[TowerTalk] LM-354 RBC Weldment drawing error.

[Ron W8RJL]

This posting only impacts anyone using Tashjian Tower drawing RBC-54 LT Base Weldment drawing to construct their own rebar base.

In early 2010 I purchased from Tashjian Tower the four pieces of steel needed to fabricate the Reinforced Concrete Base for my LM-354 tower and requested the weldment drawing. This week I finally got around to seriously reviewing the drawing in order to review the task with my certified welder. What I discovered is an error involving the position of the ears on the third leg of the assembly. 

Looking at the weldment drawing the third leg ear (bevel to the right) is on the wrong side of the 1" rebar. The drawing shows it right of the rebar but it should be left of the rebar. If the RBC-54 is fabricated per the drawing the third tower leg (non hinged leg) will bolt up on the wrong side of the ear and the bevel will not function as intended. Some may consider this to be no big deal but the bevel was engineered to aid in guiding the tower third leg into position as the tower is raised from a horizontal position.

Today I contacted Jason at Tashjian Towers and he confirmed there is no update to the drawing dated 10/03/01 but did go check inventory and verified that the RBC-54 units on hand all have the ears on the left side of the 1" rebar.

If you want to see how it should be fabricated go look at the photos by K6DQ on his website  http://drumon.com/ham_tower4.html  Look at the 5th photo down on page 4. BTW, his photo sequence of his tower installation is excellent.

I hope this helps anyone fabricating their own base using the above mentioned drawing. I highly recommend anyone putting up a a LM-354 or similar product purchase the factory made base but in my case the shipping from CA to VA was as expensive as the base itself. Considering the time I have spent buying the ears, buying the specified type of weldable 1" rebar, hauling the tilt fixture to the weld shop to use as a jig, etc I might have been better off biting the bullet and opening my wallet ;-)

73,

Ron W8RJL