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I am presently running an Elecraft K3 with a beam for 6-20m.   For 10-160m,  an inverted "L"antenna is used.  This antenna is suspended 40 feet above a 20 x 40 foot metal shed. The wire is fed by an auto tuner that is mounted and grounded to the shed. The metal shed makes a great ground, the only downside is that the shed is 300 feet from the shack, making for about 3dB of coax loss on 10 meters.

12/12. Built a 3 element 17m Yagi and hung it from a line suspended between two trees.  It is steered by a anchor line running from one end of the boom to a sawhorse on the the ground. I love the front to back ratio of this antenna, but running outside to change the heading is getting old. Field strength measurements were made by parking a mobile receiver a mile away and recording the S meter while rotating the antenna. The receiver was then connected to a calibrated signal generator to determine the power required for a given S meter reading. The front to back ratio measured 21 dB, about 4 dBmore than the calculated 17 dB. Perhaps this is due to reading the signal at ground level rather than at the elevation angle of maximum gain.

The 17 meter 50 Ohm Yagi dimensions:

Reflector334 inches

Director300 inches

Driven318 inches

Reflector to driven spacing 84 inches

Director to driven spacing 65.75

Swr < 1.4:1without matching network. Note that this Yagi was optimized for best SWR. No matching network is used. Measured from the center of the boom,the first 60 inches of each element is 0.875 dia., and the remaining lengths are 0.663 dia.

11/13.   Installed a 55 foot crank-up, tilt-over tower with a Steppir 3el mounted on a tilt plate so all antenna work can be done at ground level.  On the air testing showed that the Steppir has about a half S unit more gain than the hombrew 17m Yagi.

6/14  Rope holding 17M Yagi parted converting the antenna into copper and plastic scrap.  The rope,  from one of the big-box stores, was not UV resistant.

9/14  Experimental 40M loaded dipole with matching network. 

 

This antenna seems to work very well on local and transatlantic DX while only sitting 6 feet above the ground.   The PVC is 1.5 inch,  coils ( 16uHy) are 27 turns of #12 close wound. Tuning is done by sliding a shorted turn in the coils.  A C-L-C PI network is used to match the 10 ohm feedpoint resistance of the antenna to the 50 ohm coax. Tx capacitance is 1880pF,  L is 0.363 uHy,  and antenna side capacitance is 3600 pF.   The antenna elements are 102" CB whips.  Bandwidth is around 30 KHz at the 1.5:1 SWR points and 1:1 at the center frequency.   

 

 

 

2/15   40M double "L" wire beam

Now working on a two element vertical beam for 40 meters using a passive reflector. The  antenna resembles two L's (LL),  with the lower elements 7 feet above ground.  Vertical elements are suspended from a line between two trees.  Initial tests involving a qso with a mobile indicate 6-10 dB gain over the shed antenna and a beamwidth of about 90 degrees. 

6181679 Last modified: 2015-07-16 00:21:58, 3368 bytes

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QRZ Logbook Summary for - AJ4YN
Latest Contacts for AJ4YN at QRZ.com
dedateband mode grid Country op
W1TAM 2016-07-29 6m SSB FN34jm United States TODD A MYERS
AC9KU 2016-07-24 20m SSB EN61cx United States GEORGE J ZARDECKI
MX0TBG 2016-07-24 17m SSB IO91cl England MX0TBG Team Thunderbox Group
KD2HDZ 2016-07-21 20m SSB FN30lv United States GLENN J GIANINO
AA0AW 2016-07-21 17m SSB EN36vq United States DOUGLAS J NELSON
VE3FJN 2016-07-13 17m SSB FN03cc Canada Colin Wilson
TM0QSM 2016-07-08 17m SSB IN88xp France TRANSAT Qubec Saint-Malo
PY5QW 2016-07-07 17m SSB GG54fo Brazil VIGAND OLSSON
ZD7VC 2016-07-07 20m SSB IH74db St Helena Island BRUCE R. SALT
W3HNK 2016-07-05 20m SSB FM29bt United States JOSEPH L ARCURE JR
DJ7WW 2016-07-02 40m SSB JO42of Germany Peter Voelpel
VE3CX 2016-07-01 20m SSB EN58fm Canada Tom O Haavisto
NY2PO 2016-06-30 40m SSB FN21ol United States Patrick J Cahill
KB1HQS 2016-06-30 20m SSB FN43VP08 United States Stuart H Thomas
WA2FON 2016-06-30 20m SSB FN32bs United States Marc Gorsage

Book Totals: 1456 qso's   418 confirmed Get a free logbook at QRZ.COM

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