Antenna Technical Tips

Antennas are a little bit of a black-art… And every situation is a little bit different, so one person’s solution might not work for anyone else. Rather than discuss things like “Antenna Brand XYZ is best”, I thought it would be interesting to talk about how people solved specific problems for specific situations. This way a person experiencing a similar specific problem might be able to identify a few possible solutions.

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I’m also going to kick this one off… I’m in the Philadelphia broadcast area, about 25 miles south of the primary broadcast towers. Originally I bought an Amazon Basics “50-Mile” amplified patch antenna without thinking enough about it. I did receive some stations, but not as many as I hoped. Also, signal strength was too low on all of the VHF stations, so I would lose signal when the trees outside would blow in the wind.

So I updated to an RCA ANT751R, that I placed in my attic, and coupled it with an RCA TVPRAMP1R preamplifier. Overall, this was a great choice. The antenna is only about 3 feet wide and 3 feet long. Except… I really wanted to get VHF channel 2, and there was NO signal. Not even enough to generate a guide listing. And in spite of the fact that my channel 6 (ABC) signal should be overwhelming, I only had a weak channel 6 signal that would fade out in bad weather.

Now, the ANT751R is a very nice antenna… As long as all of your channels are VHF channel 7 or above. But in Philadelphia, I have channels 2 and channel 6 I want to watch. And even the amplifier didn’t help…

As an experiment, last week I made two folded-dipole antennas and added them in my attic. One of the dipoles is tuned to channel 2, and the other is tuned to channel 6. I then added these two dipole signals together using a “combiner” transformer, and fed that combined output into the VHF input of my preamplifier. (And I’m still using the ANT751R for the UHF channels.) The result is perfect… I now get great reception on VHF channels 2, 6, and 12. (Channel 12 is easy to get in my area, so not surprising that it still works well even though I don’t have any antenna tuned for channel 12.)

My folded dipoles are made from old-fashioned 300-ohm twin-lead wire, and a couple of 300-ohm to 75-ohm matching (balun) transformers made by RCA that I picked up at Lowes. It requires a bit of soldering for assembly, and I nailed them directly to the roof-joists in my attic.

Instructions for measuring and building the antennas are here:
http://users.wfu.edu/matthews/misc/dipole.html

The overall lengths I used for each dipole are:
Channel-2 = 54-60MHz = 57MHz = 97.25 inches long.
Channel 6 = 82-88MHz = 85MHz = 62.25 inches long

As an assembly tip, I soldered the wires coming from the matching transformer directly to the dipole antenna, This is the “feed line” that he talks about on the linked page. So my folded dipole attaches directly to a standard 75 ohm coax cable.

If you over-research this you will find all sorts of people telling you why this can’t work… In my case, I have not overloaded my preamplifier, and the narrow SWR of the twin-lead antennas works to my advantage when I’m adding them together. (Just for you antenna purists out there.) It allows me to add the two different tuned-frequency antennas together without them cancelling each other out.

To combine the two antennas into a single coax I purchased a splitter / combiner from Amazon, that goes by the brand name ChannelPlus 2512 for about $12.

Overall, this is a very cheap solution that doesn’t involve putting an 8-foot wide and 10-foot long antenna on a mast outside of my house… And as long as you don’t have a requirement for a lot of gain, or the need to reject signals coming from the rear, this might work well for you… (I’m talking to you Philadelphia suburbs…)

I went through many antennas, at least 5 in my testing.

The best antenna for me was the ClearStream 4V. A close second was the Winegard Flatwave FL-5500.

http://www.bestbuy.com/site/antennas-direct-clearstream-4v-antenna-black-silver/6761173.p

Yes antenna selection and use is definitely a black art. The first antenna I tried (one of those flexible flat square antennas that costs $15) would give me five green dots for some channels and three orange dots for other channels. The antenna came with an amplifier that I had not yet hooked up. Then I inserted the amplifier into the connection, leaving the antenna in exactly the same position. Some channels that had been orange turned green (good news) but other channels that had been green turned orange or red (bad news). Go figure. But no amount of fiddling with amplifier/no-amplifier or fiddling with orientation of that antenna gave me five green dots for all of the channels that I actually wanted.

Normally when you try an omnidirectional antenna and it does not do very well for you, the next step is to try a “gain” antenna such as a Yagi. I picked an inexpensive Yagi antenna ( http://www.amazon.com/gp/product/B0024R4B5C ). It is actually two antennas in one. It has a four-element VHF Yagi antenna and a four-element UHF Yagi antenna, all pointed in the same direction. The energy from the two antennas gets combined and passes down the coax to the Tablo.

The whole point of an omnidirectional antenna is that it sort of does not matter very much how you orient it. The problem with a “gain” antenna such as a Yagi is that it really does matter where you point it. Yes you can point it toward some particular transmitting antenna and you will receive the signal from that transmitting antenna more clearly. But then some other transmitting antenna might be somewhere else and your super-duper directional antenna won’t pick that one up at all.

This is why some people will put their Yagi antenna on a rotor. They can then turn a knob and the rotor will point the antenna in the best direction for some particular channel of interest at the moment.

Where my Tablo is located (Denver area) there are transmitting antennas all over the place. Using a clock face to describe the situation, there are transmitting antennas at 1 o’clock and 11 o’clock and 9 o’clock and 7 o’clock and 8 o’clock. You can try the omni flat antenna and you will not get five green dots with any consistency across all of these various antennas. And if you pick out the half dozen or so channels that you really want (the networks that everybody has heard of) you cannot get them all with five green dots, not using an omni antenna.

Okay so next thing to try is the Yagi. But the Yagi can only be pointed in one of these directions. If I point it at 9 o’clock it will give me five green dots for one (one!) channel and no signal at all or only one red dot for the other four directions. This is where you need to really study your report from antennaweb.org. If you pay close attention to the report, you can work out that there is one direction that you can point the Yagi and it will give you five green dots for all of the channels that you really want. This is because in the Denver area there is a single hill where lots of channels have their antennas. It is at the place where Interstate 70 starts to go up into the mountains. All of the channels that you have ever heard of have transmitting antennas on that hill. (The distance from my Tablo to that hill is about 21 miles.) So a single Yagi pointed in that direction (southwest from the location of my Tablo) is able to get five green dots for all of the channels that I care about. Oh and no amplifier was needed.

Some of the antennas on this hill are at about 7 o’clock and others are at about 8 o’clock. The key turns out to be aiming the Yagi antenna at about 7:30 o’clock.

I could have spent a lot more money on a Yagi antenna with more elements (that is, a higher-gain antenna). In fact no matter how much money you feel like spending on a TV antenna, you can find some antenna that costs that much money. But a much more expensive antenna, for example a Yagi with many more elements, would only be a more narrowly focused antenna. There’s the risk that it would pick up only one antenna on that hill well and would pick up the other antennas on that hill less well. If pointed at 7 o’clock it might not pick up the antennas at 8 o’clock very well or vice versa.

The goal in this particular geographical situation was to find an antenna that was directional enough (high enough gain) to pick up the signals from the antennas on that hill, including those at 7 o’clock and at 8 o’clock, and yet not so directional (not too much gain) that it only picked out one antenna on that hill.

The flat flexible nearly-omnidirectional antenna had a gain of about 1 decibel. The Yagi antenna that ended up working well for me had a gain of about 4 decibels. The next-more-expensive Yagi that I might have tried (five or six elements per antenna) had a gain of about 9 decibels. (By the way it is hard, sometimes impossible, to get straight answers from the various antenna makers as to the amount of gain or the narrowness of the beam pattern for a given antenna. You sort of have to figure it out yourself by counting the number of elements in the Yagi antenna.)

What I am trying to emphasize in this posting is that getting five green dots for the channels that you care about is a project that is not simply a matter of spending more and more money until you achieve the desired result. Nor is it a matter of adding more and more hardware (for example adding an amplifier) since that might (perhaps counterintuitively) make things worse instead of better. In this case it was a matter of stumbling upon an amount of gain (and directionality) that satisfied a “sweet spot”. Enough gain to pick up signals from 21 miles away, but not such a narrow beam as to pick up fewer than all of the antennas on the hill that I care about.

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I am using the same antenna. Channel 2 (CBS) and channel 4 (NBC) both come in gangbusters ( 98%) signal strength. I suppose having it roof mounted some 30 ft above ground level helps. My experience with high end outrageously priced flat antennas ( Mohu leaf) was a bust. Many channels received- NONE reliably resulting in recording failures. Change orientation and some channels improve somewhat to the detriment of others. In many major cities towers are centrally located, IE same location. In this situation unidirectional Yagi antennas win hands down. Their ability to beam in precisely on the signal while rejecting noise and extraneous rf interference from other directions wins the day.

For all those listening this is a very good performer (ANT751R) and very reasonably priced. I receive over 100 channels rock solid of which I only list about 25 or so on the guide.

@JerryG - My problem with channel 2 (KJWP in the Philadelphia market) is that KJWP is using a 9.36 kW transmitter, so it’s signal levels are low in my neighborhood. Compared to channel 6 - WPVI (ABC), that’s running 30kW from the same antenna location, my reception of channel 2 was pretty poor.

I agree that the ANT751R is a great, small, and low-cost directional antenna. But I needed to do something special to receive channel 2. And having improved reception for channel 6 was a bonus for my location.

Hi
I am in Oshawa Ontario. Had no experience with OTA but wanted to try it so I could cancel my satellite subscription but also to try something different. Consulted tvfool and noted that I should be able to receive Toronto stations from the west and Buffalo from the south over the lake. Bought a 4 bay Chanel Master antenna. Mounted it on the old bell satellite arm on my chimney and using the existing coax plugged it into my tv and ran a channel scan. It worked. Was tricky to align/point the antenna so it got all the stations tvfool predicated I’d get. Considered a rotor but that wouldn’t work with Tablo. Thought about an eight bay antenna but didn’t want to spend the money. Eventually I lined it up so I received the stations I wanted - for whatever reason citytv was the hardest to get. Then I bought the tablo but quickly found live hockey through tablo is jerky so I ended up boasting the signal, splitting the coax with runs to tablo and to my two tvs and I simply watch live sports on the tv tuner.
The antenna has been good since it went in with no problems. The tablo has been a bit more variable with the most recent software release being the most reliable so far. Like a lot of people I’m waiting for the Apple TV app which should give me the system I envisioned when I started all this.
Mark

Novel solution. Yet I’m surprised the 751 couldn’t receive what your dipole did. Whatever works.

I have gone through a number of antennas and I agree with JerryG … the ANT751R has been a winner for me.

In antennas: Resonance rules !!!

I’m located in San Clemente, Ca. and have, like most everyone here, gone through a few antennae and pre-amp/amps to boot.

My current system is;
HD Stacker antenna – roof top mounted
Channel Master CM7777 Titan2 Preamplifier
PCT INTL PCT-VB-8UN RF 8 Port Amplifier
RG6-Quad Shield Coax Cable, throughout

I replaced;
Winegard LNA-200 Boost XT Preamplifier
Leviton 47690-6 1x6 Passive TV/CATV Splitter

And in the past, before switching to cable TV
Antennacraft 5MS921 Amplified Antenna – I think this was the one, it was removed when we re-roofed.

I still fight to get a solid ongoing signal of channel 28, it tends to get flakey in the late afternoon.
I’m luck, to a degree, that the broadcast antennas for LA and 2 of the San Diego stations are 180 degrees apart and so, on scan, I get 134, channels reported. Most of these are channels that we’ll never use but it replaced the cable company. We also have Netflix and Hulu, so we don’t lack for content.
Our broadband video is wired 1GigE, Roku 3

I wanted to include a TVFool.com analysis link.
Chris

Oh gosh like so many others I went thru a lot of futzing around trying to get the right combination of antennas and orientation… I first started with some crappy Mohu knockoff but being 40+ miles north of the Boston transmission antenna clusters I think I only got 1 or 2 channels… Like others here, I also picked up the RCA ANT751R and a RCA TVPRAMP1R preamp… which worked pretty well (I checked the AVSForums as they have some specific forums on OTA HD tv) … I also checked tvfool.com for the right general direction to point my antenna in… I used this setup for testing if cutting the cord was even viable and/or if we could live with what reception we got (we also live on a hill and the terrain between my home and the far off broadcast cluster south of us is also a little hilly) … With the ANT751R we got enough channels to run a test over the summer (I disconnected the cable box from the kitchen tv – arguably our most watched tv – and picked up a cheap OTA HD Tuner/DVR {the real crappy $35 chinese knockoff kind - iView 3500STBII Multi-Function Digital Converter Box} … We ran this test for a few months to see if it would work for our family… In the meanwhile I had picked up (and regretted since it turned out to the the source of my primary problems) a SimpleTV dvr… I also picked up a Antennas Direct, inc DB8e Extreme Range Multi-Directional Bowtie UHF Antenna and a second RCA TVPRAMP1R for the DB8e (I got the DB8e as I thought I was having reception issues and needed the larger antenna ) … After a lot of frustration and aggravation it turned out there was a major defect with the SimpleTV tuner and it was getting low or poor signal strength on most channels and would not even tune the local ABC affiliate station (which also happened to give the strongest/cleanest signal – when you hooked the antenna up directly to an HDTV for comparisons) … Before I discovered the major problem with the SimpleTV (I mistakenly assumed my reception issues were with the antenna, the wiring, preamp or orientation… I never actually thought the DVR itself was crap) … {oddly when the same setup was connected to a tv everything worked great, all stations we wanted were clear and strong} … I should also note there were no splits from the DB8e and the wiring was all new… I tried mounting the DB8e in the attic like I did with the RCA ANT751R and then I opted to roof mount the DB8e in the hopes that would fix the poor reception issues … At the advice of some others on the simpletv forums I tried using an HD Homerun dual tuner to check the signal strength with the homerun and a dedicated mobile app while on the roof (as I use iOS I opted for Signal GH http://genhelp.com/Generally_Helpful_Software/Signal_GH.html) with the help of the mobile app, the HD homerun dual connected to the antenna and being on the roof I was able to get the orientation perfect and verify that the antenna and the wiring was working correctly (the HD homerun tuned the tv stations just as perfectly as the HDTV did) … it was at this point I called into question the simpletv… after reading a lot of great things about the TABLO I opted to purchase one and try a 4 tuner TABLO… the results were stunning… where the dual tuner simpletv struggled the TABLO 4 tuner easily tuned in 2x more channels that the simpletv did and all of them were stable and clear… I was even able to pull in stations as far north as Bangor ME (but those are very weather dependant and there are no stations that are in Bangor that I dont have better more local affilates for) …

My only regret was I didn’t notice the DB8e was UHF only as there is one PBS station that is broadcasting on VHF channel 11 … I might explore whipping up a simple dipole and feeding it into the RCA preamp on the VHF side… but as I already get PBS im ok with not having it for now. (maybe once TABLO has the option to only record shows from specific channels I may revisit this)

Our in home setup is the wonderful Arch C7 router, and I have recently switched all hardwired connections thru a dedicated 16 channel gigabit router… we primarily use desktops with OSX, (one windows laptop), ROKU 3’s and iOS devices to view TABLO content. the Tablo is hardwired directly to the gigabit router and the ROKU devices are hardwired via HomePlug 500mbs ethernet over power adaptors… the only wireless devices are the mobile iOS devices and a couple laptops…

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They make a vhf addon for the DB8e but its a bit pricy.

I have a DB8e, however i noticed that I get more antenna related interruptions with both sides hooked up. After disconnecting one side, thing have improved although i still get some antenna related artifacts/stuttering. As it turns out the tower is 12 miles away. I show all green dots across for all stations, however i still see momentary anteanna related blips are artifacts/stuttering(no LPWs). Is it possible that my antenna is overly saturated? Is it possible to see if the tower is over powering the tablo? Is this even possible. I would kill to get some sort of antenna related feedback from my tablo. I feel as if the most important data for having the best antenna setup was somehow neglected from the system. Anyone got any ideas other than purchasing a HDhomerun?

Yea its kinda pointless for 1 PBS station when I already get 2 PBS stations…

12 miles is WAAAAAY to close for the DB8e as its rated as a 70+ mile “extreme long range” antenna…

". It has a range of 70+ miles, making it the ideal antenna choice for suburban and rural installations challenged with receiving signals through heavy foliage outdoors or roofing materials in attic installations. Using aluminum and steel, DB8e antennas are engineered for strength and durability. "

I’m out about 70 miles from Mt. Wilson, the main antenna location for LA. The biggest problem that I run into is having some comfort that I’m really getting the antenna oriented for the best signal, not always a direct compass heading to the antenna. I’ve been toying with getting the HdHomerun connect to validate that I am getting every bit of the signal that is possible. $80 seems a bit rich ATM…

Chris

@SCChris - I’ve seen this mentioned a lot of times in the last few weeks alone. I think this deserves a feature request, even if the request has been made a hundred times before. (It never hurts to remind people of things that everyone trips over frequently.)

@jberting, Agreed!.
I don’t know the specifics relative to the coding to do it, and capabilities of the TabloTV chips set to report these, but it would really be nice.

Thanks