My Homemade TV Antenna
You're at: https://57296.neocities.org/antenna.html
(last worked on: February 24th, 2021)

UHF signal search antenna

* Here's a drawing of my small exploratory antenna (on a long pole), which I made to find out if my (then) problems were due to interference or parasitic oscillations in our old, tiny, amplified, outdoor antenna. I walked our property to determine if location and height made much of a difference, finding that the signals were definitely stronger with elevation and distance away from the house.

* I got good clean signals --using just that 9 inch diameter loop of 1/16 inch bronze welding rod, a standard 75 to 300 ohm balun/transformer (that's it near the loop), a well anchored 8 foot 2x4 (for to over-build a non-conductive mast, since I ended up almost within falling distance of our home's electric power cables), 25 feet of old fashioned RG-59 cable (which I had on hand, and RG-59 is only supposed to be about a decibel worse than RG-6 for such a short run). There are two 1 inch pan head sheet metal screws to secure the antenna and balun to the end of my wooden mast. (A 9 inch diameter loop is about right for low-end UHF channels and gives fair capture area, but a directional commercial antenna is always much better for minimizing reflected ghost signals. That's what we ended up going to, on account of a big sand dune being in the way of a direct signal path.)

* Dabs of black RTV/silicon rubber over the screws and to seal the RG-59 connector to the (outside rated) balun against the weather is a good idea.

12/26/2020 updates: * For about a year I've been coping with, but not sourcing/eliminating, intermittent interference. Often it's severe enough to blank out a channel. More often it briefly obliterates the sound, displays wide horizontal tears through the picture, and calls up that blue data /"Info" field.


Mystery interference on UHF channel "#28-1"

~ The channel signal itself is always strong: 20db over fail (using my old MATV installer's step attenuator, and as indicated above by "Middle").

~ Despite that it almost exclusively occurred on our PBS channels #28-x (changed from #7-x last year), I at first I thought the television interference ("TVI") was due to our 40" "Hisense" brand flat screen going bad, but after it suffered the Black Screen of Death, our new 32" RCA TV showed the same interference.

~ Despite that I could see a wee bit of it on channels #5-x, I then thought it might be due to transmitter/translator problems. It use to get really bad around sunset, so I've also suspected someone's automatically activated outdoor lighting.

~ Since then it's been occurring well after dark and during the day, so maybe it's due to "4G" cell phone interference(?) --but a 4G/5G/LTE filter didn't help.

~ After the interference having survived two (apparent) breakdowns and restorations of our regional PBS service, and my having sent an AVI clip of the interference to Oregon Public Broadcasting's engineering, I concluded that it must be some sort of local interference --possibly our "Smart Meter" (installed a year or so ago onto our electrical power service).

~ I tried placing shielding over the Smart Meter, but to no avail. I called Pacific Power, learning that our smart meter communicates via WiFi (yours might transmit via CPL = communication over the power line), and only for 45 to 60 seconds --once per hour. That rules our meter out, since the interference here can last from seconds to 14 minutes or more, then reappear a few minutes later.

~ This interference migrated from channels 28-x to commercial channels 23-x --then back again --and with a vengeance. In the old days I used a small, battery powered TV receiver, shielded in a metal box --that had an RG-59 pass-through nipple and a minimal viewing aperture --for to aim roof antennas and source interference. I need a similar digital receiver (less than $60 at Amazon) --and my old search antenna loop (as illustrated at the top of this page).

I might also use a long length of RG-6 cable to walk my search loop around --while listening to the TVI's distinctive noise via a Blue Tooth headset.

* As of 2/14/2021, after two channels migrations, our Oregon Public Broadcasting and PBS service has been (finally) fully restored. I sent OPB a thank-you letter, but have not heard back. Presumably, the above TVI was due to problems in their equipment.

* The search loop was useful for finding the best location to place an antenna, which turned out to be a directional, commercial VHF-UHF antenna (a rather small one, out of deference to our high winds). I mounted it off of a single 2x4 mast, deck screw attached to a 4x4 porch roof support.

We ended up with 23 good signals/channels (17 solid signals remain, as of 12/30/2020). Once in a while a few of the 23 went intermittent, given our "two edged" refracted signals, lots of rain, helicopters causing phasing effects, and wind damage to the source tower.

Most of today's TV signals are in the lower end of the old UHF band, for which antennas can be small affairs (compared to those old VHF monsters --the kind that housing associations would try to outlaw with their CC&Rs). Sometimes all you need is that loop of wire --properly fed into your down lead cable.

* Our GE brand, "70 mile", VHF/UHF antenna is a puny looking thing, compared to the old Winegard and Channel Master antennas I use to install some 30+ years ago. It cost $50 locally, which included a good J-mount and a built in balun. That brought back good reception on our 4 public television channels during rainfalls. Our local channel #11-x is the actual channel (VHF high band) so we can't get by with a more compact and more directional UHF only antenna.

* Again: all of our channels are "one edge" or "two edge" refracted reception here, meaning the signal has to climb and bend over interfering terrain (mainly: the big sand dune here).

* When our local Radio Shack died I got a deal on 25 feet of "quad shielded" RG-6 down lead cable, so I broke down and replaced the old RG-59 --not expecting much difference --but the station count went up to 23! (Since the down lead is rather short, a low noise pre-amp probably wouldn't help much --unless it happened to be superior to our TV set's front end/tuner.)

** But after I got back our PBS channels, we got to watch weeks of infernal fundraising! (Those shameless beggars want your credit card number, a direct route to your bank account, they want your car, they even want to be in your will --sheeesh!)

* The best resource for guestimating what channels you can get use to be "TV Fool", but all such services, including what the FCC offers, appear to be out of date. With actual channels differing from display channels, so many repeaters/translators, and ownership cross-overs, it's difficult to nail down which channels are which. My suggestion is that you simply see what channels come in, write down the displayed call letters, then use Wikipedia to work out which is which for your location. Hopefully, most of them come from the same direction.

* Charter^ was charging nearly $55/month here for stand-alone Internet access, and nearly $30 (each) if combined with two other services (phone and Internet, at the same rates) --for about $90/month total. Presumably, each of the other services, alone, take that higher rate. So that's what we we're saving by troubling to put up an antenna --every month. We trouble to access the Internet via free public WiFi --for news, email, and maintaining our 40+ web pages --which are all freely hosted at NeoCities (for which, we freely donate). For that 3rd service of telephone, we use a Tracfone, which costs us about $10/month --depending on use.

We bought our old CDMA band, flip type cell phone for something like $10 to $15, since CDMA technology seems to work everywhere --even here behind the big dune, but you can't get that type anymore. Hopefully, you have good 2G, 3G, 4G service where you live, good broadcast TV and plenty of public WiFi signal choices.

Be sure that you use a friend's private (password secured) WiFi when buying stuff or doing banking. (We do zero banking via the Internet.)
 

--Craig

^ Even though the fine print cites "Charter Communications" on my latest Internet service offer (March, 2018), the big print is doing business as "Spectrum". The printed offer states that my "address" is "prequalified" to be connected for only $14.99/month, but an earlier such offer indicated that becomes about $20/month to include a WiFi router. (Our Chromebooks are WiFi only). When I asked about these offers at the local Spectrum office, one representative said we'd get "means tested" (which usually means there needs to be a young student or someone in the house on some type of assistance --which is not the case here), but the other implied we wouldn't. When I asked how long that price would last, his answer: "until there's a price increase".