New Improved Antenna Design working Great so far.

Gary350 · 02-08-2010, 06:00 PM

I am redesigning my 16 element collinear array antenna again. Here is what I have learned from reading the Amateur Radio Antenna book.

Book says a dipole antenna is 75 ohms and it has a gain if 2.15 db per element. 4 dipoles in parallel have a gain of 8 db.

Book says several dipoles can be connected in parallel as a single element. If a dipole is made up of 3 different length elements each designed to pick up a different frequency a single element can be used to pick up all 3 frequencies.

Book shows pics of 16 element dipole elements in a 16 element array. Book says bowtie elements have a slightly better gain than a straight element.

Book says a long antenna can be coiled to make the physical size shorter the antenna still acts like a long wire antenna.

Book says reflector screen should be .2 wavelength from the elements. I did not build it like that but it is possible to do it that way. The elements would each have to be in different locations starting with the highest frequency element closest to the screen. So far so good.

I have dipole elements on each of my 4 antennas arrays. So far I have changed 4 of the 16 elements to, 608 MHz, 482 MHz, 186 MHz, 554 MHz. So far so good channel 8, 17 and 28 are FINALLY coming in at 90% strength again. I made a change the a few days ago these 3 channels dropped to 25 to 55% mostly unwatchable.

So far it seems to be working.

I am still receiving channel 7 in Knoxville about 120 miles away which I think it totally amazing. The signal must be a reflected signal off of a house because the back side of my antenna is facing Knoxville.

I am still experementing. I plan to change this again after I learn a few things. I need the antenna to pick up all 8 frequencies so I need a design so each element contains 8 different length dipole elements each being spaced .2 wavelength from the screen. I am going to build a metal frame just as soon as I learn what I need to know and get all the channels coming in good. The antenna is bolted to the side of the house now with a 2x4 lumber support system. I picked up 30 feet of 2" diameter pipe for a 30 foot tower. It will need some wires to hold it ridgid. I think it will be a problem to stand this tower up with the antenna on it.

Does anyone have and suggestions???

http://i43.photobucket.com/albums/e3...50/Antenna.jpg

http://i43.photobucket.com/albums/e3.../Antenna-2.jpg

http://i43.photobucket.com/albums/e3.../Antenna-1.jpg

JB Antennaman · 02-09-2010, 07:01 AM

The last few days with storm fronts moving across the east coast we have been experiencing some tropo reception. I would attribute that to your reception 120 miles away more then a antenna on a stick.

The problem with your design is that it is not rigid enough for outdoors use. The first high winds and it would flex and short itself out.

02-08-2010, 06:00 PM	#1
Gary350 High Definition is the definition of life. Join Date: Jan 2010 Posts: 77	New Improved Antenna Design working Great so far. I am redesigning my 16 element collinear array antenna again. Here is what I have learned from reading the Amateur Radio Antenna book. Book says a dipole antenna is 75 ohms and it has a gain if 2.15 db per element. 4 dipoles in parallel have a gain of 8 db. Book says several dipoles can be connected in parallel as a single element. If a dipole is made up of 3 different length elements each designed to pick up a different frequency a single element can be used to pick up all 3 frequencies. Book shows pics of 16 element dipole elements in a 16 element array. Book says bowtie elements have a slightly better gain than a straight element. Book says a long antenna can be coiled to make the physical size shorter the antenna still acts like a long wire antenna. Book says reflector screen should be .2 wavelength from the elements. I did not build it like that but it is possible to do it that way. The elements would each have to be in different locations starting with the highest frequency element closest to the screen. So far so good. I have dipole elements on each of my 4 antennas arrays. So far I have changed 4 of the 16 elements to, 608 MHz, 482 MHz, 186 MHz, 554 MHz. So far so good channel 8, 17 and 28 are FINALLY coming in at 90% strength again. I made a change the a few days ago these 3 channels dropped to 25 to 55% mostly unwatchable. So far it seems to be working. I am still receiving channel 7 in Knoxville about 120 miles away which I think it totally amazing. The signal must be a reflected signal off of a house because the back side of my antenna is facing Knoxville. I am still experementing. I plan to change this again after I learn a few things. I need the antenna to pick up all 8 frequencies so I need a design so each element contains 8 different length dipole elements each being spaced .2 wavelength from the screen. I am going to build a metal frame just as soon as I learn what I need to know and get all the channels coming in good. The antenna is bolted to the side of the house now with a 2x4 lumber support system. I picked up 30 feet of 2" diameter pipe for a 30 foot tower. It will need some wires to hold it ridgid. I think it will be a problem to stand this tower up with the antenna on it. Does anyone have and suggestions??? http://i43.photobucket.com/albums/e3...50/Antenna.jpg http://i43.photobucket.com/albums/e3.../Antenna-2.jpg http://i43.photobucket.com/albums/e3.../Antenna-1.jpg Last edited by Gary350; 02-09-2010 at 11:05 AM.

02-09-2010, 07:01 AM	#2
JB Antennaman High Definition is the definition of life. Join Date: Jun 2009 Location: Pennsylvania Posts: 947	The last few days with storm fronts moving across the east coast we have been experiencing some tropo reception. I would attribute that to your reception 120 miles away more then a antenna on a stick. The problem with your design is that it is not rigid enough for outdoors use. The first high winds and it would flex and short itself out. __________________ I feel like the mayor of retard's ville..