My antennas, Mk. IV.
I’m finally moving toward free television, again. The setup you see here is the fourth configuration I’ve tried here, and it’s still not right. Over-the-air television reception seems more art than science, with a generous dose of trial and error.
Previous to what you see here, things were dead-simple. I had a single antenna, which is the bottom one in the photo. It’s pointed directly at the Toronto transmitters, which are 68 kilometres away. I also want to receive the Buffalo stations, but those vary between 14 and 62 kilometres distant. Because most of them are very close, I was hoping to receive them despite the antennas not being aimed at them. In fact, they’re located between 120º and 150º off axis. The results vindicated my plan. The signals were easily strong enough, but the strength wasn’t the problem. I believe there was a multipath issue because without exception, the Buffalo stations were strong, but suffered a signal drop off every few seconds.
What you see here is my answer to this problem. The big antenna is taking care of Toronto, and a smaller antenna attends to Buffalo. It was a good idea, but it brought another problem. The second antenna made short work of the Buffalo stations, resulting in a signal strength and stability I’ve never seen before. The problem is that the smaller antenna receives enough of the Toronto signals to interfere with those signals from the other antenna. I believe it’s a phasing issue in which one signal subtracts from the other, resulting in a far weaker signal. I believe that there are two significant causes. One is that I combined the signals from both antennas and brought them into the house on the same cable. This allows them to interact with each other, in either good or bad ways. The other is that the antennas are different. When combining signals, the general rule is the antennas should be the same.
There are two remedies I can try. I can replace the big antenna with a twin of the smaller one. This could clear up the problem but I really doubt it will. My reasoning is that the big antenna, a ChannelMaster 4228, is simply a melding of two of the smaller antenna, a ChannelMaster 4221, side-by-side. The other option is to separate the signals. If I bring in the signals from each antenna on a separate cable, the signals can’t interfere with each other. I know the Toronto signals can come in just fine, because they did before I added the second antenna. I already have the cable, but I do need another signal pre-amplifier. The Toronto signals are weak to begin with, and tuner is at the other end of a 20 metre co-ax cable. A pre-amp is required to the tune of another $70.
I started pursuing over-the-air reception when I lived in Ottawa because of my absolute loathing of cable television and the companies that offer it. The loathing is still there, but I’m even more eager now because of the plethora of available stations around here. This is what I can expect to get when I’ve got everything just so:
2.1 – NBC, Buffalo
2.2 – Weather Nation
2.3 – Retro TV
4.1 – CBS, Buffalo
5.1 – CBC, Toronto
7.1 – ABC, Buffalo
9.1 – CTV, Toronto
11.1 – CHCH, Hamilton
17.1 – PBS HD, Buffalo
17.2 – PBS Think Bright
19.1 – TV Ontario
23.1 – CW Network
23.2 – Bounce TV
25.1 – CBC French, Toronto
26.1 – Trinity Broadcast, Jamestown
26.2 – Trinity Broadcast, Jamestown
26.3 – Trinity Broadcast, Jamestown
29.1 – FOX, Buffalo
29.2 – ZUUS Country Music Videos
35.1 – CTV Two, Hamilton
36.1 – CTS, Hamilton
40.1 – OMNI 2, Toronto
41.1 – Global HD, Toronto
47.1 – OMNI 1, Toronto
49.1 – The WB
51.1 – ION, Batavia
51.2 – QUBO Kids, Batavia
51.3 – ION Lifestyle, Batavia
51.4 – ISHOP Network
51.5 – QVC Televised Shopping
51.6 – Home Shopping Network
57.1 – CITY TV, Toronto
67.1 – ME TV
67.2 – THIS TV
67.3 – ME TV
67.4 – Daystar TV, Religion
Frankly, much of that lineup is of little interest to me. The shopping, kids, weather, religion, French, and country music stations will likely not make it to my final line up. Still, all the major networks are there, and the monthly costs are exactly $0. To me, the loss of the cable speciality channels more than makes up for not having to pay the monthly fee for cable.
Shawn
love it! have you considered a rotator instead of 2 antennae?
Rick
You’re not the first person to suggest a rotator, Shawn…but my preference is to avoid them. One reason is because they tend to be more expensive then a second antenna! The big reason however, is I want to do timer recordings and even if the aiming could be automated, I sometime record two shows at once, and the two stations may not be in the same direction! Getting two antennas working well together is definitely more trouble at the start, but it pays off in the long run, at least in the way I want to use them.
Shawn
keep me posted on how you progress. I would love to toss Robbers.
Rick
Will do, Shawn. If you want to do some preliminary checking however, these two sites are worth your attention: Use the TV Signal Locator tool at https://www.tvfool.com to see what’s accessible from your location. The OTA forums on digital home.ca (http://www.digitalhome.ca/forum/forumdisplay.php?f=81) have sections for most locations in North America so you can see what others in your area are doing to get which stations. If you only use two sites for your research, these are the two to choose. Also, I bought most of my hardware from http://www.saveandreplay.com/ in Toronto and my RF cables from http://www.bluejeanscable.com
Brad
I see you have the reflector on both antennas. This strengthens the signal in the forward direction by reflecting the signal but it also attenuates any signal coming from the back.
One “experiment” you can try would be to remove the small antenna, move the large one up into the higher position and remove the reflector (if the design of the antenna allows it).
It is quite possible when you were in a single antenna arrangement with the reflector in place you were acually picking up the reflected Buffalo signal off an object (like a tree or nearby building) located in front of the antenna (since the direct signal is mostly behind the reflector). This may explain the signal issue you were seeing.
I did this and had reasonable results from an antenna similar to your small one at a relatively low roof position, so your large antenna at the top of your mast may be even better!
Rick
Thanks for the thought, Brad. I’ve seen more than a few reflectorless four-bay antennas around town. I’m hesitant to do it myself however because the Toronto signals are difficult for me to pull in. My understanding is that removing the reflector will cut the forward signal significantly, so I haven’t tried it.
Part of the reason Toronto is difficult here is because the signals are coming through my back neighbour’s house, but mostly because the Toronto line-of-sight is blocked by the big hill that is Lundy’s Lane (at least between Drummond and Dorchester). I thought a 50′ foot elevation would give me a direct line of sight, but then I realized that I had accidentally type “500” for my elevation in TV Fool! Your suggestion of it possibly reducing or eliminating the multipath is compelling, however. I’ll give it a try and see what happens…
Paul Hartman Antenna
Hi Rick, Good job! Channel Master products are durable. Also the channel master 8 bay uses a matching harness to connect the two 4 bays, unlike come other brands which use a two way splitter backwards losing 3.5db on each leg. I am pleased with your honest record of your adventure. No one seems to be able to explain why two antennas work worse than one. One theory is the second antenna is receiving an inverted version of the same channel and thereby cancelling the first antenna signal, or the second signal is producing noise into the digital constellation. I like to use only one antenna which I modify and point differently at various addresses. I would like to use your story on my website. Could I share your story on my website? Yours truly, Paul Hartman