On Sun, 2 Mar 1997 16:17:23 -0600 (CST) Matt wrote:
>and I ran the ladderline about 1" or so underground.
Uhhhh... , ok. Who am I to argue if it works! But it's going to
get awful lossy when it rains. Seems to me Alabama is one of those places that can have torrential downpours. If you want stealth, try putting the line in some plastic pipe (4" best, 2" will do). The pipe is
pretty cheap, but you'll need some elbows for each end to make your
little tunnel come up out of the ground, and to make upside-down U's to
keep rain out .
Seems to me you've got a pretty neat mom (she lets you fill up her
mailbox with 70 messages from the list every night!!!). I think I'd
try the straightforward approach and bring the line directly into the
house (with a little U to dump the rain- If I seem pre-occupied with rain, just look at my address!). The non-stealth approach may cost you
some extra work in favors ("Here, mom, let me help you with that..."), but it's easier in the long run.
By the way, by making the two legs of your dipole (yes, it IS a
dipole) unequal, you are forcing your feedline to radiate. And as you
get that line close to the ground, you make the worms real happy (cold
before, now warm. Ummmm. Nice warm worms.)
....snippity snip...
>yet, blue or black insulation. Hee Hee!
Ho ho ho, yourself! Imagine that, a black and blue antenna.
You're gonna make it look like it took a lickin' in a bad winter when
it's brand spanking new. A pre-wintered antenna. I like it!
>The next antenna that I am going to try ...is a regular old plain jane diople. ...
> The antenna is for 30 meters, then when I add the aligator clips it
will
>be for 40 meters.
Why don't you save yourself some band-changing work and make a trap
dipole out of it? Do you have a way of measuring resonant frequencies
(like a dip-meter, or an Autec Antenna Analyzer)(or a real, not virtual,
elmer?)?
> The third antenna that I want to try is a 33' long vertical.
>I also got this one from a member of the QRP-L. Take 33' of wire
>and attach it to one end of the 450 ohm ladderline. Throw it up
>in a tree, then take another piece of 33' long wire and attach
>it to the other side of the 450 ohm ladderline and run it across the
>ground. I haven't had much input on this antenna.
It is just another dipole, you've just let one element get "lazy".
Keep that lower element off the ground a couple of feet, and point it
in the direction you want to hear. There was a nice little thread on
this very antenna just a week ago. Cecil said it best: it really
works by *attenuating* the signal in the direction that the lower single
"radial" ISN'T pointing, giving you some directivity. The directivity
is dependent on how high you have the thing mounted. With the single
radial only 1 foot off the ground, the attenuation off the back is only
a few db, with a bigger null of about 15 db up at 80 degrees to the rear.
If you get the thing up about 15 feet (top of vertical leg = 15 + 33 = 48' high), then that null drops down to a more useful 45 degrees, the
attenuation to the rear increases to 5 db, and the forward direction
"gain" increases about 1.5 db over the 1'-up model.
It has been said that a vertical is an antenna that radiates
equally poorly in all directions. And it's true. An Inverted V
with it's apex at 40' (and 33' legs) outperforms the above vertical
(whose tip is 48 feet up) at all angles above 19 degrees in the
vertical's preferred direction. And even at 5 degrees elevation the
inverted V is only 7 db down from the vertical, a tad more than 1 S unit. The value in this vertical, then, will lie in it's ability to "hear"
LESS POORLY in the desired direction, while the inverted V will
cheerfully flood you with lots of noise from all over. If you are
having trouble hearing the other guy, then this vertical may be your
answer. But if he is having trouble hearing you, then an inverted V
may be a better bet.
73, ; D DWink@Juno.com Dan Winkler N7IVR Seattle, WA
----------whom the gods would destroy, they first make proud ----------
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