AB-15 Antenna Sections problem

[Mainsail]

Finally got all the parts together in one place and ready for install.

Bored a big hole in a cover plate I had laying around- made a lot of noise and mess but it's done.

Then disaster.

Trying to screw the three sections together I managed to destroy the center section. The threads are not engaging right. I had some vice grips taped up good to prevent scratching, but they just wouldn't mate. Tighter and tighter with the pliers until it bent and broke through the section.

Is there a trick to this? All three sections have paint damage and the center one has a hole now.

 

[tennmogger]

Assuming you have the MS116, MS117, MS 118 series sections that are normally with the AB15, something is definitely wrong with your threads. These should screw together by hand, and never more torque than that. These sections do sometimes stick together after a long time but that is the opposite problem.

Were the sections flattened or otherwise deformed? Rusty?

Can you verify the type sections you have? Sure sounds like you have a defunct set now.

For future need, here's a clamping method that works without damaging the sections. Use a wood block, like 3 inch long 2x2, and drill a hole down the center 'the long dimension' the same diameter as the antenna section. Then saw the block down the middle of the bored hole. Now the diameter of the hole is reduced by that thickness in one direction. Wrap the two halves around the antenna section and clamp in vise. You can't crush the sections.

If no vise is available, or if two clamps are needed, a C clamp works as a handle.

 

[SCSG-G4]

And if your MS sections are dirty or rusted, use Naval Jelly to clean them up (inside and out) and a wire brush on the outside and a correctly sized bore brush for the inside, then follow with plenty of hot water to flush out the Naval Jelly. Allow to dry and use copper Never-Sieze applied liberally on the threads. As Bob said, hand tight is enough - don't force it!

 

[Mainsail]

That's the thing, they look great- or did look great. Not out of round, dented, dirty, or corroded. I'm starting to think they are not really MS-116 thru 118 at all.

I ordered two new lower sections so we'll see how it goes.

Thanks much for the assistance! I will not force the new ones when they come in.

 

[papakb]

Something to be aware of when working with these mast sections is that they're made of copper plated steel and if left together untreated they will eventually rust "freeze" and at that point they're basically scrap tubing. When assembling your antenna always use some type of grease between the sections. Whether it's gear lube or electrical anti-oxidant grease or high tech silicon lube you always want a film of it where the sections screw together.

Another trick to keep your antenna healthy is to lube the bottom section where it screws into the AB-15 or an AB-558. I always install a distributor cap rubber nipple over the lowest section to keep water that collects on the antenna from running down into the base and cover the top of the base when the mast sections are removed.

Simple things that will keep your antenna in good shape for years.

 

[tcruwithme]

TM 11-5820-401-10-1 says that if any of your MS-116A, MS-117A, or MS-118A antenna sections break, you can replace all three of those antenna elements with one AT-1095/VRC. I suggest that in case you can't get those sections to work correctly.