First Tower Part 19 – Antennas On The Tower (System Integration)

K0XG Ring Rotator at 60 ft

Electronics and Equipment On The Tower

Well, it has been a very busy couple of weeks related to the construction of our new station, and we have made great progress. Matt and Andrew from XX Towers were at our QTH again last week, and we completed the integration and testing of all the gear on our new Tower. This included adding the planned 80m Delta Loop antenna. This post will explain the final integration process for our new antenna system, including the setup and testing in our shack.

My work for this step began with the construction of 8 custom coax cables to complete all of the connections between the antennas, electronics, and hard-line feeders on the tower. These were built from a mix of LMR-400 UltraFlex and LMR-600 UltraFlex coax and a combination of N and UHF crimp-on connectors. I also prepared 8 control cables for all the electronics and equipment on the tower.

Control Cables

Control Cables

The first order of business was to connect all of the coax cables to complete the feed lines. This work included connecting the M2 Systems 2m and 70cm Yagis to their Tower Mounted Pre-amp Systems and then connecting the pre-amps to the hard-line feeders for these antennas. We installed the phasing line from the upper SteppIR DB36 to the Custom Feed-line Breakout Box at 80 ft. This device was then connected to the DX Engineering PS2B Broadband Phasing System, which will be used to create a 4 over 4 array. The final step in the coax work was to connect both the PS2B and the Feed-line Breakout Box to the two 7/8 hard-line cables on the tower.

The two control cables for the M2 Rotator and the K0XG Rotating Ring were already on the tower, so Matt and I set up the two Green Heron Rotator Controllers at the base of the tower and connected them to their associated control cables. We first tested the M2 Rotator at the top of the tower, and it worked on the first try. We set the rotator in the middle of its range and set the controller to make this direction North. We drove a stake at the edge of our yard to point True North, and Andrew adjusted the mast to point the top three Antennas North and locked down the mast to rotator clamp.

Next, we tested the K0XG Ring with the second Green Heron controller. I decided to get a pair of Green Heron controllers in their black version, and this required the folks at Green Heron to modify their deluxe version of their controller for the K0XG Ring. On the initial test, the ring did not turn. We could tell that the relays in the ring control box at the base of the tower were being energized, but the ring did not turn. After troubleshooting with a voltmeter, we determined that the modified Green Heron controller was not supplying power to the Ring’s motor control relay. We called the folks at Green Heron, and after some checking of the jumpers inside the modified Green Heron controller, we determined that the addition of a jumper would solve the problem. We did this, and the ring worked fine!

Next, we sent the rest of the control cables up the tower to Andrew for connection to the devices on the tower. These included:

  • The control cable for the SteppIR DB36
  • A pair of control cables for the M2 Antennas 2m and 70cm Pre-amp Systems
  • The control cable for the DX Engineering Broadband Phasing System
  • The control cable for our Custom Feed-line Breakout Box

Andrew set about connecting all of these control cables while Matt built an 80m Delta Loop antenna. The apex of the delta loop is 95 ft, and the base is about 16 ft off the ground. We aimed it at the NNE, and fed in the middle of the bottom section.

Delta Loop on Tower

80m Delta Loop on Tower

The 80m Delta Loop antenna is connected to a DX Engineering 8 Port Remote Antenna Switch at the base of the tower, which is connected to the shack via a 1/2″ hard-line feeder. I am planning to add a 160m Inverted-L antenna and possibly a second Delta Loop facing ESE in the future – the DXE Remote Switch will allow us to select among these antennas from the shack. We tuned the Delta loop for resonance at 3.80 MHz for phone work. I built a control cable for the antenna switch and set the controller up at the base of the tower so we could test the Delta Loop. After completing the Delta Loop, we measured the antenna’s SWR performance and found that it has an SWR of 1.0 at 3.80 MHz 2:1 SWR bandwidth of 180 kHz – perfect!

Next, we added the connectors to the shack end of all the hard lines and setup an SWR meter at our shack entry for end-to-end testing of the antennas and feed lines.

Feedlines at Shack

Feedlines at Shack

I also connected the controller for the DXE PS2B Broadband Phasing System. We connected a 50-ohm dummy load in place of the lower SteppIR antenna to test the array phasing system and feedline breakout box. I used a 28V power supply to close the T/R relays in the 2M and 70cm pre-amps which connected their feed lines directly to the antennas, bypassing the pre-amps for testing. Finally, I connected the SteppIR DB36 controller and calibrated the DB36’s elements. After placing the SteppIR on 20m and setting the PS2B to connect to the upper DB36 only, we measured the SWR at the end of the 7/8″ hard-line at the shack entry – success, a good SWR curve!

We did have some initial problems related to a combination of reversing the feed-line connections for the upper and lower DB36s at the PS2B and a wiring error in the PS2B controller. Quick troubleshooting identified both of these problems, which were easily corrected. With this done, we verified the connection to the dummy load (future lower DB36) and tested the Feed-line Breakout System – both of which worked correctly!

The final step in the test of the tower-mounted equipment was to put the two M2 Pre-amp Systems in transmit mode and test the SWR performance of the 2M and 70cm beams at the entry to the shack. I was a bit anxious about this step as both antennas’ resonance was a little low when they were previously tested close to the ground. A quick SWR test on both antennas verified that they performed exactly to M2’s specifications with SWR over the specified bandwidth of less than 1.2:1.

Next, I connected all of the control cables to ArraySolutions Surge Suppressors at the base of the tower and made up the final control cables to the shack. This step was a big job as our tower has about 100 control leads to handle all equipment and electronics.

Control Cables at Tower Base

Control Cables at Tower Base

With this step complete, we routed the control cables through the conduits we had placed in our yard to the shack and then to the shack through the existing building cable entries.

Control Cables and Feedlines in Conduits at the Tower

Control Cables and Feedlines in Conduits at the Tower

The final step in the integration of the new Antenna system was to set up all of the various controllers in the shack and connect them to the control cables from the tower and to our radios where appropriate. We first focused on the rotators and the HF-related antenna controllers first. I arranged all of this gear in the shack and connected the control cables one by one, testing the equipment on the tower as I went. The arrangement of the controllers mirrors the location of the associated equipment on the Tower, making it easier for Anita and me to use the equipment.

Rotator and HF Antenna Controllers in the Shack

Rotator and HF Antenna Controllers in the Shack

The following table shows what the various controllers do. The SteppIR controllers on the right are interfaced with our radios so that their associated antennas automatically track the frequency of our radios as they are tuned and adjust the associated antennas to remain resonant. The controllers for the DB36 Yagis have some interesting features. They can reverse the direction of the antenna in a few seconds with a touch of a button (saving time and wear on our rotators). They also have a bi-directional mode which configures the DB36s to listen both front and back at the same time. This is a useful feature for contesting and operating on nets. The Green Heron Rotator Controllers on the left will be interfaced with our shack computers to allow our station control software to point our antennas based upon the click of a mouse. More on this in a future post.

 Feedline Breakout Controller  DXE HF Broadband Stack Controller
 Low Band Antenna Switch on Tower  Controller for Upper SteppIR DB36
 Upper Rotator (Yagis on Mast)  Controller for Lower SteppIR DB36
 Lower Rotator (K0XG Ring)  Controller for SteppIR BigIR Vertical

The other part of the controller integration step in the Shack was to connect the M2 S2 Sequencers to the M2 Tower-mounted preamp systems and to our Icom IC-9100 Transceiver. The sequencers are shown below atop our Palstar Dummy Load. These devices ensure that the proper sequence of shutting down the Tower mounted Pre-amps and switching the remote T/R relays is followed when our IC-9100 is key to transmit. These controllers also have provisions to sequence power amplifiers which we plan to add in the future.

M2 Sequencers

M2 Sequencers and Palstar High-Power Dummy Load

After some testing and a little troubleshooting work, all of the HF-related antenna systems were up and running properly in the shack. I had the chance to operate the new HF antenna systems last evening, and the performance is amazing! In a 6-hour stretch, I was able to work 5 new countries and perhaps 10 or so new band countries with a combination of the SteppIR DB36 Yagi at 100 ft and the 80m Loop. This included generating a nice pileup into Europe last evening on 40m. I am consistently getting 59+10 dB or better signal reports into Europe on 40m and have gotten a few 59 + 10 dB reports into Japan on 15m – more than I expected!

The 80m loop is also a great antenna. I am getting signal reports ranging from 59+ to 59+40 dB into Europe, and my ability to “hear” DX stations on 80m is vastly improved!

My goals for this weekend include beginning to build the second of our two SteppIR DB36 Yagi’s and hooking up and testing the 2m and 70cm Yagis.

You can read more about our tower project via the articles which follow:

– Fred, AB1OC

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One thought on “First Tower Part 19 – Antennas On The Tower (System Integration)

  1. This whole setup is nothing short of amazing. You’ve obviously done a fantastic job of planning and executing this project. It is a treasure to all of us that you’ve documented the step-by-step expression of those ideas. It won’t be long until your top of honor roll! Thanks, and keep up the good work. 73! — Scott (NE1RD)

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