DIY Build your own HDTV Antenna

Posted on July 29, 2008. Filed under: Entertainment, Home & Garden, Uncategorized | Tags: , , , , , , |

Please Note:  on July 6, 2009  I posted an updated version of this article which includes the 4 key things every good antenna must have on called The Post DTV Transition Explained Part 2:  How to Build Your Own DIY HDTV Antenna and Save Money

For additional background and information, read the blog posts:

The Post Digital TV Transition Explained Part 1: What’s in it For You? What You Need to Know Now covers why the Digital TV transition happened, how you can benefit, understanding the UHF/VHF channel reassignments, why you might be experiencing reception issues and which DTV option is best for you?

and also How to Recycle An Old Satellite Receiver Set Top Box instead of Buying a Digital Converter Box

Stay tuned and subscribe to the Part 3 of The Post Digital TV Transition Explained, is a work-in-progess that will provide details on how to build an easy, yet very unique,  compact VHF/UHF antenna (i.e.,  low SWR over a very wide band width, high gain, directivity and scalable).  The design is ‘out of the box’ thinking and is very different.

This is the original blog post from last July, 2008:

TV stations are now broadcasting both the analog (VHF) signals and the digital (UHF) signals. In February, 2009 analog will go away. Some of the stations will return to the old channel assignment which will be in the higher VHF range. will give you all the info for the stations, channels and signal ranges in your area. There are also some definitions and good explanations about antenna basics for beginners at HDTVPrimer

My very first post was about switching from cable television to free Digital TV and how I did it. In that post, I mention that I am currently using rabbit ears perched on top of my tv set. I also mention that my father, a true geek in the best sense of the word, has committed to building me a better antenna which I have yet to receive. I think he is contemplating design and packaging for shipping from Massachusetts to California, most likely with some assembly required on my part. He also works full-time as a sales executive in the IT industry, so his free time for his hobbies is limited.

Here is a photograph of one of the antennas my father made that he is currently using at home with a flat panel HDTV. He designed it for the UHF HDTV station spread in the Boston market (e.g. 500 to 650 MHz). He says it works like a champ and receives all the stations in the Boston area at signal levels of between 9 and 10. His house is at sea level, the antenna is indoors on the second floor, and the stations are 24 to 28 air miles away.

The antenna is 18″ long and has 7 elements, the longest being 15″ and it works as well (perhaps slightly better) than a db4 or the double quad he also made. My Dad made this antenna (elements and boom) from 1/2″ x 1/16″ aluminum stock that he bought at a Lowes home center for about $8. Construction is pretty straightforward. He used nylon screws and nuts to isolate and attach the 2 booms together. The elements were fastened to the boom with 4-40 screws and nuts. The piece that looks like a tail at the end of the antenna is called a coupler, which is an impedance transformer to convert from 300 ohms to 75 ohms.

The antenna shown above is based on a rather sophisticated LPDA (Log Periodic Dipole Array) antenna designed by the US government. The selection of design parameters to arrive at the antenna’s exact physical design specs needs to be customized to the task. It requires advanced mathematical calculations that my father used an online JAVA calculator to perform. Unless you’re an engineer or math whiz, it may not be for the novice antenna builder.

By making it longer with more elements, my Dad says it will beat the pants off of anything you can make or buy. It can also be scaled to cover from VHF through UHF. He feels it’s his best effort to date, although he is constantly looking for ways to improve it or “build a better mousetrap.” To that end, my father has been scouring his local area for a discarded or unused Dish TV satellite dish to design an antenna around. This includes checking out the free “swap shed” at his town dump.

If you’re interested in learning how to build your own HD TV antenna and other DIY techie projects, a great resource is the forum on the LumenLab website. There are much simpler yet very functional designs, posted about in the HDTV antenna thread. For example, the double or quad array bow tie antenna (also known as DB2 or DB4) which can retail for $50+. Many of these design implementations could easily be built by the average person and use common everyday items and tools you probably have lying around the house or garage, such as glue guns, wire coat hangers, cardboard, scrap wood, metal screws, washers, and aluminum foil. There is a good video on how to build an HDTV antenna out of wire coat hangers on YouTube worth watching.

Here is an example of a DB4 posted by Squeeto on the LumenLabs forum made from copper wire, synthetic building wood and cheap cooling racks.

You can find my father’s posts there under the member name Serndipity (spelled as such). Also look for posts by Pitman2, along with various designs, modifications, and lots of good advice.

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