 5 bars. There was no pixelation and there were no dropouts, however.
I placed the RCA 1912 GM on the table and connected it. Its performance was generally satisfactory, but there were occasional sound dropouts on Channel 4.
What I learned:
In neighborhoods with mature trees, UHF scatter by leaves is significant.
There have been a number of changes in DTV channel assignment; hence a channel scan is important. But, one must have a good signal before one does a channel scan. Being uncertain about the signal and uncertain about the channels leads to frustration (as was apparent in the home owner's letter to MPR).
The simplest antennas, such as the Radio Shack 15-1874 (now $11.95) or the RCA ANT 111 ($9.95 at Best Buy) give better results than more elaborate antennas.
I was happy to try out the Apex converter in the field. This converter, sold with a coupon at Best Buy, and the Radio Shack Digital Stream converter are the most readily available to people who choose not to buy by mail order over the Internet. I was favorably impressed by the ease of use of the Apex. The Apex, the Digital Stream, and the Tivax are all satisfactory. In fact, they all use the same chip set
Homeowner in NE Minneapolis; strong signal, mature trees-Second Floor
This is the second floor of a homeowner about 6 statute miles, line of sight from Twin Cities MN transmitters.
On the second floor, the homeowner has a 13-inch analog color TV connected to an Apex converter. This was connected to an unamplified Terk HDTVa. I have been disappointed in the performance of this antenna. I placed the Radio Shack 15-1874 on a table in front of a window and connected it to the Apex converter. The antenna was now about 20 feet above ground level, aimed toward the northeast. I did a channel scan and the Apex found all the local DTV channels. We looked at the digital channels; all had good pictures and sound. The Apex has an internal bit rate meter, and signals were fluctuating, but staying in the 30 to 70 range, labeled "good" on the Apex meter. There was no pixelation and there were no dropouts.
Out of curiosity, I connected the unamplified Terk HDTV and found the signal weaker, with larger fluctuations and with sound dropouts. This is contrary to what one might expect, and I attributed it to the UHF signal being scattered by moving leaves and arriving at the antenna in a variety of directions. Since the antenna is directional, the scattered signal is only occasionally in the right direction, hence the weak signal and drop outs.
Fortunately, The homeowner had an old, "no-name" antenna with a UHF loop and VHF rabbit ears. I connected this antenna, and it performed about as well as the Radio Shack 15-1874.
So, I left the homeowner with two operating DTV sets.
What I learned:
In neighborhoods with mature trees, UHF scatter by leaves is significant.
There have been a number of changes in DTV channel assignment; hence a channel scan is important. But, one must have a good signal before one does a channel scan. Being uncertain about the signal and uncertain about the channels leads to frustration (as was apparent in the home owner's letter to MPR).
The simplest antennas, such as the Radio Shack 15-1874 (now $11.95) or the RCA ANT 111 ($9.95 at Best Buy) give better results than more elaborate antennas.
If by the TERK antenna you have been talking about the HDTVa all this time, I can tell you that this antenna as well as Phillips Silver Sensor use a small cable running inside the antenna mast to the coax connector. The purpose of this is to cancel, or phase out, the return current that causes backlobe radiation on a typical antenna drive element, like a dipole or loop, which makes the HDTVa and Silver Sensor directional in UHF without the need for passive elements that are needed in a traditional antenna design for directivity. While that may be a nice space saver, there is an issue I have with this method. Since the elements are not directly connected and balanced to the downlead, this introduces a mismatch in some frequencies that could result in inconsistent signal at the tuner.
Meanwhile, a simple dipole or loop directly connected to a balanced coax downlead would have a better signal match response across the UHF band, and that would be good reason why, in an area with strong signal and little multipath, especially with 4th and 5th generation DTV tuners, that the simple dipoles seem to fare better than the HDTVa/Silver Sensor model.
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