AntennaDuring the great WSVN, DirecTV War of 2012 my friend at work, motivated by desire to watch NFL playoff games, found plans on the internet for building an HD antenna. He was so amazed by the results, that I just had to try it as well (I only have a cable box on one TV - the one in the bedroom had a cheesy store bought powered antenna that brings in a few channels, but not much). The plans I followed are at http://www.tvantennaplans.com/ and resulted in a rather clunky first attempt: The copper ground wire I had laying around (no I didn't steal it from a foreclosed house :-) is really too big. It was hard to bend into good V shaped bows and even harder to screw it down and make a solid connection. Despite all those problems though, I was pulling in 35 channels when I tried it: Far more than I ever got with the store bought junk I was using. For the first time ever, I got a CBS station (important for football). I wanted to make a better one that was less likely to fall apart, and when looking through the junk I have laying around, I found a spool of single strand bell wire and some leftover foam board (like you'd find at an office supply store for making a display). Why not, I thought, take the somewhat flimsy bell wire and tape it into the right shape on top of the foam board? I could solder the joints to make the connections very solid, and just stick the board on a closet shelf in back of the TV. I whipped out this template and printed a copy. I drew two lines one inch apart down the center of the foam board, then used the template to punch pin holes at the ends of the bowties and point of the V, going down the foam board and poking holes for all the bowties. Now I have nice pinholes to draw lines through to show the exact layout on the foam board, and I can proceed to cut lengths of wire, leaving some extra so I can trim things exactly once I get everything together. The tricky bit was removing small pieces of insulation from the middle of wire sections, but using a boxcutter with a nice sharp new blade and a steady hand, it wasn't too hard to make small lengthwise slits in the insulation, then go around the insulation at the top an bottom of the slit, and finally, pull the now mostly loose insulation away. Using my metal ruler, I bent all the bowtie wires in the middle where the insulation was stripped as sharply as I could, then for each V, I put the pin back in the foam board to locate the point of the V and moved the wires into position along the lines of the V, taping the open ends in place and leaving the pointy end lose for now so I could solder it. Next, I threaded the connection wires through the Vs and positioned them for soldering. I used a small piece of tile under each joint while soldering to avoid melting the foam board, and got all the connections secured with solder. It was a slightly painful job, but I also managed to wrap some bare copper around the connectors on the balun transformer and get it soldered into the middle of the connection wires. Then it was just a question of laying down all the bowties flat and taping them in place to secure everything solidly. The final step was trimming the excess from the bowties so they are all exactly seven inches along the edge of the V. By the way, I didn't put a reflector on it because lots of stations are both north and south of me, but I suppose if I wanted a reflector it would be simple to glue some aluminum foil on the back of the foam board. Now I can put it on the shelf in the closet and run the coax to the TV: With this new antenna, I now get 44 channels (not all really reliable, but the TV says it recognizes 44). Here's what the TV has to say about the channels (and my notes on what I saw):
The only major network I'm missing is ABC. The TV Fool report for my location looks like this, and the ABC station I'm closest to is WLPG, but it is transmitting in the high VHF band, not UHF (and this antenna is really only good for UHF). I tried setting the length of some rabbit ears to the width a dipole calculator told me was optimal for the 192 - 198 MHZ frequency that WPLG uses (real channel 10), but the TV still couldn't see it when I switched to that antenna. So, if I really want to get ABC (and probably lots better reception on WPEC CBS), I may need to build one of these monsters: I'll have to see if I can get a piece of foam board big enough (and I may need more wire as well). Perhaps it will work if I stick it behind the chest of drawers that is under the TV... If that works, I'll then apparently need an HLSJ combiner to combine the signals from the two antennas. ... Well just for the heck of it, I tried building the giant Bowtie, and it doesn't help me pick up ABC (in fact I didn't find any new channels at all and, as expected, lost quite a few old ones). Besides that, the thing is huge. It takes up pretty much all of a 60 x 40 inch foam board panel, so even if it had worked, there wouldn't have been any acceptable place to keep it (even for a bachelor :-). This mostly confirms what I suspected - I'm not gonna get ABC over the air without a pole and a outdoor antenna, which I really don't want to fool with in a hurricane zone. I may try one of designs from here the next time I get an urge to build another antenna, but I suspect that as a practical matter they wouldn't bring in any better picture on the channels I care about (but they are still fun to build :-). Second System SyndromeOK, after reading up some more, I've decided to try the 4 bay 9 1/2 inch whisker, 9 inch bay spacing version from the above site. I've also read up about the evils of mounting directly on wood and using insulated wire, so I plan to build what may be my final antenna along the lines of this one with the antenna support put together entirely from PVC pipe and fittings. As long as I was searching for relevant information on the internet, I decided to see if there was anything about straightening copper wire, and found this gem on YouTube. I tried it with a piece of wire just now, and it wound up straight as a pin. It is really hard to believe how simple it is. Now I'm thinking about wooden jigs to make sure I glue the PVC pieces together in perfect alignment and spacing and ways to make perfect “DNA strand” twists in the ends of the phase wires... (yes, I've gone off the deep end :-). Construction has begun. Here are the initial PVC pipe parts (the Ts were 33 cents each and a 10 foot length of PVC pipe was $2, so I have lots left over to try new things): And here they are dry fit together: I picked up a cheap plastic miter box ($8 for box plus saw) which made it really simple to cut the pipe square. I clamped a piece of wood down to butt the pipe against as I cut so I could make all the same length pieces absolutely identical length. Here are the whisker wires right off the spool stripped of insulation: And here are what I swear are the same wires after being twisted a few turns in the drill: And here is a close up where you can see the ends that were clamped are a little bent, but the rest is just incredibly straight: Also got the PVC bits glued together (no fancy jigs, just eyeballs and rulers and a flat surface :-). I bent all the whisker wires... ...using this sophisticated equipment: I got a couple of 2x4 boards to set the PVC in so I could work on the face easily, and filed some small notches in the PVC for the phase wires to sit in (the phase wires, as you can see, have gotten the same drill twist to straighten them): Now I have drilled and tapped the holes (laying the edge of a washer on the phase wire and marking drill location through the center so the washer will make good contact with the phase wire once the screws are in) and screwed together all the parts, not forgetting to twist the phase wires at the top and bottom: A little bending and clipping and I really will be done. And here it is. Not exactly a good permanent home, wedged against the closet door frame with a cinder block down at the base, but it is good enough for testing: And speaking of testing, all I can say is “Wow!”. I'm now picking up 51 digital channels, and even 1 analog channel (no idea where it is coming from since we are supposed to be all digital these days). And the best thing is I even get a 5 bar signal on the WPLG ABC station from Miami now. Every major network has a powerful signal with this antenna (though it looks like a couple of channels disappeared and others changed strength a bit). Here's the revised table of channels I see:
I think this brings the tale of antenna construction to a close. I can't imagine wanting to build another one now that this one works so incredibly well. OK, one last update. Here's the mount I rigged up to move it to the very back of the closet with some boards screwed to the top shelf and a spare PVC T screwed to the boards to hold a bit of pipe stuck in the base of the antenna: |