Post by Rocketman on Oct 25, 2005 14:09:40 GMT -6
Lately I have been trying various antenna designs, but I haven't had any luck. The very first QFH I built worked fine, until I painted it (spray paint). Had I known then, the trouble I'd be having now, I would have left it alone.
I disassembled the antenna, and attempted to sand off the paint. I didn't get too far before I decided to build another one. This time I used new coax, new tubing, and new elbows.
Sometimes, being a neat freak/symetrical freak can be a bad thing. The second QFH worked good, but the first one seemed to be slighty better.
So I took it down again, and attempted to redo the connections at the top. This time I used a round piece of wood. I cut off about two inches, and sanded it down to slide down into the 1-1/4'' PVC pipe. I drilled four holes, and put small screws up from the bottom. Once I had the elements in place I then used small nuts to secure the elements, and connection points.
Alright, it's straight. Now leave it alone!
I knew that NOAA 18 was about to make a pass so I propped antenna pole upside the house. As I'm waiting for NOAA 18 AOS, I hear scuffffffffffffff boom.
AH DAMN IT! Yep it fell. The wooden peg was cracked in half... and one of the elements was bent a bit. There goes my symetry. I left the cracked peg in for awhile, and did get numerous images from it.
A few days ago I was grubbing around through some of my junk when I happened to find a small piece of hard 1/2'' thick plastic. Yep [glow=red,2,300]"FLASHING LIGHTBULB"![/glow]
So I cut out, sand down, drill the four holes, and repeat the connection steps.
Results: Null is signal overhead, and to the side, FOR NO REASON! It doesn't make any sense to me why it's acting like this!
Something just isn't right. I've disassemble it again straightening even the slightest of kinks in the copper tubing. I've dremeled out the elbows for proper mating with the tubing. I accurately bent all of the four vertical helixes to match each other.
Results: Unsatisfactory!
If I had thought to take note of more than construction necessary measurements, such as lobe 1, 2, 3, and 4's maximun distance from mast, and maximun lobe to lobe distance from each of them (as a set.. 1 to 3, 2 to 4), as well other diagonal measurements, I probably wouldn't having this problem... but then again I'm not lucky...
Also to add insult to injury, no one that I've emailed has replied to my questions regarding my antenna troubles. All I want is to do is get NOAA pictures. Some people just aren't very enthusiastic about helping others.
So you see, I'm having lots of fun... BLEH!
Hell, I think I'll build a eggbeater today.
members.aol.com/k5oe/eggbeater.htm
This guy knows his stuff, maybe I should contact him.
I disassembled the antenna, and attempted to sand off the paint. I didn't get too far before I decided to build another one. This time I used new coax, new tubing, and new elbows.
Sometimes, being a neat freak/symetrical freak can be a bad thing. The second QFH worked good, but the first one seemed to be slighty better.
So I took it down again, and attempted to redo the connections at the top. This time I used a round piece of wood. I cut off about two inches, and sanded it down to slide down into the 1-1/4'' PVC pipe. I drilled four holes, and put small screws up from the bottom. Once I had the elements in place I then used small nuts to secure the elements, and connection points.
Alright, it's straight. Now leave it alone!
I knew that NOAA 18 was about to make a pass so I propped antenna pole upside the house. As I'm waiting for NOAA 18 AOS, I hear scuffffffffffffff boom.
AH DAMN IT! Yep it fell. The wooden peg was cracked in half... and one of the elements was bent a bit. There goes my symetry. I left the cracked peg in for awhile, and did get numerous images from it.
A few days ago I was grubbing around through some of my junk when I happened to find a small piece of hard 1/2'' thick plastic. Yep [glow=red,2,300]"FLASHING LIGHTBULB"![/glow]
So I cut out, sand down, drill the four holes, and repeat the connection steps.
Results: Null is signal overhead, and to the side, FOR NO REASON! It doesn't make any sense to me why it's acting like this!
Something just isn't right. I've disassemble it again straightening even the slightest of kinks in the copper tubing. I've dremeled out the elbows for proper mating with the tubing. I accurately bent all of the four vertical helixes to match each other.
Results: Unsatisfactory!
If I had thought to take note of more than construction necessary measurements, such as lobe 1, 2, 3, and 4's maximun distance from mast, and maximun lobe to lobe distance from each of them (as a set.. 1 to 3, 2 to 4), as well other diagonal measurements, I probably wouldn't having this problem... but then again I'm not lucky...
Also to add insult to injury, no one that I've emailed has replied to my questions regarding my antenna troubles. All I want is to do is get NOAA pictures. Some people just aren't very enthusiastic about helping others.
So you see, I'm having lots of fun... BLEH!
Hell, I think I'll build a eggbeater today.
members.aol.com/k5oe/eggbeater.htm
This guy knows his stuff, maybe I should contact him.
