N6MTS Modified 40-meter Installation and Testing

In this series of pictures, we will show some of the assembly of a 2-element 40-meter yagi originally manufactured by Force 12.  The original antenna was a 10.15.20 meter tri-bander model C4SXL, and included an optional EF240S 40-meter add-on,  The original tri-band elements were scrapped, leaving only the 40-meter elements left on the boom.  The original antenna used linear loading which consisted of a mess of wires everywhere.  Mike Staal modified the Force 12 by converting it to coil loading with several adjustments.  The end results were outstanding with a measured resonant center frequency of 7.133Mhz, in the SSB portion of the 40-meter band as I requested.

Saturday evening I had a S-6 background noise-level and made contacts with Virginia (100-watts), Louisiana (1Kw), Texas (800watts), Florida (100 watts), and a Sanger mobile (100 watts).  Every one of these stations produced a +40 over receive signal,  and they all reported my signals were about +20 over (I was running 100 watts).  Yes,  I was impressed indeed.

Here are some close-ups of the business end of the driven element.

View of the mast mounted on the tower, with a 6-meter Cubex quad antenna already mounted. The 40-meter yagi is assembled and positioned “around” the quad for mounting below it. The quad was shorter and had to be mounted first.
the 10-meter Ringo mounted on the top end mostly above the quad
view of the rotor loop the way I do it. It works like a clock spring.
This is white knuckle time as we start tilting up the tower toward vertical.


And this is a look as its all finally fully vertical. The Ringo is a bit hard to see but it’s there.
One flick of the switch and up she goes. It all stops at a rotor height of 72’, putting the top Ringo at about 85’.


Once testing is complete these antennas will replace my old antennas on my rigid tower seen here in the background. A Hi-Gain TH-6 will join them.

I would like to express my extreme thanks to Mike Stall and Larry Lion for their assistance in making this all possible.  I’m really looking forward to getting this all up on my permanent tower by the end of this summer.

If you would like to see these pictures in a larger size, I will be putting the uncut version on Google Drive as soon as I can get them uploaded.  If you’re interested, please let me know and I’ll send you a link to the folder where you can view or download the larger pictures.

Ron Hunt, N6MTS