OldITguy
16-Sep-2014, 2:36 AM
Good day all! If you can spare some cycles I would love some advice on helping me select an antenna (or possibly diagnosing an existing one). I’ve made a few attempts already that haven’t met with success. Sorry for the oncoming tidal wave of text…
First off, my TVFR: http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3dd243f6c3f6527a
In short/tldr: My goal is to receive real channels 8, 10, 12, 43, and 40 on a single DTV sitting in the shadow of a mountain; for reasons unknown, getting 40 has been a real challenge (which is a bummer, because they air football games). I’m thinking about getting an Antennacraft HD850, but don’t know if that is going to help.
As you can see from my report, I am only 6.5 miles from the transmission towers, and all the channels I care about are at the same heading, almost due north from me, so you’d think life would be easy; unfortunately between them and me is a mountain, which I live in the south shadow of. Looking at TV Fool’s heatmap of coverage and selecting one of the above channels, I can see that only a few hundred feet to my west my neighbors luxuriate in line of sight to the tower (“red” on the heat map), while only a few hundred feet to my east my neighbors are even worse-off, in a “green” area of the heat map; I am in a “yellow” zone.
Using a RadioShack 15-246 rabbit ears antenna placed outside, the face of it pointed at ~345 magnetic, and connected with about 10’ of existing through-the-wall coaxial cable to my TV I was able to tune in a few channels (10, 12, and some undesirable others I’ve forgotten; I started with the rabbit ears inside and that only brought in 10 and I think 12). I tried pointing it west instead of north, at a hill across the valley where I suspect I’m getting reflections (TVFR says “1Edge” for most of my channels?), but I got squat. A couple of things I may have failed on here and only later learned: I had the VHF elements fully extended in a “V” shape instead of flattened out; and I used a smartphone compass app for determining bearing instead of an actual compass.
My father in law gave me an unknown-brand large-ish outdoors antenna he had for decades - a little oxidized, but appears to be an “all band” one (it looks almost exactly like the “all band” one at http://www.kyes.com/antenna/pointing/pointing.html). It is 70” long. Hooking it up outside (placed on the ground in my front yard– I don’t have a mast yet) to the same coax, connecting a Radio Shack 15-1140 matching transformer to it, and pointing it at ~345 magnetic, I was able to get all of the desired channels except for 40, and surprisingly I also lost channel 8 compared to the rabbit years. Maybe it would do better up higher… or maybe oxidation on the rivets of the elements is a problem… I don’t know.
Note, my TV has no signal meter – either it tunes the channel or it doesn’t – I have no way of knowing if I am “close” to getting a channel.
In what was probably a dumb move, I then returned the rabbit ears and balun to Radio Shack and now I have no test apparatus. /:
My novice plan before I posted this was (is?) to get an Antennacraft “heavy duty” series like the HD850 or HD1200 (the HD18xx are awfully big and the neighbors will balk at it, but if I have to do that, so be it). I was thinking the HD series because there’s the occasional doug fir tree in my neighborhood that will blow a 1” diameter branch diagonally down onto my roof in windstorms, and maybe the stronger elements in the Antennacraft HDs would resist damage… all-band (in case a future channel I want is on VHF-L)… and I was going to mount it on my roof (at about 25’ AGL) which will clear my neighbor’s house but when aimed at ~345 magnetic be pointed at the south face of the mountain. I was going to use an eve mounting bracket with a humble galvanized fence-pipe mast, giving me about 60” of horizontal space from my chimney (which is also on the north wall, and of course right next to the TV location). I was even going to drive a spare ground rod/grounding clamp/10ga bare copper I have into the soil below, as GroundUrMast and the various outdoor antenna-manual PDFs I’ve downloaded seem to clearly indicate I should do. (:
But these are all the plans of someone who doesn’t really know with certainty what he’s doing, and for all I know the HD850/HD1200 won’t pull in 40 (or 8?) either - but I wouldn’t know that until it was installed, the way I’m going.
Any advice is appreciated re antenna selection, placement, my testing techniques, mistakes I’m obviously making, misinformation I obviously believe, etc. I’m kind of hoping this learning experience will kindle some future ham radio experiments.
Sorry for the long post; maybe the details will be relevant.
Thanks!
-OldITguy
Follow-up questions: Should I point it at the towers despite the mountain, or at where I thought reflections were coming from?
First off, my TVFR: http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3dd243f6c3f6527a
In short/tldr: My goal is to receive real channels 8, 10, 12, 43, and 40 on a single DTV sitting in the shadow of a mountain; for reasons unknown, getting 40 has been a real challenge (which is a bummer, because they air football games). I’m thinking about getting an Antennacraft HD850, but don’t know if that is going to help.
As you can see from my report, I am only 6.5 miles from the transmission towers, and all the channels I care about are at the same heading, almost due north from me, so you’d think life would be easy; unfortunately between them and me is a mountain, which I live in the south shadow of. Looking at TV Fool’s heatmap of coverage and selecting one of the above channels, I can see that only a few hundred feet to my west my neighbors luxuriate in line of sight to the tower (“red” on the heat map), while only a few hundred feet to my east my neighbors are even worse-off, in a “green” area of the heat map; I am in a “yellow” zone.
Using a RadioShack 15-246 rabbit ears antenna placed outside, the face of it pointed at ~345 magnetic, and connected with about 10’ of existing through-the-wall coaxial cable to my TV I was able to tune in a few channels (10, 12, and some undesirable others I’ve forgotten; I started with the rabbit ears inside and that only brought in 10 and I think 12). I tried pointing it west instead of north, at a hill across the valley where I suspect I’m getting reflections (TVFR says “1Edge” for most of my channels?), but I got squat. A couple of things I may have failed on here and only later learned: I had the VHF elements fully extended in a “V” shape instead of flattened out; and I used a smartphone compass app for determining bearing instead of an actual compass.
My father in law gave me an unknown-brand large-ish outdoors antenna he had for decades - a little oxidized, but appears to be an “all band” one (it looks almost exactly like the “all band” one at http://www.kyes.com/antenna/pointing/pointing.html). It is 70” long. Hooking it up outside (placed on the ground in my front yard– I don’t have a mast yet) to the same coax, connecting a Radio Shack 15-1140 matching transformer to it, and pointing it at ~345 magnetic, I was able to get all of the desired channels except for 40, and surprisingly I also lost channel 8 compared to the rabbit years. Maybe it would do better up higher… or maybe oxidation on the rivets of the elements is a problem… I don’t know.
Note, my TV has no signal meter – either it tunes the channel or it doesn’t – I have no way of knowing if I am “close” to getting a channel.
In what was probably a dumb move, I then returned the rabbit ears and balun to Radio Shack and now I have no test apparatus. /:
My novice plan before I posted this was (is?) to get an Antennacraft “heavy duty” series like the HD850 or HD1200 (the HD18xx are awfully big and the neighbors will balk at it, but if I have to do that, so be it). I was thinking the HD series because there’s the occasional doug fir tree in my neighborhood that will blow a 1” diameter branch diagonally down onto my roof in windstorms, and maybe the stronger elements in the Antennacraft HDs would resist damage… all-band (in case a future channel I want is on VHF-L)… and I was going to mount it on my roof (at about 25’ AGL) which will clear my neighbor’s house but when aimed at ~345 magnetic be pointed at the south face of the mountain. I was going to use an eve mounting bracket with a humble galvanized fence-pipe mast, giving me about 60” of horizontal space from my chimney (which is also on the north wall, and of course right next to the TV location). I was even going to drive a spare ground rod/grounding clamp/10ga bare copper I have into the soil below, as GroundUrMast and the various outdoor antenna-manual PDFs I’ve downloaded seem to clearly indicate I should do. (:
But these are all the plans of someone who doesn’t really know with certainty what he’s doing, and for all I know the HD850/HD1200 won’t pull in 40 (or 8?) either - but I wouldn’t know that until it was installed, the way I’m going.
Any advice is appreciated re antenna selection, placement, my testing techniques, mistakes I’m obviously making, misinformation I obviously believe, etc. I’m kind of hoping this learning experience will kindle some future ham radio experiments.
Sorry for the long post; maybe the details will be relevant.
Thanks!
-OldITguy
Follow-up questions: Should I point it at the towers despite the mountain, or at where I thought reflections were coming from?