I have a new callsign VK3JA and no longer use VK3TDX. Please visit my new page for current info. Thanks!
I am USA call NF6V ex WA0ARA now retired and located in a small town 150km west of Melbourne called Elliminyt.
My antenna farm sits on a 1 acre elevated property with clear takeoff from West to East. Shown in photo above: 40 meter vertical and 80 meter inverted-L front center, 19 M high tower at the house with tribander, 6 meter yagi, 160 meter inverted-L and rhombic feedpoint. Other poles visible are supports for the rhombic array described below. Not clear in this photo is a 40 meter 3 element wire yagi supported from the rhombic wires directed to EU.
Main rig is an Icom IC-7700 with vintage Collins 30L-1 and Heathkit SB-221 amplifiers in service. Friend Patrick VK2PN (below right) is using his trusty K3 as our second rig in the 2014 CQ WPX CW contest in multi-two operation boosted with his Expert 1K-FA amplifier . Patrick is a keen CW contester and I enjoy multi operation with him. We currently hold the VK record for multi-two in this contest.
The antenna farm features a rhombic antenna designed for 15, 12 and 10 meters but it works well on 20 meters as well. Even on 40 and 80 it works within VK with it's high low band takeoff angle and near omnidirection pattern for local contacts. It was constructed based on two wavelengths per leg on 15 meters and is focused on EU per design and the pattern diagram below. The 800 ohm terminating resistor helps SWR across many bands and minimizes noise from the back side. This is a great antenna that really performs in its design direction. I advise everyone with the necessary real estate to consider one of these great antennas. If you have questions please email me.
Above are the design dimensions and on the right the calculated gain pattern for 10 meters. Notice the nice side lobe to JA! Due to the sloping hillside terrain the takeoff angle on 10 meters is ~2 degrees. Similar patterns on the lower bands with decreasing gain and increasing takeoff angles but I get good reports from EU on all bands as low as 20 meters.
Above are the full constructed dimensions of the rhombic array in blue and in red is shown the layout and dimensions of the 40 meter 3 element wire yagi suspended from the rhombic wires. Height of this array is only 12 meters above local ground so the takeoff is a bit high on 40 but the gain derived and the sloping hillside provide a good signal focused on EU, very helpful for contesting points.
The main tower (above) is about 19 meters high supporting an A3S tribander, an A50-3S 6 meter yagi and a 160 meter inverted L in addition to the rhombic feedpoint. On the lower left of this pic can be seen the feed point of the rhombic driven with ladder line. Photo on the right is the 800 ohm termination of the rhombic nicely in the clear looking to the north.
Above are the mid points of the rhombic wire. I am fortunate to be in the clear with enough room for this wire array with low local noise. Photo on left is looking toward EU, the center of the radiation pattern.
Above shows the 40/80 meter vertical and most of the rhombic wire array. Thank you to my XYL Alicja for not objecting to all this wire and pole collection disturbing her view!
I participate in most major contests so please point towards VK in the next contest so I can give you a multiplier.
Below are my top contesting achievements so far. . .
In the 2014 CQ WW RTTY DX contest my claimed score was 2,282,082 which should be a new VK record after score adjustments are calculated.
Worked all Europe (WAE) continental winner in all three modes
QSL direct*, Bureau, LoTW or eQSL
* Paper QSL policy - $2USD or IRC for direct reply. If not included I will respond by buro. I have a nice QSL to send and I want yours but I must have help with the high cost of postage from VK. Thank you! (Contest card on the right above will be sent unless you request photo card on left.)
With supportive XYL Alicja - 40km South of my QTH at Australia's 12 Apostles coastline (same location as QSL photo from above)
Thanks for the visit and I hope we can QSO soon.
Above "retro" photos - (left) 1961 as novice WN0ARA at age 15 and (right) WA0ARA circa 1962 enjoying AM and CW traffic nets!
WIA (Wireless Institute of Australia) http://www.wia.org.au
VK Contest Club http://www.vkcc.com
Pacific DXer's http://pacific-dxers.com
6748047 Last modified: 2015-09-30 22:03:26, 7612 bytes
You must be logged in to file a report on this page