Just got done throwing this thing together just to see what DTV stations I could pull in. Works wonders and was easy to build. Made out of coat hangers, sanded down part where interconnects. Black taped ends so no poking eyes out.
Each wing is 7" long 3" spread apart. It's a pretty basic configuration. Middle wires are connected to a balun to convert down to 75ohm coax.
Plugged into my TV I got about 12 stations. I could probably pull in a lot more if I went outside with it and mounted it high up in the air.
Even though I have cable TV it's always nice to have a backup and this thing works better than the store bought ones do
It works better because those dumb store units are single stage elements shaped like some fancy oval sound snooper dish.
What you got there is a multi-bay unit with 4 stages of the proper way to get gain for a reception antenna in the UHF bands. All you need is a couple of old BBQ grates angled at 90* and connected at the inner center, connect it to ground of the antenna and wala you have a very high gain and very directional UHF multi-bay bow-tie array.
Yes....it will work incredibly well!!
Peace!
K-ROCKS RadioOne
ZeroPointRadio
AM Stereo 1670
FM Stereo 92.1
Lol I was calling it a batwing antenna, but I guess bowtie is the proper term for these antennas?
Also will putting a reflector grate on this increase the gain at all or just make it directional? I feel like I should know the answer to this but I'm not sure.
Also just found this antenna design... www.digitalhome.ca/ota/superantenna/index.htm Any idea if this would be an improvement over the bowtie antenna? This field of UHF antennas is completely new to me.
Ive always heard and referred them as being "bow-tie"...but bat wing has also been used by some. The confusion comes in when the elements are solid instead of a rigid wire, whereas the solid elements appear more like a bow tie and the rigid wire type forming a horizontal V, called bat wing.
How about this one....a friend of mine who is an FCC field engineer calls the folded dipoles "paper clip antenna"! I replied..."Imagine a day's programming in text form on a huge piece of paper attached to the paper clips and the pain changing out the day's program log...don't need a transmitter. just a very tall and secure ladder!"
The second antenna design is basically the same thing with the exception of each bay connected together on the outer edge of the elements instead of cross connected at the center. Same concept with just a bit of a twist approach. Should perform quite well like the other.
The reflector will make the antenna highly directional and thus give added gain in that direction. If the reflector is positioned just right, it could also help increase gain efficiency, just like how a satellite dish or microwave dish adds considerable gain to a feed horn spaced a certain distance at the center of the dish. Works the same principles as a "sound scooper" dish used at football games on the side lines. They point that dish at the field and pick up sounds from the players or point it across the field to try to hear what the other team and coach are conversing about. Sort of a "Sportsman Sound Snooper". This is why we hear all the grunts and groans when the players knock each other over during a play.
UHF is fun to play with...and indeed a whole new world compared to VHF and lower. Extremely line of sight and requires far more power to send a signal over a distance compared to the lower frequencies. This is why most UHF and microwave installations use high gain directional arrays or dishes.
Peace!
K-ROCKS RadioOne
ZeroPointRadio
AM Stereo 1670
FM Stereo 92.1
Thanks for the reply RFBurns. After getting some sleep and getting my brain working on coffee instead of beer I remembered that reflector panels do add gain.
Of course there is the option of directors also, but from reports I have read of people trying to add directors to a bowtie antenna it doesn't do much at all until you have like 4 or 5 director elements in front of the bowtie elements so it just sounds like a waste of time.
I think I will just build another 4 bay setup identical to this one and then combine them and add a chicken wire reflector behind them. Either way as is I am impressed with how well this drags in signals.
I have seen some designs call for 7" wings and others for longer. Most of the DTV stations here are on the higher bands so I think the 7.5" elements (15" bent into a V) work just fine. If anyone has some idea as to how to combine and add a VHF-hi element to this that would be wonderful.
I also wonder about the balun. I have a few and some of them I wonder if they are fake or just crap. The one I used seems to work best, but the others don't even make conductivity between any of the 300 and 75 ohm connectors. Made in China my first guess is that they are just fake or contain capacitors going from the 75 to the 300ohm connector. I plan on ripping one apart just to see if it's fake or how the hell they made them. I know the average balun for TV sets make conductivity usually through all parts via coils which used to be a way to tell if the U ends were open or not from yanking.
I find this an exciting new stupid hobby side project for myself. I want to see just how many DTV signals I can pull in. Strange how the oddest projects can make me so intrigued and intimidated
LOL! I always got a kick out of those advertisements and the wording used to peddle those useless things. Oh they look nice...fancy.....wow a satellite dish looking apparatus sitting on top of the tv instead of hanging on the wall or mounted on a pole. Oh look....Legal in all 50 states too!! WOW....no cable box necessary!!! No installation or wiring required!!! Just totally WOW!!
And its compatible with all sizes of tv's!!! Complies with all applicable federal regulations too!!!
Yep...all the right sales pitch mumbo jumbo to those completely unaware about this stuff...perfect bait for perfect sucker customers.
Then after a few thousand buy these silly things and give them a try and find out the aluminum foil worked better...its no wonder they gave them away at 5 bucks a drop.
I think these would go nicely in a display cabinet with a big sign above "Most ridiculous and useless"
RFB
K-ROCKS RadioOne
ZeroPointRadio
AM Stereo 1670
FM Stereo 92.1
In a way though it makes me sad how little people understand about antennas, or radio/TV broadcast for that matter. Now that it's a damn near lost art people don't even care anymore. They just call a number, have some dude come out and then plug in a cable to their set. Those who do play with DTV are lost in an information gap. Pick out the goofy looking thing at walmart that we know is useless beyond 3 or 4 stations, or pay for cable service which gives them 3 or 4 stations worth watching. I guess there was a time when people cared enough to pick up good stations, and stations cared enough to put out good programming. Now we are stuck with cable TV and though we pay it still has advertisements, though most channels are free OTA and people are sleeping too much to understand that half the channels are free in the first place, they completely forget about Free To Air FTA satellite. It's sad really. Oh well we always have the internet. Though one time broadcast TV mattered. To some of us it's still fun, but to the majority they rather pay for stuff that is free, not pay attention to society suckering them, buy the goofy fake satellite looking bunny ear antenna. It's been happening for decades. Yet I build a stupid antenna out of coat hangers in the proper way, and people look and point.. what is that?? We are a dieing breed. Though I hope knowledge lives forever. I'm only 26 y/o, but I still remember watching local TV news on a B&W TV in my room that I got from a garage sale for 1$ Those were the times.
A lost art is an understatement. In fact...us radio/electronic/electrical/experimenters/inventors are almost put into the same category of being crazy or insane.
My next door neighbor just cannot figure out why I have all these strange looking things on masts with cables running to them when they point out that the cable company only uses one cable.
I politely replied..."All these frequencies are yours except Uranus....do not attempt any connection there.....Use them together....use them in peace"!
Their reply..."What is Uranus?"
I replied..."Behind you".
They proceed to look behind them as if something or someone was approaching them from behind.
I just shook my head and went back into the house.
Its up to the rest of us to keep these arts alive..even if we are surrounded by "huh?"
Peace!
K-ROCKS RadioOne
ZeroPointRadio
AM Stereo 1670
FM Stereo 92.1
Well I will admit one thing about people who don't have a clue, you'd be surprised how few of them have any idea what the FCC is, it's purpose or function. So that's always a positive thing for us who bend the rules broadcasting entertaining radio shows
Indeed! I read a research report and heard this report on an alternative news program that 25 percent of the US population have no idea that this country was founded and established through a revolution against the British monarchy, and that those who fought to create this country did in fact perform acts of terrorism against the British, both abroad and right here on our own turf.
And even more do not truly know why we celebrate Independence Day or the meaning behind it.
Radio..well that is so far back on the back-back burner in most minds. The only time it becomes a concern and moved up to the front of the line is when it wont turn on or display something.
That's why most troubleshooting tips in manuals always start out with.."Is the unit plugged in?" or "Is the power switch flipped to the ON position?"
Peace!
K-ROCKS RadioOne
ZeroPointRadio
AM Stereo 1670
FM Stereo 92.1
Update: I added a reflector screen behind it. Tested both with and without and there is a 10% signal difference, so the reflector definitely increases the gain! Tried a few different balun transformers and found that some seem to be better than others. I decided to put the balun right through the wood and glue it in place, this way the coax plugs in behind the reflector rather than drooping it in front past the open wires. This also seems to improve gain not having the coax as far away from the active parts as possible. Spray painted my creation aluminum colored to look a bit more pro.
Front:
Back: (note where the coax plugs in)
Over all I am very impressed by this antenna. Cost me a whole 3$ for the paint, the rest was junk laying around the house. Best of all I can pull in all the stations around here, even a few as far away as 80 miles, and that's w/o using a tower.
Quick question, should I ground the reflector to the coax or not? Does it even make any difference?
Update: I added a reflector screen behind it. Tested both with and without and there is a 10% signal difference, so the reflector definitely increases the gain!
Quick question, should I ground the reflector to the coax or not? Does it even make any difference?
I would not worry about grounding the reflector if this will be a near ground mounted unit or mounted on an isolated mast.
If it is grounded, you might have to adjust its distance a bit from the bow tie elements, probably up to 2 inches or so.
That set top pos in the ad could never perform as well as your homemade unit can...and yours wont need any amplifier, which those silly antenna booster amps just add more noise floor to the overall system. Oh yes the booster amps will increase the signal catch of the antenna...but also increase the noise floor along with it!
And at its current state, you still beat the price of that pos set top unit, and have a far better performing antenna than that fake antenna could ever dream of reaching!
Note to wives out there: Lately there has been an unusual number of reported oven and refrigerator racks turning up missing mysteriously. Rest assured, the Department of Homeland Security, working in conjunction with local authorities have declared this "oven rack terrorism" as top priority as we approach the 9/11 10th anniversary. Their advice is to just relax and enjoy the anniversary presentations on the many OTA Digital HDTV stations you can pick up now. Much more to see on tv...move along!
Peace!
K-ROCKS RadioOne
ZeroPointRadio
AM Stereo 1670
FM Stereo 92.1
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