Its made of RG-6, center core is cut to 2 feet, 4.625 inches. The sheild is twisted about 1.5 inches long and then crimped to a copper wire for a total length of also 2 feet, 4.625 inches. Heat shrink is covering the first part of the center conductor and the sheilds crimp. Then the sheild's copper run was tie wrapped down the length of the RG-6.
Here are pics from today when I took it apart to remove the ferrite balun:
Here are pics from today when I took it apart to remove the ferrite balun:
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
SY said:
Yes, that was one of the many tests I did about running the line perpendicularly and it did not seem to affect anything. I did A LOT of testing today and didnt put all the details in the previous post to keep it short. But while mounted outside, I did remove the tie wraps and ran the cable perpendular to the antenna....no change, still lots of staticy channels in the house.
John
Conrad Hoffman said:
Padding the input is the last thing I want to do. With a basic design like this that a million people have used, there is no way its some super duper wave picker upper thats over driving two different recievers...lol I tried this on a 12 year old Aiwa and a new HD receiver with the same results on both.
I could see that if this were some huge design 100 feet high made of 1 inch diameter silver piping..lol but its just a basic dipole.
infinia said:
No, the ferrite balun was not mounted at the junction and its easy to see why if you look at the pictures. The ground radial was tied down to the feedline and then the whole thing was put inside the pvc tube. therefore, there is no way to put any balun at the junction since the junction is in the middle of the tube. Is that an optimum design? Probably, or surely, not. But I found that none of any of that made a difference.
I took the whole thing out of the tube, removed the ferrite balun, added a coiled air balun, and made the feedline 90 degrees to the elements by removing the tie wraps, etc. None of any of that made any difference when it was mounted outside.
No matter what I did to that thing outside, it got bad reception. Even mounted way up high and not right next to anything; it makes no sense.
The only way I got good reception is putting the darn thing IN the house (even WITH the 42' run still attached). How can being lower in elevation and inside a metal sided house provide better reception than being mounted outside as shown in the pictures? I simply dont get it.
I was going for the best possible signal which is why I went to the trouble of running the 42' cable, making the mounting thing, etc. So if my signal is so great with this antenna in the house, I figured I'd be able to pick up crap in egypt while mounted outside.
My HD tuner is VERY slow, painfully slow, when the signal is weak. You hit the preset button and on weaker stations (or when the antenna isnt working...lol), it might take *seconds* longer before you actually hear anything from the speakers. Its like its 'dialing' in on the frequency. When the signal is good, it dials in almost immediately and it picks up the HD segment much faster too. That, and good FM sound in general, is why I was doing all of this.
Interesting puzzle.
Is it possible to move the antenna to a different side of the house, or a different distance from the house?
I'm reminded of phase/reflection/interference problems I've had in the car in cities..... stopped at a light and the FM reception goes bad...move car a foot or two and reception returns to normal. With your metal siding, could this be happening?
Just a wild thought.
John
Is it possible to move the antenna to a different side of the house, or a different distance from the house?
I'm reminded of phase/reflection/interference problems I've had in the car in cities..... stopped at a light and the FM reception goes bad...move car a foot or two and reception returns to normal. With your metal siding, could this be happening?
Just a wild thought.
John
VictoriaGuy said:
Yes, I thought of this too. When I 'optimized' the antenna by removing the ferrite balun, added the air coil balun right at the junction, and made the feedline perpendicular to the elements, I tested it about 5 to 6 feet away from where it was mounted outside. There was no improvement by anything i did.
I think the antenna is a homebody...it doesnt like to go outside...lol
The pad suggestion is an experiment, not something to just leave in there. How do you know what signals are around you? You don't need anything super to overload an input- a plain old dipole can do it just fine. What you really need is a spectrum analyzer, but who can afford that? Actually, the "Poor Man's Spectrum Analyzer" project is pretty decent, but way more work than you'd want to go through for this. Is the terrain around the house unusual in any way- are you in a hole or against some larger structure?
Conrad Hoffman said:
I have a Tektronix scope (and have not much of an idea how to use it...lol) Would that be helpful? And I have all kinds of really good DMM's. I just have never heard of an antenna of really any kind being able to overload an input. With that said, I have heard many kinds of inputs overloaded in regards to amplification where you hear distortion so I know very well what that sounds like. This does not sound like that at all. Distortion yes, because its "noise/fuzz", but it sounds like its very much caused from a very weak signal instead of a hot one.
Lets say the signal was in fact too hot, then wouldn't that mean that the closest, most powerful stations would be the worst? Because a couple of those stations came in decently fine and not totally over blown with distortion.
This project was supposed to provide a really strong signal to my new HD FM unit but also, since it was my first DIY antenna, I wanted to learn by it. And while I have learned quite a bit (element length equations, balun types, feedline perpendicular to the element, etc etc) I find myself coming out of this project feeling that there is some kind of black magic to something here which I know full well there is not. I know this is nothing but basic science/physics yet it didn't work.
Yes, it works in the house almost perfectly (which I can't really believe) so I'm saying "screw it" and leaving it there but it bothers me that I never figured out what went wrong. That bothers me because when I go to make my second antenna in the future (probably the one mentioned earlier in this thread) I will have this experience in the back of my head bothering me thinking I'm gonna get kicked in the *** again and not know why.
I am a problem solver by nature which is why I started this thread to see if all the bright minds in here could help me narrow it down. When problem solvers dont ever solve a problem, it irritates them
calee4nyaboy said:
so I'm saying "screw it" and leaving it there but it bothers me that I never figured out what went wrong. That bothers me because when I go to make my second antenna in the future (probably the one mentioned earlier in this thread) I will have this experience in the back of my head bothering me thinking I'm gonna get kicked in the *** again and not know why.
I am a problem solver by nature which is why I started this thread to see if all the bright minds in here could help me narrow it down. When problem solvers dont ever solve a problem, it irritates them
welp you gave it the ol-college try. I thought for sure you'd have joy if you moved the balun and fixed the pinched cable. I'm sure you'll succeed in the other omni! If you go for it. hint> be sure to move it to the majick spot before you nail it down.
Did you get the Sony XDR-F1HD?
infinia said:
Right, that IS another thing I learned: dont permanently install/run cable/etc all the stuff until you've tried it. I think that was the biggest lesson. It was my (safe) assumption that how I mounted it outside would have been better than inside.
No, I didnt get the Sony unit. I got the 'generic' Insignia unit....but at a measly 15 bucks who can blame me for passing that up. The unit works perfectly fine if given a good signal. Actually, this is quite off topic, but anyone who owns one of those should beware that putting the unit in 'stand by' mode does NOT turn the unit off. It ONLY turns the LCD screen off. All the guts, transistors, tuner unit, etc are STILL on and get HOT. Normally this wouldnt matter if the insides were built properly in regards to the heatsinks but they arent. I had to mod the hell out of it before I started using it. But that is an entirely different project.
These have a high failure rate and thats why. Well, mine wont be dying anytime soon as far as over heating goes. And when not in use, I hit the rocker switch on the back, not the stand by button.
: )
Yeah, I thought about drilling holes in the case but I didnt really wanna do that. I dunno, I might go ahead and do it to the bottom of the case, but to do it REALLY cleanly is difficult where it looks nice on the top. Especially since the top has INSIGNIA imprinted/stamped IN the metal, so drilling that would be a big pain. (angles)
The tuner component inside got pretty warm so I added one there too. I tested the temps before and after the mod. The little tiny heat sink on the lower right got to 154 degrees after being on 1 hour – too hot for my taste. After the mod, it got to 107 degrees after one hour of being on. Pencil lines in the photo was where I was marking where to drill the holes.
BEFORE:
AFTER:
The tuner component inside got pretty warm so I added one there too. I tested the temps before and after the mod. The little tiny heat sink on the lower right got to 154 degrees after being on 1 hour – too hot for my taste. After the mod, it got to 107 degrees after one hour of being on. Pencil lines in the photo was where I was marking where to drill the holes.
BEFORE:
An externally hosted image should be here but it was not working when we last tested it.
AFTER:
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
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