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2 meter slot-cube antenna

Dec 21st 2018, 10:32

KC5EZC

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
Anyone else having problems with the build? The bill of material seems to be short a few pieces
Any help out there?

Kc5ezc
Dec 21st 2018, 11:10

W1VT

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
There is some information on the Antennas, feed lines, baluns and antenna tuners part of this forum.
Dec 25th 2018, 14:57

K1AWC

Joined: Nov 7th 2014, 13:42
Total Topics: 0
Total Posts: 0
4 Each 8.5"
2 Each 8"
2 Each 7"
2 Each 6"
2 Each 3.5"
2 Each 1"
Gap in CPVC connector is 1/8"
10 Each 90* Elbow
2 Each "T" Fittings
Dec 28th 2018, 14:56

KD0NSU

Joined: Jan 4th 2007, 10:58
Total Topics: 0
Total Posts: 0
Thanks for the update
Dec 28th 2018, 15:50

K1AWC

Joined: Nov 7th 2014, 13:42
Total Topics: 0
Total Posts: 0
probably a better detail in the antenna section...
Dec 29th 2018, 12:12

KJ7BVU

Joined: Nov 16th 2018, 19:58
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Total Posts: 0
Thank you! I was having a hard time too.
Dec 29th 2018, 19:19

W6NBC

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
I am the author of the Cube-Slot antenna. There are correct tube-cut lengths, as opposed to overall dimensions, now of qst-in-depth. Many have been successful with these. They are the length of the cut tubing pieces in my prototype. Sorry for the typos and error in the article.

There are three ways to tune the antenna: (1) shunt a little L or C across the feedpoint, a short hair pin or cap of circa 10 pf., (2) Shorten or lengthen tubes. This is more work but the best. To lower the frequency only, you can add short stubs at the corners across from the feedpoint corner. A couple inches of the tube flattened and screwed on.


If anyone finds another method, pass it alone: jportune@aol.com or thru w6nbc.com email.


John W6NBC
Dec 29th 2018, 21:29

N4CLA

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
Any chance of getting a center line drawing of all the vertical and horizontal copper pipes. This would be a great help in cutting the pipes to their correct lengths as well as what frequency this antenna was tuned to for min swr.
Dec 30th 2018, 08:37

K1AWC

Joined: Nov 7th 2014, 13:42
Total Topics: 0
Total Posts: 0
Read the Antennas' section of this Forum...I describe how they all go together.
Jan 20th, 18:02

AC8QB

Joined: Mar 27th 2014, 10:48
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Total Posts: 0
Built 2m slot and it worked.
Using MFJ antenna analyzer it tuned @ 151.5 MHz.
Going to try to tune it to 146.5 if I can. Suggestions were to use Alum foil around some legs. RF impedance of ALUM and Copper are different I am told.
As it exists it has a lot of gain over the rubber antenna, Radio gets out better even though the SWR is about 1.5.
I am also suspecting the Antenna Analyzer is off freq. too.
Jan 20th, 18:09

AC8QB

Joined: Mar 27th 2014, 10:48
Total Topics: 0
Total Posts: 0
More:
Is the antenna scalable?
Would like to make one for 70 cm.
Would like to make one for 800 mHz for cell modem.
Feb 3rd, 19:00

AC8QB

Joined: Mar 27th 2014, 10:48
Total Topics: 0
Total Posts: 0
I was able to tuen the 2 meter slot antenna to 147.5 by using aluminum foil wrapped around axially around two legs of top and bottom loop. Improved my reception of Xenia repeater.
We did a scan using a Rig Expert and we were not able to find any harmonic resonances. The sweep was from 56 Mhz to almost 500 Mhz and the only resonate point we found was @ 147.5 with foil attached.
Next wee we are going to try a couple of large Ferrite split beads so we can manually tune it in the 2 m Amature band.
Whit no foil it tuned in the center of 2 meter marine band !
More next week.
Feb 7th, 21:15

WB4EN

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
I contacted John directly and with the e-mail info he sent, I built this antenna first time out with no issues. It tunes well on 2M with a low power rig and had no problems bringing up repeaters out to about 40 miles with the HT and the antenna sitting on the picnic table. I did however change the design of the feed point to provide a SO-239 connection and added caps spaced at 1/8". That was the most difficult part of the build as I was flying blind with my design. Planning to build at least one more to use at my Repeater site as it also has excellent receive characteristics and will be very easy to mount on the tower. Enjoy!!!
Feb 8th, 13:14

W7DCF

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
As an FYI - Using the adjusted dimensions from K1AWC, I constructed the antenna but used 1/2" copper pipe clamps to attach the feed line. The antenna tuned 1:1 at 145.700 which I'm not going to mess with.
Feb 16th, 19:38

VE3DLL

Joined: Nov 28th 2014, 22:35
Total Topics: 0
Total Posts: 0
I am planning on building this antenna for a "Show and Tell" at my local clubs March meeting. I am going to follow the articles instructions but was wondering if anyone else had any updates on suggestions for the build. I can be reached at danmagill@service-tel.com.

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