[TenTec] cone Antenna PHOTO of how to wind them

[Mike Hyder -N4NT-]

Yeah, put the small end down -- otherwise your signal will be 180
degrees out of phase.  If this is necessary, you can talk into the back
of your microphone OR the other station can listen to the back of his
speaker but not both.  WIOU wrote about similar problems with phase in
his article in the April 1957 QST about using a ferrite loopstick
antenna 1/4 wavelength underground.

Mike

----- Original Message -----
From: "Stuart Rohre" <rohre@arlut.utexas.edu>
To: <qrp-l@Lehigh.EDU>; <AQRP@yahoogroups.com>; <k5gp@texas.net>;
<tentec@contesting.com>
Sent: Tuesday, April 16, 2002 6:55 PM
Subject: [TenTec] cone Antenna PHOTO of how to wind them


| Hi Folks,
| Thanks to Steve Weber for his prototype photo of the folded conical
helical
| antenna  on the link below:
|
| This is with the one monopole mounted, and ready for more to be wound.
I
| really appreciate his doing this intermediate version, as the four
monopole
| version gets the turns so close together, a picture does not show
clearly
| what is going on. It is not too clear with the insulation on the wires
and
| same color; but the wire toward the slant edge is the no. 10 here, and
the
| wire toward the central axis in each turn, is the no. 12.  At the
bottom,
| the no. 10 goes to coax shield, the no. 12 to coax center lead.
|
| A few notes about this pair of pictures.  The Cone will not normally
be used
| in this configuration, it MUST be over a radial plane or ground plane
screen
| at least 6 feet square to work properly.  The wide end of cone must be
up
| and small end closer to ground.
|
| The Monopoles must start witht the short, (fold) at the wide end.
This wide
| end is 16 inches diameter for either 10m model or a 20m model.  The
vertical
| axis where the coil supports join should be 13 inches high.
| The slant length of the supports over which you drill holes should be
12
| inches long first turn to last.
|
| The end of the monopole at the narrow part of cone must go to coax
without a
| balun, and the coax connections must go straight off the narrow end of
cone
| and through the ground screen before making a right angle turn as
shown
| here.
|
| Remember the wide end is parallel to ground, and ground plane.  Notice
the
| holes predrilled in between turns for the second monopole to be
threaded.
| In a similar manner, for optimum performance and match to 50 ohms, you
| should have one turn pair of the first monopole, then allow 3 pairs of
holes
| for the other monopoles.  Thus, when all are threaded, you have a pair
| terminated at the top of the cone wide part, and then wind the next
pair
| starting 90 degrees from the first start, and so on, so each
succeeding pair
| is below the pair above,  pair 1, 2, 3, 4.  Since they start 90
degrees
| apart around the wide part, they should end 90 degrees apart around
the
| narrow end, but you are going to solder all the no. 12's to coax
center
| lead, and solder all no. 10's to coax shield and ground screen, (or
| radials).
|
| Now that you have a picture, if you have any questions, please write:
| <k5kvh@arrl.net>
|
|  http://www.qsl.net/kd1jv/cone.HTM
|
|
|


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--------


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