I'll assume the three different sized loops cover more of the UHF bands frequencies so to me that's some proof of engineering right there. That is the basic premise for all the double or 'tapered' looped antennas, right?
As for the argument that if it was any good they'd be making them today we know that's not necessarily true. Take for example the original Gray-Hooverman. A great antenna by all accounts but it's not manufactured in it's original dimensions anymore. The Radio Shack indoor 2-bay 15-623 antenna is another example of a great antenna no longer manufactured. More recently (while not an antenna) the CM7777 was reworked to be inferior to the original.
Tim58hsv "Double loop antennas are nothing new. I even found a pic of an old triple loop antenna"
Your picture is not a fair comparison, because it is nothing like the antenna I am trying to define here, although it is based on a similar concept. It is obvious I did not make my self clear. Look at the Clear stream C-2 antenna and tell me there is no engineering involved in it. I only drew the top half of this antenna to save time, and that is why there are also actual words on the drawing, which you either did not read, or did not understand.
There is supposed to be a second loop at the bottom (Which i mentioned in the drawing). Also, this is not separate pieces of wire as in your picture. This is a flat piece of sheet metal that makes up the driven element, not separate pieces. It is a tapered element that covers the old UHF 69 channel band, and could be modified for the current limit at channel 51.
It is obvious you really did not look at the drawing close enough, or read any of the detailed text on the drawing, or you would understand it a little better. Sometimes a picture IS NOT worth a thousand words, and some words need to be included also. It is obvious you did not read the words.
Updated drawing below. I hope this clarifies things a little better..The area highlighted in red IS NOT two separate pieces of wire as you assume. It is a flat continuous piece of sheet metal, preferably copper or brass or some type of non weathering metal.
This is a decent antenna, and it is available TODAY in the form of the Clear Stream C-2. It is replies like this one that are lacking in real facts that kept me away from here for so long, and it is not surprising that nothing has changed. At least I can do "ARTWORK" and don't have to search for someone else's picture to prove my point !!!
And I have a REAL TV BROADCAST ENGINEERING background to back up what I say. What are your qualifications and background? DO I have to post analyzer screen shots from a real professional antenna analysis device to show how this home made version really performs over you three wire version? Now I know why I avoided logging on here for so long. It didn't take to long for this to become the same old same old !! You were a real pain in the A_ _ back then, and I see nothing has changed.
I do more than "I'll assume", but it seems that is all you can do !!!! Wheres the LUV? Peace....
"And I had nothing to do with your leaving this board last year. That was your own choice...well that and another poster you were always at constant logger heads with."
It seems that almost every time i would post something back then, there was ALWAYS someone who thought they knew more than me. I don't claim to be the TV reception guru, but I do have more experience in this arena as a 10 year TV Broadcast Engineer, who was involved in the DTV transition from the very beginning, than most everyone who was "DISSING" my posts back then. I looked back at some of my old posts, and you are not completely innocent either, regardless of your denials.
My post on loop antennas is NOTHING even remotely like my revolutionary antenna design that I am trying to get a patent on. This is simply the basic design of the clear stream C-2, and has nothing to do with my own antenna design in any way WHATSOEVER !!
The C-2 has no capability to receive VHF signals in either of the VHF bands, where as mine is capable of receiving signals in both VHF bands. I am currently receiving channel 3 (Actual RF Channel, Not the virtual channel) at 20 miles from the transmitter with my antenna, using it INDOORS and it only measures 12 inches by 24 inches. It's main focus is on the UHF band, but it performs well on both VHF bands too.
I only posted the loop drawing to show roughly how the C-2 is designed since the thread topic was loop antenna engineering, and so experimenters can try different versions of it for themselves. I built one of these 3 years ago, and it only cost me the price of some small hardware, versus the $100 plus retail price of the C-2. My intent on this thread was to help do it yourself'ers to try this design and maybe improve on it and save a dollar on an antenna that performs well at UHF channels for mere pennies.
I was trying to share the Luv, but this quote "Double loop antennas are nothing new. I even found a pic of an old triple loop antenna", and "I think one would be hard pressed to find any good ideas for the use of a loop antenna since they pale in comparison to other UHF antennas such as yaqis and bowties", is simply not true.
The double loop antenna such as the C-2 with a back plane reflector added then becomes a very directional antenna, because as some may know, the C-2 is one of the best selling UHF antennas on the market right now, ( TV Technology - January 18, 2012 ) and my tests show it is very directional with the addition of the back plane reflector, and has high gain numbers with the addition of the second bottom loop. Even the single loop version (C-1) works fairly well as a city grade antenna, and is small enough to be used indoors.
I am not trying to stir controversy in any way, but I have built yagis, and multiple element bowties, and most any other type of practical UHF DTV antennas, and the double loop design is an innovative design with much engineering that went into its development, and it is an effective DIRECTIONAL ANTENNA. And yes, I do agree with your statement that omni antennas SUCK for DTV reception, especially in high multi-path areas such as where I live.
The irony here is that I have my own revolutionary antenna design, and I was only trying to be a participant an give this thread some new ideas, and I end up defending the loop design when my antenna is in no way similar to the loop antenna design in any way, and is far superior to it, and when my preliminary patent ( Patent Pending ) is granted, I will be glad to show it on here, and anywhere else I can promote it. I have two versions of it now, and am working on applying the concept to an indoor version also.
Poor Quality DTV Signal 1
Poor Quality DTV Signal 2
Good Quality DTV Signal
Proper Grounding Techniques
No matter what antenna experiments you try, be sure to observe proper grounding principals..ALWAYS !!!
Recently dusted off my TV after sitting for 10 yrs.
Have an old Maganvox 13" color crt unit.
Also have an Access HD DTA1010 digital converter.
Have constructed 3 DIY antennas & am currently using an omni directional that pulls in quite a few signals.
Have noticed that on my stations that are 50 miles & farther, the signal will come & go. Station might be on for an hour & then it will fade out, may come back on anywhere from 10 minutes to a few hours later.
Would a Preamp help keep the stations on longer?
My antenna is a bit over 30' in the air (9' above rooftop) with some trees nearby.
Clear view of North & West.
Terrain here is mostly flat. NW Ohio.
I have 4 local stations within 10 miles of home.
Would appreciate any ideas/thoughts to enhance my stations on time. :bowdown: TV Fool
Here is one I made. In the discussions below many of the possible problems are addressed. Basically though, these tpe of antennas are very forgiving in design. I have been making these for my boats, homes and even campsites for 30 years and you can pretty much guess at measurements and get it to work very good.
Anyone who is serious about studying and building loop TV antennas should study the loop antenna 4nec2 antenna simulation analyzes work that has been done by holl_ands. http://imageevent.com/holl_ands/loops;jsessionid=u023on22t1.goose_s
Living in an area where four major broadcast networks come from three High VHF transmitters at 230, 201, and 26 degree the simple circle, or square bi-dirctional vertically orientated VHF loops have worked quite well in many locations in this valley. While a full wave loop only has about 1 db gain over a dipole which would seem insignificant. In the real world my results have been a significant improvement in signal over a dipole. I've not yet played around with building a directional VHF loop with reflector. Examples can be seen here. https://sites.google.com/site/maycreates/ota-setup/diy-vhf-loop-antenna http://imageevent.com/holl_ands/loops/vhfloop http://imageevent.com/holl_ands/loops/looprefl
I also have a good assortment of low power UHF signals to work with in my area and have tried a few UHF loop designs which worked quite well for the UHF signals they were designed to receive, but had very poor VHF response. I have built the following trying my best to follow dimensions from the above site.
UHF "Figure-8" Twin Loops - NO Refl
UHF Twin-Hoop Chireix
UHF Hourglass Loop
I really do like the hourglass loop antenna I would like to work with that one a bit more. I've not yet built a VHF hourglass loop.
I've also built two Hi-VHF+UHF Bowtie-In-Loop antennas they worked better then I expected on UHF.
I do like loop antennas, but most so called omni designs are not really omni. http://imageevent.com/holl_ands/notfortv/hivhfuhfcircularpancakeloopfakeomni
In most areas there are better ways to accomplish ones reception goals then to try and build an antenna that receives equally poorly in all directions.
Loop antennas reject changes in capacitance. It's why you can get close to a loop UHF antenna and not change the reception. But loop antennas are sensitive to inductance. If a large metal object is moving in the vicinity your fancy loop could detune especially if it's a big hunk of iron like a garbage truck going down your street or 747 overhead.
Of course as it goes by your picture will blink and waver.
On the other side of the coin a straight element di-pole (rabbit ears) is sensitive to capacitance and not inductance.
If you get close to a di-pole it can de-tune and again your picture will suffer. This really gets bad if your neighbor is herding zebras with volunteer digeridoo players.
But a garbage truck going by will have little effect.
Of course the idea is to combine both of these to get a rock solid picture.
For HDTV a 6 inch diameter loop and two 12 inch long straight elements work great.