See the unconventional antenna shown below, The whole antenna is made of two mirror-imaged Alum metal stampings on either side of a 2-cm hollow 31-cm long rectangular plastic boom. The antenna top and bottom Alum stampings make up one active element. With it I am barely able to receive some TV channels that are about 25-40 km away(depending on weather). It is just shy of what I need to receive several channels up to 40Km away. regardless of weather.
I want to completely strip the useless much larger yagi-hybrid antenna (shown below the LDPA) to salvage only the dipole and the main boom. Then I want to improve/kinda clone the smaller antenna on the big boom to get better performance than I have now only limiting bandwidth to 500-670 mHz of the Dig T2 spectrum.
I see a possible big problem in making the new antenna in that he smaller lPDA design antenna has a plastic boom and the big antenna boom is made of hollow rect. alum.
How can I improve/clone the unconventional antenna to get it to work even better?
The FDLA antenna is an unusually fabricated antenna designed for the Terrestial Digital TV band. Its two-piece construction design does not fit any conventional antenna geometry. It was initially made for indoor use but I have mounted it outside and 75-ohm coax from the antenna's front position of elements is feeding a 18 dB wideband VHF/UHF preamp through a 4:1 balun with no LTE filter, with the preamp output then feeding 75-ohm coax down to the a TV though a power power supply feed point box. This antenna is so much smaller, works so much better (was able to receive stations >25 Km versus 5 km) than the commercially made antenna shown below it:
Below: **poor performing yagi. This yagi-hybrid antenna was on fire sale to get rid of remaining stock and priced at 1/10th the usual retail price, likely because it was so often sold and returned because it didn't work well.* **
5-Ft boom, kinda 3-stacked angle Yagi antenna with 2-Ft reflectors and angled booms of 8 directors each with each boom end nearest the dipole expanding up/level to boom/down to stack together to at a 25-degree to the center main boom. Each of the 8 evenly-spaced (len=13cm) director elements has a half-wave wavelength >1000Mhz. The dipole active element is two separate closed loops on either side of the boom, the resulting modified 1/2-wave dipole(approx ~400mHz half-wave) make up the single dipole that is the only active element. See Image: The split dipole is two closed loops with the bottom of the loop split to opposite sides of the main boom and feed the LTE filter (A PCB 2-cm sq. which has two holes for screws connecting the two split dipoles, these connections are approx 2-cm spread apart) and long threaded screws connect each of the dipole halves to the LTE filter PCB mounted inside a plastic box that itself is clamped to the 5-ft boom.
The dipole is positioned about 1/4 wavelength(@500mHz) from the reflectors and 4.5 cm behind the triple array of 8 identical directors on three booms, folded together and placed about 4.5cm forward from the dipole active element.
This large antenna works very poorly(with/without) the same preamp, barely better than a single folded-loop dipole(550mHz 1/2 wave)soldered directly to the ends of a 75-ohm coax cable going to the same preamp to the TV receiver.
- This antenna is made of two stamped aluminum sheets with top and bottom mirror imaged. What type of antenna is this and why does it outperform a large 3-boom kinda Yagi so well?