Arnie Coro 'broomstick' antenna -results?
Vinnie Vidivici
try making one of these with 500' of wire and some PVC pipe and I'm
wondering if it really works well.
I'm not a ham so it's for receiving only. I'm trying to dig out
stations in South America and Africa, I live in California.
What's the aluminum disk on top of the antenna for? Will an aluminum
pie plate work?
MrTimNebo
out and up kinda high and then hope for mircales to get africa good from the
west coast on any regular basis.
Diverd4777
<v...@vvv.net> writes:
>Has anyone made Arnie Coro's broomstick antenna? I've been wanting to
>try making one of these with 500' of wire and some PVC pipe and I'm
>wondering if it really works well.
Broomstick antennas are for where you don't have room for ANY external antenna;
-
>
>I'm not a ham so it's for receiving only. I'm trying to dig out
>stations in South America and Africa, I live in California.
>
Better take the 500 feet of wire
string half out East - West ( for South America )
Take the other half, string it out North - South ( For Africa)
& switch between them , depending on what you want to try to receive..
>What's the aluminum disk on top of the antenna for? Will an aluminum
>pie plate work?
" Capacitance hat" ..
Dunno how it works, play arpund with the antennas & see what works!
>
Jeff Santee
"Vinnie Vidivici" <v...@vvv.net> wrote in message news:arumev0rverdmivp7...@4ax.com...
I made one with 300' of wire and I was less than impressed, disappointed
would be a better choice of words. It just didnt work that well at all. All you end
up with is a large inductor. A slinky antenna with a MLB on it works better.
Jeff
Pabst
donut
news:JXQGa.996664$Zo.226311@sccrnsc03:
I built it and it is as noisy in my noisy environment as any wire antenna,
with less gain.
Telamon
donut <no...@none.com> wrote:
This is not a good design. It is not easy to get it to work well. The
longer the coil is made the better it will work. The larger the space
between turns the better it will work. An important factor in getting
this design to perform is to give RF current a place to go at the far
end (the top) of the coil. No problem at the other end where you connect
your radio. At the top you need a "capacity hat" for the alternating RF
current to move in and out of. Some people use a pie pan. Those are made
of aluminum though and you might end up with a poor electrical
connection. The larger the plate at the top of the coil the better it
will work as an antenna.
--
Telamon
Ventura, California
RHF
QUESTION: Is the BroomStick a "HI-Z" Antenna ?
So does the BroomStick connect to the Radio's 500 Ohm or 50 Ohm
Connector ?
Based upon what you said, and trying to make the BroomStick Antenna
both Cheap and Simple to Build by anyone.
IDEA: Could TV 300 Ohm Twin Lead be Used to Build a BroomStick
Antenna ?
WHY? - Low Cost - Readily Avalable - Fixed Width Size ~1/3"
ANTENNA BUILDING MATERIALS:
* Use a 1.5" PVC Pipe (1.75" OD)
* 100 Feet of Twin Lead
* Ten Feet of 24AWG Stranded 'Hook-Up' Wire.
* "Top Hat" Round Metal Pie Pan 10"-12"
- - - Small Aluminimum Pizza Pan 12"-14"
HOW TO: Start the coil about one foot from one of the ends of the PVC
Pipe and wrap it Uniformly and Tightly; with out gaps and overlays;
along the PVC Pipe. Secure both end os this coil with Electrical
Tape.
WHAT IT LOOKS LIKE: This should produce a Six(6) Foot Long Antenna
Coil.
(With a One Foot Section of 'un-wrap' PVC Pipe at each end.)
NEXT STEP: Attach a One Foot Wire to the end of ONE of the two Twin
Lead 'conductors'. This is used to attach the Top Hat; and allow the
movement of the Top Hat Up and Down the PVC Pipe to "Tune" the
BroomStick Antenna; for the best signal level across the bands or for
the target band.
LEAD IN WIRE: At the 'bottom end' of the BroomStick Antenna;
determined the ONE of the two Twin Lead 'conductors' that is connected
to the Top Hat. This is your single antenna wire (the other wire is
not used. (Remember: Twin Lead was used to achieve the 'spacing
between the antenna winds.) Attach an Four to Six Foot Antenna
Lead-In Wire to this 'conductor'.
~ RHF
.
.
= = = Telamon <telamon_s...@pacbell.net.is.invalid>
= = = wrote in message news:<telamon_spamshield-4...@newssvr19-ext.news.prodigy.com>...
Telamon
rhf-...@usa.com (RHF) wrote:
> Telamon,
>
> QUESTION: Is the BroomStick a "HI-Z" Antenna ? So does the
> BroomStick connect to the Radio's 500 Ohm or 50 Ohm Connector ?
That depends on whether you are standing it up inside your place or
planted outside with ground radials. Inside your house without a ground
plane it's high Z. Outside with a ground rod with good soil
conductivity or with radial ground wires it will be low Z.
> Based upon what you said, and trying to make the BroomStick Antenna
> both Cheap and Simple to Build by anyone.
>
> IDEA: Could TV 300 Ohm Twin Lead be Used to Build a BroomStick
> Antenna ?
>
> WHY? - Low Cost - Readily Avalable - Fixed Width Size ~1/3"
<snip>
If you are going to buy 300-ohm twin lead why not make a folded dipole?
Cut a length for the band you want to listen to. About 22 foot long
would be right for the 13 and 15-meter bands. It would work OK on 16
meters and poorly on any band lower in frequency. 40 foot long would
work well for the 31, 25, 22 and 19-meter bands. One about 80 foot long
would cover 60, 49, 41 meter bands well enough.
On each end short the two conductors together. In the center cut only
one conductor about the width of the twin lead. Make the connection to
those two wires to a 300 / 75 ohm transformer that you can buy from
radio shack for a few bucks. You can use 75 or 50-ohm coax from the
transformer to your radio.
If you use the 75-ohm coax use a 25-ohm resistor in series with the
center conductor at the radio to dampen reflections, which will help
flatten the response of this antenna system.
If you use 50-ohm coax use the 25-ohm resistor the same way at the
transformer end.
Use of the series resistor will not make a big difference in either
case of using 50 or 75 ohm coax but will help on some frequencies.
The twin lead wire will not support itself with the coax hanging from
it in the center so use tie wraps at reasonable intervals to strap it
to nylon cord for support. This is a pretty cheep antenna to build that
will provide you some gain. The gain will be about 3 dB broadside to
the folded dipole. You would run it north / south to get stations east
/ west of you. This antenna will also do a much better job of rejecting
common mode local noise sources than a random wire, long wire or dipole
type antenna. It will not reject local noise as good as a loop though.
300-ohm twin lead
nylon rope
tie wraps
300 to 75-ohm transformer
75 or 50-ohm coax lead in
25-ohm resistor (not that important)
--
Telamon
Ventura, California
RHF
Thanks for the reply and all the info on a 300 Ohm Twin Lead Dipole
Antenna.
But, what I was trying to get some feedback on was: Would this
approach be a 'Cheap and Simple to Build' BroomStick Antenna that
would provide an easy method of achieving the "Spacing" between the
windings that you had mentioned in the prior post.
Oh, one more thing usually an Antenna Tuner is used with the
BroomStick Antenna to get the best results.
~ RHF
.
.
= = = rhf-...@usa.com (RHF)
= = = wrote in message news:<3ef6beca.0306...@posting.google.com>...
<RJ>
I built the Broomstick Antenna.....
Made absolutely no difference over my radios built-in whip antenna.
If you ever get yours to work, let me know how you did it.
<rj>
Chris Smolinski
station? ;-)
Telamon
> Telamon,
>
> Thanks for the reply and all the info on a 300 Ohm Twin Lead Dipole
> Antenna.
>
> But, what I was trying to get some feedback on was: Would this
> approach be a 'Cheap and Simple to Build' BroomStick Antenna that
> would provide an easy method of achieving the "Spacing" between the
> windings that you had mentioned in the prior post.
>
> Oh, one more thing usually an Antenna Tuner is used with the
> BroomStick Antenna to get the best results.
>
I was attempting to redirect you away from a relatively poor antenna.
In order to achieve the spacing you desire for the broomstick rather
than have another variable (wire) in the equation I would put notches
in the wood to hold a single enameled or plastic coated wire in place.
If you have a tape measure lay it out along the broom handle so you can
make the notches evenly spaced. Cut the notch at an angle so the wire
will fall into it as it spirals up the handle. Have some way to affix
the wire in place ahead of time at the ends and you should be able to
make a nice looking coil on the broom handle.
--
Telamon
Ventura, California
GrtPmpkin32
other wire) alongside each winding. The antenna wire and the dummy wire are
wrapped simultaneously...
It's tedious but when you're done with the coil, you remove the dummy/spacer
string/twine/wire and you have an evenly spaced coil.
But I also think you'd do better trying another type of antenna... I've tried
the broom stick design three times over the last few years, and it never made
any real improvement even with a tuner/preamplifier/preselector. I didn't see
any improvement over a random length of wire or a whip attached to the
tuner/preamp.
For the tedium and effort invested in the project, I found it pretty
unrewarding. I didn't want to give up on it though, so I tried three different
times but still, aluminum pie plate and all, it's now unwrapped and sitting in
the junk box.
One more thing, could I have used MORE "////"'s in this post? :-)
Linus
Zombie Wolf
that it has something to do with a helically wound antenna. This is a pretty
fair antenna, but you will never get a match on this with 500 feet of wire
on it ! What you really would want to do with this particular antenna would
be to wind about 1/2 wavelength of wire on it, for the center of the
frequency band of interest. the formula for determining the half-wave length
would be :
468 / freq (in mhz).
the circular disk is generally used to provide a "capacitance hat" to the
antenna, thereby lowering its angle of radiation, (and in general
reception), and to broaden somewhat the bandwidth of the antenna. Lowering
the angle of reception would be the plan for a dxing antenna, since we are
interested in signals that are at or only slightly above the horizon level.
These are the furthest away, since they are coming in nearly straight from
the horizon. The capacitance hat would not make much diff on this particular
antenna design, since it simply does not work that way. The helical coil
antenna exhibits a distributed capacitance between the turns of the coil ,
and a series inductance by nature of the coil, which has to usually be
compensated for by trimming the top coils a bit to get the antenna "tuned".
We can safely ignore the resistance in 1/2 wave of number 12 copper wire,
which is generally what is used to wind the antenna. I can think of better
antennas off the top of my head for dxing, notably a rotatable beam, maybe
with traps in it for multiple bands, mounted at as high of a location as you
can muster. These directional "beam" antennas not only provide gain in the
reciever in the desired direction, but suppress noise and interference from
other directions, thereby improving the signal to noise ratio by some
considerable amount.
When winding the helical antenna, we start with close-spaced turns at the
bottom , and gradually spread the turns a bit as we go up the rod, providing
essentially a base-loaded antenna. The last 10 or 15 turns are usually put
on close-spaced, as this gives a little bit of a top loading effect , which
helps lower the radiation / reception angle a bit. But it's not really a
DXers antenna, while the multi-rotatable beam would be.
"Pabst" <dr...@some.beer> wrote in message
news:4WWR6NYW3778...@Gilgamesh-frog.org...
bocz...@gmail.com
http://www.youtube.com/watch?v=Yb_ZmteAkF4
works well i can listen radio Russia ,Australia ,North Korea ,Radio Vietnam all over the world ,trick to it is keep it high of the ground ,about 20feet or more
Adam