The first and most important step when considering an RF preamplifier is to determine if replacing the existing antenna with a new (higher performance) antenna would accomplish the same or similar results without the use of a preamplifier. If you are absolutely certain that you have properly installed the best antenna and related hardware for your site—and you continue to experience difficulty receiving OTA DTV broadcasts—then please read on. (Please keep in mind that without knowing where you live and how your antenna is installed it is impossible for someone other than yourself to determine if your current antenna is installed properly and is the best choice for your site.)
If you are roughly within what is referred to as a “Near Fringe” or farther reception sensitivity classification and you need (or want) to use a low-noise RF preamplifier then you will need to take every necessary precaution to minimize RF electromagnetic noise and interference from reaching your antenna preamplifier; preamplifiers will amplify not only the desired signal but also undesirable signals as well as noise. In addition, all RF preamplifiers contribute their own noise (some more than others,) which must be taken into consideration, especially when dealing with OTA digital television signals.
To help ensure the least amount of noise and interference you need to make every effort to mount your antenna as high as possible and away from surfaces that are capable of strongly reflecting RF signals in the digital television band (though in very rare circumstances nearby reflecting surfaces have been known to be beneficial with some signals.) Also, whenever you are using a directional antenna such as the WInegard HD-9032 it is very important that you aim it properly for each TV station’s signal that you want to receive. When using directional antennas if the TV transmitters in your area are widely spread across the horizon you will need to use an antenna rotator or multiple antennas if you wish to receive as many stations as possible.
One of the most important steps to help ensure that noise is minimized is to use the absolute highest quality, highest performance 75Ω coaxial cable and connectors for your antenna downlead. For this I highly recommend spending a little extra in order to use Belden’s nonpareil RG-6/U or RG-11/U Tri-Shield coaxial cable, part numbers 1694A and 7731A, respectively. A good source for the Belden RG-6 and RG-11 Tri-Shield coaxial cable is Blue Jeans Cable. (When installing coaxial cabling outdoors always be sure to use coaxial connectors rated for weather-tight outdoor use and always use plenty of waterproof, weather-resistant cable sealant and/or sealant tape. Note: do not use rubber silicone sealant. Also minimize tension on your antenna downlead and always adhere to the coaxial cable manufacturer’s bend-radius recommendations.)
The next important step is to ensure that you have a very good, low-resistance earth ground and that the shielding on your cabling as well as all equipment chassis are properly grounded. To reiterate what I said earlier, you want to minimize or, better yet, avoid amplifying the electromagnetic noise and interference that is present.
When it comes to high performance, mast-mounted low-noise VHF/UHF preamplifiers there are currently three standout choices (listed in descending order of both performance and price): the HDTV preamplifiers from Research Communications* (e.g. their Type 9261 preamplifier is the most appropriate model for UHF-only DTV broadcasts in the United States,) Antennas Direct Model CPA-19 and Channel Master models CM-7777 and CM-7778. *(Note: for U.S. residents the preamplifiers from Research Communications, though superior to virtually all other VHF/UHF preamplifiers, will cost approximately US$200 shipped - or roughly two-to-three times the cost of the units from Antennas Direct and Channel Master, respectively.)
Finally, before you commit to purchasing a UHF antenna preamplifier I strongly encourage you to carefully read through the informative OTA FAQ & Knowledge Base on the Digital Home Forum Website as well as the TV Signal Analysis FAQ on the excellent TV Fool Website, both of which I’ve provided links below.
######################## RESOURCES ########################
Digital Home Forum
– OTA FAQ & Knowledge Base
http://www.digitalhome.ca/forum/showthread.php?t=41102&pp=30
– Signal Amplifiers (Amps, Preamps, Distro Amps)
http://www.digitalhome.ca/forum/showthread.php?t=42426&pp=30
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Antennas Direct CPA-19 ClearStream Pre-Amplifier Kit
http://www.antennasdirect.com/antenna_amplifier.html
Antennas Direct Introduces CPA-19 Pre-amplifier
http://news.antennasdirect.com/prmanager/press-releases-detail.asp?id=100
Channel Master Amplifiers and Preamplifiers
http://www.channelmaster.com/productm.php?catmID=25
Research Communications, Ltd. - High Performance HDTV Preamplifiers
TYPE 9261 HDTV PREAMPLIFIER (470 - 700 MHz; Channels 14 through 51)
http://www.researchcomms.com/hdtv.html
################## ADDITIONAL RESOURCES ##################
TV Fool
– Mapping Tools: Google Earth Coverage Maps and Interactive TV Coverage Browser
http://www.tvfool.com
– TV Signal Analysis FAQ
http://www.tvfool.com/index.php?option=com_content&task=view&id=57&Itemid=89
RabbitEars
http://www.rabbitears.info
Better than AntennaWeb - How to use the site 2150.com
http://www.avsforum.com/avs-vb/showthread.php?p=7625830#post7625830
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Fix Reception Problems
http://www.dtv.gov/fixreception.html
As Analog Shutdown Nears, Antenna Reality Emerges
http://www.printthis.clickability.com/pt/cpt?action=cpt&urlID=29040747&url=http://broadcastengineering.com/RF/analog-shutdown-nears-antenna-reality-emerges-0609/index.html&showBibliography=Y
[PDF] New Research Sheds Light on Major Glitch in the DTV Transition
http://www.centris.com/ContentPages/9/Page361/12.08%20-%20DTV%20Glitch%20PR.pdf
TVTechnology
– Antennas for DTV Reception
http://www.tvtechnology.com/article/printableView.aspx?contentid=11584
– Solving VHF DTV Reception Problems
http://www.tvtechnology.com/article/printableView.aspx?contentid=79862
[PDF] Solving TV Reception Problems
http://rapidshare.com/files/201366511/TVRECEPE_-_Solving_TV_Reception_Problems.pdf
[PDF] Thin Air: ATSC Reception Isn’t Always Easy
http://www.edn.com/contents/images/6656302.pdf
Brian Dipert’s “Thin-Air ATSC (And NTSC)” Articles
http://www.google.com/search?hl=en&num=100&aq=f&lr=lang_en&as_occt=title&q=site:edn.com+%22Thin-Air+ATSC+(And+NTSC)%22
HDTVexpert
– Digital TV Reception
http://www.hdtvexpert.com/pages/receptionpf.htm
– DTV Reception Out On The Fringe
http://www.hdtvexpert.com/pages_b/ReceptionOnTheFringe.html
Ultra Satellite & Antenna Voodoo (USAV) - Off-Air FAQ
http://www.ultrasatellite.com/category-s/15.htm
DTV Antenna Resources (Periodically updated and revised as needed)
http://docs.google.com/View?id=dhpmqnbb_15f5t9j3gb
A/V Science (AVS) Forum
– HDTV Technical
http://www.avsforum.com/avs-vb/forumdisplay.php?f=25
– The Official AVS Antenna Topic!
http://www.avsforum.com/avs-vb/showthread.php?t=381623&pp=60
– Antennas, rotators, boosters/preamps... for wide-band VHF/UHF
http://www.avsforum.com/avs-vb/showthread.php?t=546066&pp=60
HDTV Primer
– Erecting a TV Antenna
http://www.hdtvprimer.com/ISSUES/erecting_antenna.html
– Antenna Basics
http://www.hdtvprimer.com/ANTENNAS/basics.html
– How Big Should the Antenna Be?
http://www.hdtvprimer.com/ANTENNAS/sizing.html
– Comparing Some Commercially Available Antennas
http://www.hdtvprimer.com/ANTENNAS/comparing.html
– It doesn’t work! Now what?
http://www.hdtvprimer.com/ANTENNAS/fixes.html
[PDF] Belden Coaxial Cable Catalog
http://www.belden.com/pdfs/03Belden_Master_Catalog/06Coaxial_Cables/06Coaxial_Cables.pdf
Analog/Digital RF TV Cables at Blue Jeans Cable
http://www.bluejeanscable.com/store/rf/index.htm
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Grounding Satellite Dish and Lead-In Cables
http://www.mikeholt.com/mojonewsarchive/GB-HTML/HTML/GroundingSatelliteDishandLead-InCables~20020303.htm
Article 810 – Radio and Television Equipment from Mike Holt’s textbook “Understanding the 2005 NEC, Volume 2”
http://www.mikeholt.com/newsletters.php?action=display&letterID=220