Assembling Glen Martin Rt-424 Roof Tower

The RT-424 is a 4.5 foot tall roof-mounted tower for rotatable antennas.

As I have heard, this looks like a nice product but the instructions leave something to be desired – something HUGE. Here are a few notes and warnings from my assembly process.

Things you MUST know:

  1. There are 28 bolts, and eight of them are shorter than the others. You must use the 8 shorter bolts in the top section to secure the thrust-bearing plate. otherwise (if you use the longer ones), it will not be possible to assemble it.
  2. If you tighten everything as you build the tower from the ground-upwards, you will not be able to align the holes to attache the thrust-bearing plate (unless you are very lucky).

Some General Observations

The pieces came well packaged, with the hardware in one of those multi-section shrinkwrap bags.

The machining appears to be well done but they did not deburr the holes on my parts. Be careful, you could get a nice cut from the sharp edges.

Some Assembly Photos and Suggestions

When assembling the tower, leave all hardware loose enough that you can move around the parts, until you are ready to put on the top thrust-bearing plate. I suggest starting by attaching two-each of the cross-braces to each of the legs using the top bolt for each brace, as shown below.

Two legs with the braces attached at the top


Next attach one of the rotor plates between each pair of legs, and then attache the lower portion of the cross-braces between the two legs.

One side lower assembly with two legs, braces, and cross-plate attached


Here is a closeup showing the attachment of the braces and the rotor plates.

Completed Corner, Outside View

Next, attach the cross-braces between the two pairs of legs Now you have the entire tower together. If you tried tightening all the hardware as you built the tower, you might now have a situation like mine shown below, where you can not possibly align the holes to attach the thrust-bearing plate.

Top Plate holes do not align with the top of the four legs.

Once everything is loose enough, install the thrust bearing plates, then tighten all the hardware starting from the top. The top plate should align nicely like this:


Now attach the feet on the bottom and your tower is ready to mount on the roof. Here is a shot of the completed 4.5 foot RT-424 tower. Good luck.




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