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Author Topic: Over the air HDTV antennas - recommendations? Bobby Henderson "Ask me about Trajan." Posts: 10973 From: Lawton, OK, USA Registered: Apr 2001 posted 02-04-2008 11:14 PM                     What brand/model of antenna do you use to pick up over the air HDTV broadcasts? I need to get a better outdoor antenna for picking up more HDTV channels. The old one I'm currently using is able to pick up all the analog channels in the Lawton-Wichita Falls TV market. It also picks up the digital channels Lawton's ABC affiliate is now broadcasting (at first you needed to be connected via the local cable TV company's digital cable service). I need a new antenna sensitive enough to pick up Wichita Falls' digital channels. And if the antenna is good enough it may even pick up channels in Oklahoma City. But it seems to be tricky getting the right antenna. I have a Dish network account, but the local channels carried on it are not available in HD. And our local ABC channel is just squeezing and cropping its 720p digital channel, down-sampling it and giving that to the satellite companies to re-broadcast. Kinda sucks.  |  IP: Logged Joe Redifer You need a beating today Posts: 12859 From: Denver, Colorado Registered: May 99 posted 02-04-2008 11:33 PM                        I have a Terk something-or-other, but it is amplified and that actually seems to help. The problem is that nobody is broadcasting digital at full power yet until they build a new tower in the mountains. Hopefully sometime this year I'll get better reception. Whenever the wind blows or the trees grow leaves, my reception gets jumpy and I miss the punchline to one of Jay Leno's AWESOME jokes.  |  IP: Logged Paul Mayer Oh get out of it Melvin, before it pulls you under! Posts: 3836 From: Albuquerque, NM Registered: Feb 2000 posted 02-05-2008 04:13 AM                        For your application Bobby, I think any good high-gain antenna will work. High-gain antennas, as typically used in fringe reception areas, are also quite directional. A narrow beam pattern is desirable with digital signals since such patterns will help reject off-axis signals and cut down on multipath interference. Multipath with analog signals just means seeing "ghost" images. Multipath with digital signals can cause the baseband part of a receiver to have difficulty locking to the incoming bit stream - resulting in signal dropouts even though the RF signal strength and the RF part of the receiver is working just fine. The over-the-air part of ATSC in this country was designed primarily for outdoor antenna use. Indoor "rabbit ear" style antennas may work, but the system was designed and optimized with outdoor antennas in mind. The situation was made a bit worse when the FCC decided to go with 8VSB (8 Vestigial Side Band) as the US OTA modulation standard. Most of the rest of the world went with COFDM (Coded Orthogonal Frequency Division Modulation), which is much more robust in multipath-prone areas, such as cities and urban areas. 8VSB works best in areas where there are not a lot of structures or other objects that cause the signal reflections that lead to multipath interference. Since its adoption as the US OTA standard, there have been improvements to 8VSB which have improved its multipath performance. One drawback to highly-directional antennas may be the need for multiple arrays or a rotator. From Lawton, the angle between Wichita Falls and OKC is about 110 degrees is it not? You may need one of those solutions to obtain the best signal quality from both directions. Interesting back story (or not) - In the late '90s the engineers at Sinclair Broadcasting saw this potential problem area and tried to get the FCC to approve both modulation schemes for OTA use. Some manufacturers even began making dual-scheme ATSC receivers and STBs, but then the FCC went with 8VSB only. The conspiracy theorists say this was a deliberate decision designed to hobble OTA ATSC in the hopes of getting everyone to switch to cable. Then the spectrum currently designated for OTA ATSC can be auctioned off - more money for the feds. No more free OTA signals. You want access to that programing? Pay for it then. Take that story with as big a grain (or rock) of salt as you need.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 02-05-2008 09:56 AM                     Actually NOT ANY old antenna will work all that well. HDTV is transmitted on the UHF band which presents its own specific set of problems as Paul mentions, especially with multipath. Most of the combo antennas I've worked with seem to put most of the engineering dollar into the vhf section and not into the uhf. Unless you are really still wanting to spend $$ on the soon to be obsolete VHF spectrum then purchasing a strictly UHF antenna is in your favor, especially if you have any fringe stations you're wanting to pick up. At 110 degrees spacing apart a rotor is more or less mandatory. Since you want about 1000uv's down at the television antenna terminals you have to select an antenna with the correct amount of gain to get you there... more than 1000uv at the terminals and you stand to overload the front end of the ATSC tuner. In your area the Weingard HD-9095P is a good bet. I am using the HD-9075 here at home and get a two thirds signal level on all the stations that transmit from Farnsworth Peak. We are lucky to have all the DTV signals comming from more or less one place on the mountain here in SLC as there is no multipath problem what so ever. Mark  |  IP: Logged Bobby Henderson "Ask me about Trajan." Posts: 10973 From: Lawton, OK, USA Registered: Apr 2001 posted 02-05-2008 10:05 AM                     I suspect our local network stations are not broadcasting in HD at full power either. The local Fox affiliate, KJTL has a couple different towers, one of which is in Oklahoma about 30 miles from here. But according to antennaweb.org, I would need a more powerful "violent zone" rated antenna to receive the signal, which suggests KJTL is not putting much power behind their DTV signal. Other affiliates may still be broadcasting over the air in analog. You need a "blue zone" rated antenna to get decent reception of their analog signals. Obviously it seems like the broadcasters may be trying to save money on electrical bills by not broadcasting their DTV signals at greater signal strengths. The Lawton-Wichita Falls market covers a pretty big area of territory, so whenever the complete switch to digital broadcasting happens those stations may even need to install more transponder towers to cover bigger chunks of rural areas. One thing I wondering, which channel will each broadcast station give up when analog broadcasts are ended in 2009? Channel 7 here in Lawton is, obviously, channel 7. Will they just start sending out a more powerful digital signal in that space? Or will they be stuck with their other frequency and possibly a different channel number? I was looking at a couple of outdoor antenna models from Terrestrial Digital. Their products are featured on the antennasdirect.com web site. Their DB8 model looks like it might do the trick for capturing signals from Wichita Falls. OTOH, I worry about how that kind of antenna will hold up in Oklahoma weather. High wind and hail from severe storms probably wouldn't be very nice to such equipment. It's tempting to contact management at the local affiliates to see what their plans are regarding over the air digital broadcast over the next year. Again, I'm wondering if they will install more signal transponders. Lawton and Wichita Falls are in the same broadcast market, but are an hour's drive apart.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 02-05-2008 10:13 AM                     You may be right about the low power... many DTV Stations are still running temporary 1000 watt transmitters(PBS in Reno is one), some of them were installed in just a few days time. That is all "supposed" to be temporary though. When the VHF units are switched off permanently these stations will more than likely see construction permits come through for much higher power permanent installations. The Denver area is(was?) another DTV problem area with only temporary transmitters operating because the "Tree Huggers" were preventing construction of a new tower on one of the mountains. Also, there are some markets that simply cannot afford to operate both transmitters, Casper, and Cheyenne Wyoming are two of those that will be strictly VHF to the very end. Contacting the involved stations is a good idea... ask to speak to the "Chief Engineer" or at least the "assistant chief" if they have one... the average tech in the studio is unlikely to know what the actual transmitter plans are. BTW: The channel 7 thing... from what I've head the VHF spectrum will be sold off mainly for beefing up emergency channels. There are more new fangled antenna companys sprouting up claiming all sorts of needs for receiving DTV but for the most part its pure bull shit....kinda like Bose. 10db gain is only so-so performance from the Terrestial. Nothing works better then a high end Weingard or Channel Master antenna... I've put up literally hundreds of them over the years. Some of my installs in the Chicago Burbs could swing the antenna around and pick up Indianopolis!! Your home owners insurance should cover any damage to your antenna that might happen... Have also done alot of "inisurance" type of work in that regard!! Mark  |  IP: Logged Bobby Henderson "Ask me about Trajan." Posts: 10973 From: Lawton, OK, USA Registered: Apr 2001 posted 02-05-2008 11:46 AM                     That's good to know about the antennas. Judging from some of the online reviews the Weingard model you mentioned appears to be a good choice. It may turn out to do the job much better once the local broadcast affiliates have pushed all their transmitting power exclusively to their digital channel(s). It's funny you mention the "tree huggers" in Colorado. The last few times I visited Colorado Springs I noticed cell phone towers being painted forest green and having little metal fake tree branch looking things attached. The end result is more obnoxiously cheesy looking than any cell phone tower I've ever seen. The Black Forest area north of the 'Springs has a few of them. Quite laughable.  |  IP: Logged David Stambaugh Film God Posts: 4021 From: Eugene, Oregon Registered: Jan 2002 posted 02-05-2008 12:09 PM                        OTA TV reception here in Eugene is very problematic. First, the transmitters are evenly divided between two different locations, like 100 degrees separated. Then there are hills and valleys etc. to contend with. I live in one of the valleys, still within city limits and only 10 miles from the most distant transmitter(s), yet OTA reception is horrible, even on VHF. UHF is even worse. In a situation like that, with transmitters in different locations, can 2 directional UHF antennas be combined to cover both sources? Or is a rotator the only option? BTW, I have a Zenith Silver-something indoor UHF antenna. I am not impressed. I also have an RCA amplified indoor UHF antenna, wasn't very expensive, but it seems to work fairly well if you set it up carefully. I've tried an amplifier on the Zenith and it does help but it's still very fussy and can't bring in a steady digital signal from FOX.  |  IP: Logged Mitchell Dvoskin Phenomenal Film Handler Posts: 1869 From: West Milford, NJ, USA Registered: Jan 2001 posted 02-05-2008 12:39 PM                     Over the years, I have not had much luck with amplified antennas. Most amplify more noise than signal. I am about 40 miles northwest of Manhattan, and I get all the New York HD stations perfectly with my 20 year old Radio Shack roof antenna.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 02-05-2008 12:45 PM                     David, I think in your case the optimum reception is only going to happen by rotor and medium gain directional UHF antenna. Downtown Chicago has similar problems to yours but is mainly due to buildings reflecting the signals. You certainly don't need any high gain stuff like Bobby may need f you're just 10 miles from the towers. A rotor is the only way to point directly to the actual tower(s) when they are that far spaced... otherwise you'll be watching the multipath and not the signal. Omnidirectional antennas are also not going to help at all... you need to pinpoint the signal to elminate the ghosting(multipath). Mark  |  IP: Logged Bruce Hansen Jedi Master Film Handler Posts: 847 From: Stone Mountain, GA, USA Registered: Dec 1999 posted 02-06-2008 09:58 PM                     There will still be some DTV broadcasts on VHF after Feb. 16, 2009. For example here in Atlanta, NBC's DTV is 10 (NTSC is 11), one of the PBS DTVs is 12 (NTSC is 8). There are no plans that I know of to sell of VHF TV freqs, but UHF TV CH 52-69 will be sold off some time after 2-16-09. Check the FCC web site to find what channels will be in use in your area. (here is one place I found a list, but I don't knwo if it is the latest version: http://hraunfoss.fcc.gov/edocs_public/attachmatch/DA-06-1082A2.pdf BTW, if you want to apply for your (up to) two $40 off coupons for the downconverters to use with your old TVs and DVD recorders that don't have DTV tuners, go to www.dtv2009.gov . The coupons will be sent out when the converters come to market. At this time, they think this will happen in late Feb. or early March.  |  IP: Logged Joe Redifer You need a beating today Posts: 12859 From: Denver, Colorado Registered: May 99 posted 02-06-2008 10:16 PM                        quote: Bobby Henderson Channel 7 here in Lawton is, obviously, channel 7. Will they just start sending out a more powerful digital signal in that space? Or will they be stuck with their other frequency and possibly a different channel number? They can remap the digital channel to 7.1 So you'd "tune" into 7.1 on your HDTV, but the HDTV knows that it is really channel 53 or some such craziness. That's why you have to scan for digital channels before you can actually tune them in. quote: Mitchell Dvoskin Over the years, I have not had much luck with amplified antennas. Most amplify more noise than signal. Well that isn't really much of a problem with DTV since it isn't analog. You simply can't get noise in the picture. Artifacts, yes, but that just comes from the super crappy MPEG 2 technology which was invented before Columbus came to America. MPEG 2 is for fools. With my TV, it has a diagnostics menu which shows the signal strength of an ATSC channel. Turning the amplification down generally lowers the number from 70 to 42.  |  IP: Logged Bobby Henderson "Ask me about Trajan." Posts: 10973 From: Lawton, OK, USA Registered: Apr 2001 posted 02-06-2008 10:24 PM                     Actually, KSWO's DTV channel here does register in my TV as channel "7.1." And I think that sort of sucks because I can just see some doofus seeing "KSWO DT 7.1" on the channel label and think they're broadcasting in 7.1 surround sound.  |  IP: Logged Ron Funderburg Jedi Master Film Handler Posts: 814 From: Chickasha, Oklahoma, USA Registered: Nov 2007 posted 02-06-2008 10:54 PM                        The ABC affiliate out of OKC doesn't broadcast strong enough to get it where I live just south east of Chickasha. The reason given is that they step on the Lawton signal if they broadcast strong enough to get here, but we don't get the Lawton stations here so how can that be right?  |  IP: Logged Bobby Henderson "Ask me about Trajan." Posts: 10973 From: Lawton, OK, USA Registered: Apr 2001 posted 02-07-2008 12:23 AM                     Are you not picking up KSWO's DTV signal or are you not picking up KSWO at all, digital or analog? If you're not even getting KSWO's analog signal that would seem strange since it can be picked up in Wichita Falls, which is farther from Lawton than Chickasha. About 15 or so miles farther. I think the stations around here are just being cheap with their electrical power usage. They probably figure too few people in this area are using HDTV to make the effort of broadcasting powerful DTV signals worth it. They also likely figure the few that do have HDTV are getting local channels through digital cable or something. Guess we'll be waiting until sometime next year before DTV signals in SW OK will be strong enough to get over the air at significant distance.  |  IP: Logged

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