IW5EDI Simone - Ham-Radio

///////////////////////////////////////////
Quickie Vertical

Posted: 28 Mar 2018 10:39 AM PDT
http://www.iw5edi.com/ham-radio/2603/quickie-vertical



Quickie Vertical

Hear I am sitting in front of the rig listening to everyone working CQ
World Wide, and I dont really have time for this, but I hear a few
interesting stations on 20 meters and try to call them. Trying to bust the
pile up with 100 watts and my hustler dipole is going to be difficult on
this band, so I tune up on 15 meters and there is action, and I have a good
wire beam, so I tune up and down the band and cant find a clear frequency.
Then I hear some one say that 10 meters is open. So I tune up there, and
there is a world of DX coming in. I choose a few interesting ones to call,
but cant be heard. I should have expected that, as my antenna for this band
leaves much to be desired. It is a vertical above my Hustler dipole, but it
has no effective ground plane and SWR no better than 3:1 at its best
frequency. With no time to assemble a Quad, I start thinking about a better
vertical.



Suppose I take the parts for the quad and make a good ground plane and put
the mobile whip above it. That wont take long. So I quickly assemble a
short 4 mast with a center hub and add four 8 long 1/2 diameter fiber glass
spreaders and set in on my test stand in the center of the back yard. I dig
into my portable antenna box and find an extra mirror mount (Radio Shack
variety) and mount it at the top of the mast. Oh, the bolts are too short
for the 1 mast, so I am off to the hardware for 2 bolts. I remembered that
I had cut eight #16 solid copper wires for a ground mounted vertical about
a year ago, so I unroll 4 of them and attache them to the lower bolts on
the mirror mount and tape the other ends to the tips of the spreaders. I
then tighten the wires by dropping the hub 30 below the mirror mount which
pulls the spreaders into the horizontal position and allows the radials to
drop at about 17 degrees. Quickly, I mount the Hustler 10-meter whip,
connect the coax, and check the SWR. The SWR is great, 1.1:1, but at 29.6
MHz. So I add two more inches to the stinger and recheck. That gave 28.6
MHz for best SWR which is now 1.2:1. Not bad, a total of a half hour has
passed, and the same stations are still holding the frequencies. So I start
down the list that didnt answer earlier. To my amazement I work each one
within a minute. So there I sat wishing I had time to work the contest.

To complete the story, the radials are 101 inches long. The spreaders were
at an elevation of 4 feet above the ground. Later, I raised this to a
height of 8 feet, and nothing much changed. I also tried resonators for 12,
15, 17, 20, 30, 40 and 75 meters with equally good impedance matches, but I
didnt raise them up. The table below gives the measured SWR and bandwidth
for each band. A photo of this antenna is shown below the table. As I
really didnt design this antenna, we have to call this one just plane luck.
By the way, if you want more radials, it is possible to use two hubs with
one rotated 45 degrees to the other. Add four more spreaders to get 8
radials. This might reduce the stinger lengths a little, as mine are fully
extended on a few of the bands. The 20 meter Ham Stick wasnt long enough to
get down into the CW portion of the band, so I added four alligator clips
to the tip of the stinger. This worked about the same as the Hustler, So
here is an antenna that can be set up in as little as 15 minutes once you
have the parts together. If you paint all the parts black, it is nearly
invisible at night and not objectionable by day. Note that this antenna
works fairly well on 75 meters, but does not work well on 30 and 40 meters.
Ill tell you why some time later after I figure it out.





Note, the bandwidth is the SWR bandwidth for 2.0:1, and the stinger length
is measured from the top of the compression nut. All configurations use the
Hustler MO-3 mast part, and all resonators are the low power versions. It
is interesting to note the excellent match on 75 meters. Normally, this
whip gives a much lower impedance when set on a good ground plane, so this
probably means that at least half of the power is going into the ground,
even more is lost in the loading coil, but it still works pretty well.







Quickie Vertical Antenna




Fiberglass spreaders stretch out the ground radials. Central hub is PVC. A
Radio Shack Mirror Mount supports




a 10 meter Hustler Whip all of which is supported by a Radio Shack tripod
mount for testing.








Â*








Item
Â*Quantity
Description


Â*1.
Â*1
8 1 OD fiberglass tube for mast (MGS)


Â*2.
Â*4
8 1/2 OD fiberglass tube for spreaders (MGS)


Â*3.
Â*1
Hustler MO-3 Mast section and resonator for desired band (HRO) (AES) etc.,
Ham Sticks also work.


Â*4.
Â*1
Antenna Mirror Mount, (Radio Shack) (HRO) (AES) etc.


Â*5.
Â*4
2 by 1/4 bolts (to replace those in item 4. (Hardware)


Â*6.
Â*1
Â*Versi-Hub (RFJ)


Â*6.
Â*4
1/2 Hose Clamps (Hardware)


Â*7,
Â*4
Terminal Lugs with holes large enough to pass the 1/4 bolts


Â*8.
Â*34
#16 AWG solid copper wire (Hardware, Electrical)







Article by Â*KQ6RH originally available at
http://w2so.org/projects/antennas/quickie-vertical

The post Quickie Vertical appeared first on IW5EDI Simone - Ham-Radio.