![]() ![]() An alternative to using copper tape to make the solder connections is to use copper or brass rather than A DC connection to theĪluminium is not necessary because the capacitive reactance is small enough to be negligible. The tape that I used has a capacitance of 143 pF or 0.7 Ohms reactance at 1575.42 MHz. Since soldering to aluminium is difficult I attached a 1" square of copper tape to both the top of the patch and the bottom of the ground plane centered at the feed points where the cable should be soldered. section of RG-58/U will satisfy most applications. The next step is to attach the coaxial cable. Ground plane to a radius of about 4 mm ().157") and then bolt the patch to the ground plane. At this stage round the corners of the patch and the Then separate theĪluminium pieces and enlarge the ground plane hole at the feed point to 4.59 mm (3/16") diameter (for RG58/U coax). One means of controlling the dimensions of the pieces is to scribe the exact dimensions on theĪluminium surface, then cut the piece somewhat larger than the necessary dimensions and grind the edges to obtain the final size.Īfter the aluminium is cut to size, clamp the patch so that it is centered on the ground plane and drill the four 4.76 mm (3/16")corner holes for the #8 nylon bolts as well as the small 1.59 mm(1/16") hole in the patch for the center conductor of the coax at the feed point. The first step is to cut the aluminium sheet metal pieces needed for the patch and the ground plane. Having determined the design dimensions of the patch, we will now turn our attention to its construction. The bandwidth of the two modes of the patch are 8 and 10% respectively which means the critical dimensions of the patch shouldīe held to within about 3%. The sheetĪluminium should be at least 1.27 mm (0.05 in) thick to provide sufficient mechanical strength but the exact thickness is not critical. Separation of the patch from the ground plane is 5 mm (0.197 in) and is determined by the three No. The dimensions of the ground plane are much less critical. The critical dimensions are those of the patch and the location of the feed point. The final dimensions of the patch and its ground plane are shown in the diagramīelow. We have chosen to build the antenna using aluminum sheet and an air dielectric with nylon bolts and washers to support the patch. I can just pick it up and go walkabout.īruce Molzen E-mail: molzenba(at).za I get brilliant reception and the system does not tie up the h/h The h/h GPS lies on top of this loop, which sits on my cubbyīox/armrest. This effectively "retransmits" the GPS signal The coax then goes into the Landy and terminates in a simple loop of about two match boxes in line type size and sits about 200mm from the rxĪntenna. This amp costs about R50.00Īnd is available from any shop that dabbles in TV/sat etc. In-line amplifier with a slope gain of up to 26dB. The coax from the antenna then feeds into a wide band (0-2010 MHz) satellite It has a smaller element about 80x90mm mounted 8mm above this. The receive antenna is an aluminium "patch" GPS signals come in at ± 1500MHz, the wavelength is ☑90mm. Of my Land Rover Series 3 - so I made an external antenna for it. No, I don't want to install another outside TV antenna for the squirrels to use as a jungle gym and landing pad for Evil Kinevil jumps.I had a small h/h GPS that did not work satisfactorily when placed on the dash No, haven't tried a different DTV converter box but it worked fine till they changed their transmitting antenna. ![]() Yes, I have rescanned a couple of times with no change. So I'd like to try an antenna preamp to see if I can reduce the fiddling to get a signal on 11, the station I watch most. At times it is almost like one of those old time cartoons with the guy standing on one leg with his tongue out holding the rabbit ears so the signal is good. Well Channel 11 decided to upgrade their transmitting antenna for better signal strength which for me had just the opposite effect. It worked so well I abandoned the idea of a new outside antenna. Desperate for my TV fix I hooked up a simple bare bones rabbit ears just till I got a new outside antenna. I use to use an outside antenna with a rotor but one Sunday the squirrels finally broke it beyond repair. I don't need to split the signal and it does not have to be outdoor but under $30 is necessary.īackground. Years ago I tried one I could afford from Radio Shack and it actually weakened the signal. Is there a TV antenna preamp that really works. ![]()
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