I decided to put up 69 feet of Rohn 45G guyed tower. Here is a design drawing of the tower. I toiled over which antenna(s) to put on top. There are so many good antennas, but I really liked the Force 12 antennas. I almost bought the C-3XL which is three monobanders interlaced on a single boom. I then realized I could get three 4-element monobanders for each band for the same price. I don't regret this decision at all now that I've experienced the performance of the monobanders, but my choice posed some unforeseen challenges. The mast and rotator needed to support the multiple antennas added to the cost and complexity of the project.

The tower itself is built from 6 sections of Rohn 45G, a 45AG4 top section and a SB45G short base section. The top of the tower is 69 feet above ground level. The SB45G is set in one cubic yard of concrete measuring 2.5 feet square by 4 feet deep. I have the Rohn guy brackets at the 29 foot level and the 61 foot level. The three guy anchors are 50 feet from the base of the tower, each set in a concrete slab measuring 3 feet square and a foot thick and buried four feet below ground level. I used 1/4 inch EHS steel guy wire broken with insulators to avoid any possible resonance of the guy wires themselves.

The 10m and 15m yagis are mounted on a beast of a mast. It measures 19.5 feet long with a 2 inch OD and is made of galvanized 3/8 inch wall chrome-moly steel. It weighs 160 pounds! It was expensive but it should last a lifetime. I bought it from K5RC at Productivity Resources in Texas (now in Nevada). He advertises in NCJ. I have 5 feet of the mast in the tower, mounted in two Rohn TB3 thrust bearings.

The rotator for the 20m beam is the TIC Ringrotor Model 1022. I have the ring mounted a foot below the top of the tower and I had their Mast Twister accessory which reaches over the top of the tower and grabs the mast. This rotor is built to take some REAL punishment. I hope its real life durability lives up to its appearance. It was very difficult to get the ring aligned correctly, but it has now been operating well since its installation in the summer of 1996.

In September 2000, I removed the Mast Twister and installed a Yaesu G-1000DXA rotator to turn the top two antennas independent of the 20m beam.  Openings on 10m and 15m are often at different beam headings than on 20m, so this independent aiming is a welcome change.

Two days after I declared the tower complete in June 1996, I took my first lightning hit!  The grounding system and Polyphaser surge protectors worked well.  The only damage I suffered was a blown Zener diode and op-amp in the TIC rotor control box.  It was easily fixed.  I have since installed the Polyphaser rotator surge protector that was still on the table in the shack when the strike hit.

Above the 20m yagi, you can see the Force 12 EF-410 yagi for 10m at the top and the Force 12 EF-410 yagi for 15m in between. The EF-410 is at the 84 foot level and the EF-415 is at 76 feet.

Click on the picture to see a larger image.