Anyone here ever make and/or try out a homebrew HDTV Antenna?

[Frank-0-Video]

Greetings ...

Although I myself have not attempted to make or use a "homebrew" HDTV antenna, I am wondering if anyone here has either made or acquired one themselves. If yes, what materials was it constructed with, and what reception results did you get?

Thanx-A-Lot, Frank-0-Video

[MysticE]

http://www.google.com/search?q=homebrew%22+HDTV+antenna%2C&ie=utf-8&oe=utf-8&aq=t&rls=...ient=firefox-a

[dphirschler]

I was going to make one but after I saw all the mathematical calculations I'd need, I decided against it. So I just used my rooftop UHF/VHF TV antenna. Worked just fine. In fact I used a cheap $20 Radio Shack UHF antenna which I mounted poorly (under my deck), aimed poorly (it was aiming into a hillside and only in the general direction of Atlanta), and it still picked up excellent reception.


Darryl

[Mark F]

I made one similar to this, based on the Channel Master 4221:
http://uhfhdtvantenna.blogspot.com/
It was pretty easy to make, but didn't bother with the foil reflector.

The reception isn't bad. It's better than an indoor model I tried, but not as good as the CM4228 I have in the attic.

[C_Copeland]

I have a tin roof on my home. How will that affect reception with an attic-located antenna, if at all?

[rumplestiltskin]

I have a tin roof on my home. How will that affect reception with an attic-located antenna, if at all?

I'll hazard a guess that your roof will act as a Faraday Cage. http://en.wikipedia.org/wiki/Faraday_cage

[trhouse]

I built the one described in the link provided by Mark F. over the Xmas holiday for a relative. We compared it against a simple UHF loop antenna and the Philips MANT940 powered antenna which is about $40 at Walmart.

The tests showed the homebrew antenna could not quite perform as well as the Philips but was much better than a simple loop. The homebrew antenna was more directional than the Philips. They decided to go with the Philips because no rotator was needed and the Philips showed better signal strength on all the channels we compared.

Construction note: The homebrew antenna did not initially work well at all. I removed all the bowties but one and found that worked well enough. I next added another bowtie and altered the distance between them until it showed a gain in signal strength. Using that distance, I then added back the next two bowties using the spacing that showed a gain in signal strength and it worked.

[SLK001]

Just remember that the bow-tie antenna is a UHF antenna and if this is the only antenna you have, your VHF channels will suffer (channels 7-12 are still going to be used). At least the very low frequency channels are no longer going to have high power TV on them (54MHz to 88MHz), so you will no longer need the 8ft+ elements.

Also, the use of "High Definition Antenna" is just a marketing ploy to get unsuspecting people to go out an buy a" "HD capable" antenna. Any VHF and UHF antenna that receives the frequency being transmitted will work. I have an older VHF antenna in the attic (my antenna "farm") that has a front-back ratio of 0dB, so that I can receive channels from the north and the south on the same antenna (I happen to live directly north of Miami channel's transmitter farm and directly south of Palm Beach channel's farm). I can pick up stations 60 miles away (or could, since most stations have gone to lower power while they have people on the towers removing the older antennas - once completed this year, they will resume high power TX'ing). For UHF reception, I use two Radio Shack high-gain corner reflector UHF antennas (with aluminum mesh between them to increase their F/B ratio).

I also have a small, emergency ASTC TV that works quite well on all DT channels with just cheap rabbit ears.

[C_Copeland]

I have a tin roof on my home. How will that affect reception with an attic-located antenna, if at all?

I'll hazard a guess that your roof will act as a Faraday Cage. http://en.wikipedia.org/wiki/Faraday_cage

I was afraid of something like that. Thanks for the reply. 8)

[Frank-0-Video]

Greetings ....

Well, this doesn't qualify as 100% homebrew, but some homebrew effort went into it.

I went into my storage unit and found my classic Radio Shack UHF Bowtie Antenna. Once back in my apartment, I attached a 300-to-75 ohm transformer where the current 300-ohm leads are. Next, I measured and cut out a section of cardboard, then put aluminum foil on one side. Next, the "foil-board" was taped to the back of the antenna, foil-side facing front.

I then attached one end of the short 75-ohm cable that comes with the Channel Master CM-7000 Converter Box to the antenna, the other end going to ANTENNA IN on the Converter. That cable was meant for the CM-7000's RF OUT to TV, but I am using the composite/S-Video outputs instead, and they run into my DVD recorder's inputs.

Finally, I carefully propped my creation in the window facing outward, the bow ties partially going thru the blinds. For extra support, a couple of storage boxes were pushed up against the back of the antenna.

What did I get for all my efforts? Well, here's the results ...

»» WRBL CBS-3 (15) (1-1080i, 2-480i) Signal 100%
»» WTVM ABC-9 (47) (1-720p, 2-480i) Signal 100%
»» WJSP GA PBS-28 (23) (1-1080i, 2/3-480i) Signal 100%
»» WLTZ NBC-38 (35) (1-1080i) Signal 100%
»» WGIQ AL PBS-43 (44) (1-1080i, 2/3/4-480i) Signal 50% to 75%
»» WXTX Fox-54 (49) (1-720p, 2-480i) Signal 100%

There's another local station, WLGA CW-66 (31), but I am unable to pick-up its signal, transmitted at 100-KW from 30-or-so miles away.

Thanx-A-Lot, Frank-0-Video

[SLK001]

There's another local station, WLGA CW-66 (31), but I am unable to pick-up its signal, transmitted at 100-KW from 30-or-so miles away.

Quite a lot of stations right now are transmitting at reduced power. They are doing this while they are installing their permanent digital frequency antenna (a lot of frequency shuffling occurred, thus requiring a new antenna) and removing their old analog frequency antenna.

A 100kW channel only 30 miles away should be about blowing your socks off.

[gshelley61]

There's no such thing as an "HDTV" antenna

That's just marketing BS

Regular UHF and VHF television antennas (like what everyone used to use before satellite and cable) are all that are needed. Most of the digital stations are on UHF frequencies, with some on VHF frequencies in certain markets.

www.tvfool.com

www.antennaweb.org

These are the two best websites for finding out specifically what frequencies the digital stations are carried on in your region, their signal strengths, direction and distances from your location - that will help determine what type of antenna(s) you will need to effectively receive them.

[edDV]

The main difference between the old VHF/UHF antennas and newer "DTV" (not HD) antennas is the reduced bandwidth these antennas need to cover (Post Transition). Antennas can be designed with more gain in smaller sizes. Upper VHF antennas can be much smaller.

Old VHF: Ch 2-13 (54-216MHz)

New VHF: Ch 7-13 (174-216MHz)

Old UHF: Ch 14-83 (470-890MHz)

New UHF: Ch 14-51 (470-698MHz)

Example of an upper VHF only antenna.

http://www.solidsignal.com/prod_display.asp?PROD=Y5-7-13&xzoom=Large#xview

[ahhaa]

I have a tin roof on my home. How will that affect reception with an attic-located antenna, if at all?

There is a possibility that if you mounted your antenna outside but above the roof, the roof would act as a reflector- actually boosting your signal. 8) Or perhaps you could even use the roof itself as an antenna...

Did you ever hear of the Slinky antennas?
http://www.nonstopsystems.com/radio/frank_radio_antenna.htm
http://www.eham.net/forums/Towertalk/3423

[rumplestiltskin]

I have a tin roof on my home. How will that affect reception with an attic-located antenna, if at all?

There is a possibility that if you mounted your antenna outside but above the roof, the roof would act as a reflector- actually boosting your signal. 8) Or perhaps you could even use the roof itself as an antenna...

Oh, would that be cool or what?

[gadgetguy]

If the roof is grounded (either deliberately or inadvertently) it won't work as an antenna. There is no National Code that I'm aware of requiring the roof to be grounded, but there may be local codes requiring it. If it is grounded, it will more than likely act as a shield and make an antenna in the attic virtually useless.

[ahhaa]

An accidentally grounded metal roof might do what Franklin did with his kite, attract lightning; and in the process could turn the rest of the house into an excellent Leyden jar. oops

[gadgetguy]

Urban myth. A grounded roof will not "attract" lighting. Lightning will only hit the roof if it happens to be the highest point in the area. Which is true whether it's grounded or not.