Glen Martin 26ft Tower Install by W7IS

Here are some pictures of the tower once it was in the air and finished.  If I ever have to climb the tower for any reason, I'm thinking of lashing a 28ft ladder against it rather than climbing directly on the tower.  

w7is at 10:04:17 AM PDT Permalink | Blog about this entry |  Add to del.icio.us |  digg this This entry has 0 comments: Add your own

The best part about the Glen Martin 26ft roof tower is it requires no concrete or guys wires and the tower is made of light weight annodized aluminum.  Plus all the hardware is quality stainless steel.  So it would be maintenance free and not have a corrosion problem in coastal areas like a steel tower could have.  The bottom 8.5ft of the tower is very heavy duty and sturdy with a 40" square base.   It can be awkward to handle and would normally require using a CRANE to install it on a roof. 

Glen Martin ships a  17.5ft tower with an upgrade kit to add 8.5ft to the bottom for a total length of 26ft.    The 17.5ft tower is modified by replacing the tubular braces (at the top of the middle section) with angle metal braces.   And to those angle metal braces is added an internal X brace as shown in picture #1.  The assembly of the add on 8.5ft heavy duty bottom section is self explanatory except for the way the feet are put together per the pictures. 

Included are numerous pictures of the feet and how they are positioned.   I decided to re-drill the feet so that the holes that attach the foot to the tower were higher up on the foot (the same location as the feet for the 17.5ft tower).  That way the 26ft tower can used as a tip up tower.   With the second hole that attaches the foot to the tower being drilled after the tower has been placed upright.   As the second holes position depends on the slope of the roof or other structure your mounting the tower too.  

Glen Martin didn't provide a detailed assembly manual for adding the 8.5ft bottom section to the basic 17.5ft tower but these pictures and description should be all you need to figure it out.  

 

 

w7is at 10:44:43 PM PDT Permalink | Blog about this entry |  Add to del.icio.us |  digg this This entry has 0 comments: Add your own

When you order a 26ft roof tower from Glen Martin they currently send a complete 17.5 ft roof tower along with a modification kit to add 8ft to the bottom.   The kit requires adding some internal cross braces to the 17.5 ft section as well as upgrading some of the tubular braces on the 17.5ft section to angle metal.   It comes in four heavy boxes sent via UPS so they really did it up brown.   I found 2 of the boxes had broken open but no piece parts came up missing. 

Some assembly required is no understatement.   Be prepared to get very friendly with a 7/16" open end wrench and socket set :-)    All the hardware is stainless steel and all nuts are nylock.   So you should use  anti-seize grease on the nylon inserts or they could CCCzzz up.  All of the  nylock nuts will be on the outside of the tower, not on the inside.  That's really nutty isn't it :-)   

The 17.5 section of tower is very light and easy to handle by one person.  I elected to assemble it on two 6ft tables spaced a few feet apart so I didnt have to spend hours bending over on the ground.   If you write the sizes on the 100's of piece parts for  reference,  you will really feel stupid later :-)    Many of the braces differ in length by less than an inch.  So I spent half a day labeling all the parts. 

Dont fully tighten all the tower bolts until the entire 26ft tower is assembled together with it  lying on as flat of surface as you can find.   I found the tower bolt holes were laid out to very close tolerances but you really do need to find a 26ft long surface area that is level as possible for the final tightening. 

There was an assembly manual and parts inventory for the 17.5ft tower but no paperwork except for a crude drawing of 8ft add on section.  It took me an extra day to call the factory and have them email pictures of the upgrade so that I could make up my own assembly manual.   Hopefully at some point they will provide a proper assembly manual for the add on section.  Although I was thinking of all the job security it makes for their support group...  it took me a few brewskies to get over that hurtle :-)

The tower goes together like an erector set and I have to say putting it together was the most fun I've ever had in ham radio :-) 

w7is at 8:35:00 PM PDT Permalink | Blog about this entry |  Add to del.icio.us |  digg this This entry has 0 comments: Add your own

I have a large second story deck that is 50ft long and 14ft wide so rather than install the 26ft tower on the roof, I elected to place it at one end of the deck.   I used 8ft long 2X6's screwed to the bottom of the deck for extra support.  The feet were attached using  surplus 5/8" threaded rod in place of lag screws.   Picture shows just one set of threaded rods installed. 

w7is at 8:13:05 PM PDT Permalink | Blog about this entry |  Add to del.icio.us |  digg this This entry has 0 comments: Add your own

Ordinarily the 26ft tower is too heavy to install on a roof without the use of a CRANE.    So it's not designed to tip over like the 17.5ft tower is.   I installed this 26ft tower on a second story deck and I wanted the tower to tip over for easy installation of the Quad antenna.   

The feet of the 26ft tower are not drilled to allow it to tip over.   So I drilled new holes higher up in the foot as shown in the 1st picture.  The 2nd picture shows the modified foot on the completed tower with grounding pipe.   The 3rd picture shows the smaller foot of the 17ft tower which provides for two lag screws while the 26ft tower is set up for 3 lag screws per foot.   Rather than use lag screws, I used surplus 5/8" threaded rod to hold the tower down to the deck.

The heavy duty feet of the 26ft tower require two bolts to hold the heavy foot to the tower and the second hole is drilled in the field depending on the slope of your roof.  This is not covered in the assembly manual.   A very important step that they left out. 

w7is at 8:02:49 PM PDT Permalink | Blog about this entry |  Add to del.icio.us |  digg this This entry has 0 comments: Add your own

These four pictures show different views of the 17.5ft tower.  I left the braces that join the two sections off so that the top section could be easily removed.  That way I could place the 8ft top section  upright on a level surface in order to line up the rotator, mast and thrust bearing without having to climb the tower. I used a bubble level to level up the top section.  Then the mast was leveled  before tightening the mast positioning bolts and rotator mounting bolts.   Then pre-test the rotator for proper operation.   The 17.5ft tower section is very light and easy to handle by one person.   So I did all the assembly of it while the piece parts were sitting on two 6 ft long tables.   The hardest part was the modification of the rotator plate as it wasnt drilled to fit the Yaesu rotator.

w7is at 7:55:50 PM PDT Permalink | Blog about this entry |  Add to del.icio.us |  digg this This entry has 0 comments: Add your own

The first picture shows that the  center of the tower is re-inforced with INTERNAL cross braces in two places. As you can see, --  if you look closely at  this picture ----  looking up inside of the assembled tower.   The thing I like best about this tower is the heavy duty 8ft base section that is 40" square.  I leveled up the bottom section on the deck using a bubble level and plywood shims so that the tower was perfectly level.  Did I mention that the bottom 8ft  ---  40" square base section is like a rock !!!

 The second picture shows the  center 8ft section of tower uses light weight -- long -- tubular braces that I consider inadequate.  As you can see, the bottom section uses all angle metal braces.   If I were designing the tower, I would have used angle metal braces instead of the tubular braces for the middle section.  An easy upgrade would be to order the tower with 3 extra sets of ladder steps.  Then you could climb the tower on 4 sides and it would also provide extra support.   If you accidentally stepped on one of those long tubular braces in the middle section it would bend it and weaken the entire structure. 

w7is at 7:45:25 PM PDT Permalink | Blog about this entry |  Add to del.icio.us |  digg this This entry has 0 comments: Add your own

The Yaesu Gs065 thrust bearing fit the mounting holes at the top of the tower perfectly.   But the Yaesu G800SDX rotator didnt fit the rotator plate generic holes. The Yaesu rotator and thrust bearing are excellent designs.  The 2" mast was easy to center using the markings on the rotator housing.   I ordered the  9ft 2" medium duty aluminum mast from Glen Martin and it is both light weight and strong.   The picture shows the thrust bearing sitting on top of the rotator.   Its the best designed thrust bearing I have ever come across.   The bearings are sealed with no grease fittings.  The Yaesu G800sdx rotator is also well designed and easy to install. 

 

w7is at 7:41:47 PM PDT Permalink | Blog about this entry |  Add to del.icio.us |  digg this This entry has 0 comments: Add your own

Unfortunately the generic holes in the rotator plate didnt line up properly for the Yaesu G800SDX rotator.  So I had to widen the holes as shown in the picture.   After the mod, the rotator had just barely enough adjustment range to fit.    That problem caused several hours delay ---- trying to be sure it would line up with the thrust bearing without binding.   So it didnt all come up roses ((()))

w7is at 7:32:10 PM PDT Permalink | Blog about this entry |  Add to del.icio.us |  digg this This entry has 0 comments: Add your own

During the tower assembly,  I didnt install the braces that join the top section to the middle section.   That way the top section could be easily removed so that it could be stood upright on the deck for installation and leveling of the rotator, mast and thrust bearing.    The Yaesu GS065 thrust bearing has 4 unique fingers that are held against the mast by the adjustment screws.   That way there is no way the mast can be damaged by the eight mast positioning adjustment bolts.   After the mast was centered in both the rotator and thrust bearing, all the bolts on the rotator plate, clam shell brackets and thrust bearing were tightened.   Then the rotator was tested for 360 deg rotation.   This part was a little time consuming but it was much better than climbing the tower to fix a screw up later. 

w7is at 7:25:54 PM PDT Permalink | Blog about this entry |  Add to del.icio.us |  digg this This entry has 0 comments: Add your own