Baker Island DXpedition from 2002 and 1993

Baker Island will be active again in a few weeks as the team KH1/KH7Z prepare for the upcoming one.  In the meantime, Dave K4SV sent us some pictures from the expedition he was part of in 2002 to Baker Island.  Dave Anderson is the tall guy on the back row.   Another ham I know is Vlad N3CZ with NCDXCC and he is in the front row on the right in a squat position.

Here is the picture from 1993 and Greer Club member  Phil W9IXX is on the second one from the right

New Antenna for 6 meters

I designed this 6m Moxon antenna using EZNEC.  The SWR figures predicted are pretty much spot on, with a dip right around 51250.   It is pretty flat across the entire 6m band with 1.8 at 50.0 and 1.3 at 54.0 MHz, although model predicts higher at the upper end of the band.  See the SWR chart below:

The SWR only follows the model somewhat around 50500 and 51000 kC and then the model diverges and shows a monotonic increase in SWR up to 54000 kC.   Both measurements track as the SWR remains below as the frequency goes up.

The gain and F/B are pretty impressive and rivals 3 element beams on gain and very decent F/B of close to 14 dB at 3.5m AGL.  The reflector is isolated from the driven elements by a couple of plastic blocks.  Overall weight of the antenna is less than 3 lbs.   It uses no transformer but will have a more predictable pattern with a choke at the feedpoint.  The following plots are for 6m AGL

The front to back is decent and actually gets better at lower heights

The forward gain is best at the height of 6m and the max lobe is at a relatively low takeoff angle.

Tried hitting the RBN with 500W of RF but no luck on getting any hits beaming northeast.

And all of a sudden a pileup - without even hitting a beacon

K0ZK, K3ZA, K1RNO, K1SX, W2SM all in rapid succession.

To those that may be interested in building it - Elements 2, 5 and 6 form the driven element and Elements 1, 3 and 4 for the reflector

All dimensions are in inches:

Element 1 - 14 ga THHN insulated - 76 

Element 3 and 4 - 5/16 aluminum tubing - 17 and 3/16 long

Element 5 and 6 - 5/16 aluminum tubing - 12 long

Element 2 - 3/4 square aluminum tubing - 42 long per half driver

The 2 half drivers are separated by an insulation block which is bolted to an insulated angle which is also the mast holder.  If you are interested in having me build it for you - contact me at ny4g@hotmail.com.  The pattern is very sensitive to the length of element 1 and this length should not be compromised.  I almost forgot that the spacing between the driven element and parasitic element is 2 and 3/16 inches.  I used 2 blocks of UHMW plastic drilled with 5/16" holes at each end leaving 2 3/16" between the holes as solid plastic.