MonstIR #1 - Installation Step #1-Planning

 
Step #1 is called planning....that right.. I need to figure out how I am going to get his MonstIR up onto my tower...
 
This is not as simple or as obvious as it would seem... It's a big (39' turning radius, 70' arms, 34' boom) heavy (225Lb) MonstIR....
 
This obvious solution .. just build it on the ground and hire a crane to hoist it into place probably won't work at my site mainly because, in spite of a 1/2 acre, I just don't have enough unobstructed space on the ground to build it...let alone bring in a crane to hoist it...
 
Also I am using a Tubular Tower  (US Tower MA-85MDP) which is not easy to climb to attach things 85' in the air BUT the tower does tilt over and it also rotates (may be bad)...
 
So far, the best idea, has come from Harvey K6QK who suggest we build it in pieces and use the rotation and tilt over to our advantage as we would be working entirely on the ground...
 
The K6QK installation process would be:
 
            1.    Construct a short boom with the driven element and first director...
            2.    Tilt the tower to ground level and install the short boom onto the tower.  Connect everthing (Coax, 16                     conductor SteppIR control Cable) - [More on connections Later]
            3.    Raise the tower sufficiently to install the boom and the Second Director
            4.    Raise the tower vertically, rotate and lower it so that Reflector End is point down
            5.    Install the Boom and Reflector
 
CONNECTORS:
    
If you follow the SteppIR Yahoo Reflector you have probably read how I have disliked the idea of using a terminal strip on the antenna to terminate the 16 Wire Control Cable and connect to the 4 - 4 wire motor control cables at the driven element. 
 
As an engineer, I have always felt the flexibility of quick disconnects was very important...And it the Case of the K6QK installation process they become essential... especially since it will be virtually impossible if we build the boom in sections to climb the tower to connect each of the motors...to a terminal strip located at the center of the boom...even if we lower the tower down to 25'...
 
The solution, of course, is to use environmentally sealed connectors.. Each motor would need - a 5 pole male and connectors (4 wires #22 AWG plus ground) and the main control cable would need a 17 pole male and female connector (16 wires #22 AWG plus ground).  Bulgin Buccaneer Environmentally Sealed Connectors - www.mouser.com 6 pole MiniBuccanneer for the motor connector and Series 400  2 x 8 Pole for the main cable would work.  Figure on a cost of about $30 per motor and about $40 for the main connectors.. or a total of about $160 to do it right...Not a lot of money in the scheme of things...  The cables would be rewired so that the quick disconnects would be near the motors rather than back at the center of the beam. 
 
The benefit of quick disconects would be that each motor and boom section could be installed separately.  The other short term benefit is that we can connect and test every motor before they are installed and know for sure that everything will work when it gets up in the air..The real long term benefit is that I will be able to maintain the beam sections separately without the need to hire a crane for removing the entire beam every time I needed to fix something...
 
Now the Ham
 
So now that I have designed the way to do it right, as a Ham, I had to figure out how to do it cheaply... So today, Harvey and I visited the surplus stores in search of connectors that might work... As luck would have it after visiting only 4 places, we found some surplus 16 Pole AMP Quick Disconnect Connectors that would do the job perfectly.. at $1.95 for a male and female pair...Well 16 pole is overkill for the 5 pole motor connections, but I will double them up and use 10 poles to make sure there is no failures..and at $1.95 for a pair I bought a few spares..plus shrink tubing .. total cost $21... It looks like I can eliminate the terminal strip completely...
 
I may need some more lengths of the 4 wire shielded motor cables and I have a lot of soldering to do, but I think I may have the right solution...

Bill NS4C - suggested that I use stackable scaffolding... In response

 

We have already looked at a Crane, a Cherry Picker and a Scissor Lift Scaffold.  Unfortunately the antenna is far too big to build on the ground... If you look at www.kleega.com/erection you will see that the tower is located very close to the house (so that the 39' turning will be at least 10' inside my property line) so that moving the completed beam near the tower would be awkward... Also the property is anything but level.  So... the Crane wont work because we have no room to construct the antenna on the ground, the Cherry Picker will work but it may be difficult to gain access to all the points on the beam.. plus we would be working 25' in the air awkwardly manipulating 35' long arms...... the Scissor Lift Scaffold actually looked to be the best solution as it would have the power to raise the boom and give us access to most of the parts of the antenna that we needed and was a stable platform...but again we are working 25' in the air...very awkward to move 35' arms...
 
Until Harvey K6QK dreamed up his solution .. which is really elegant.. and we are always working on the ground.. much safer ...no danger to anyone...and no expense for renting cherry pickers, scaffolds and scissor lifts..and much easier and quicker to get things done a ground level as several people can work on the antenna at the same time...no awkward manipulation of 35' arms as several people can hold them when needed...
 
So the K6QK method looks to be much less expensive, much less time consuming and significantly safer...what's more it should easily and inexpensively be reproducable if and when I have to take things down for maintanance...
 
Right now I am starting to work on a wiring harness with all the quick disconnects.. to save us time when we do the installation...
 
Stay tuned to this web site... I will continue to report progress and post the photo shoots as we go along...once you see the elegence of the quick disconnects, you will understand why I prefer them to static terminal strips...