[TowerTalk] Hy-Gain HG70HD thrust bearing

[Ken Alker]

Hi,

I recently acquired a Hy-Gain HG70HD tower.  I hired a crane operator to 
lift the mast/antenna assembly off the tower and then had the tower lifted 
out of the back yard and placed horizontally on a boat trailer to haul it 
away.

When I got home, I removed a "collar" from the mast that appears to be what 
might sit on top of a thrust bearing (or, perhaps, *is* the "top" of the 
thrust bearing assembly).  Here is a picture:

http://www.alker.net/albums/ham-tower-thrust-bearing/IMG_6986.sized.jpg

This collar rested in a "female" circular mating piece that is bolted to a 
plate on the very top of the tower.  See following pictures:

http://www.alker.net/albums/ham-tower-thrust-bearing/IMG_6984.sized.jpg
http://www.alker.net/albums/ham-tower-thrust-bearing/IMG_6985.sized.jpg

I am assuming there was some kind of bearing "pack" sitting in between the 
collar and the mating surface on the top of the tower that was stuck to the 
bottom of the collar and fell off when the mast was lifted off the tower, 
or it stuck to the mating surface on the top of the tower and fell off when 
we tilted the tower over (or when I drove off).

That said, I'm not totally convinced there was ANY type of bearing between 
these two items.  Maybe they are meant to be lubricated and swivel against 
each other?  I don't think so, but I have no idea, as the manual I found 
doesn't show any pictures of the optional thrust bearing assembly.  There 
is enough space between where the collar sits on the top of the tower, and 
the inner "shelf" mating surface for some type of bearing assembly (I'm 
thinking of the circular exposed, but captured, ball bearings that I found 
in my Schwinn bicycle hub when I disassembled it as a child in the 1970's).

Can someone please enlighten me?  I'd really like to see some pictures!  I 
can't find anything via Google.

If there is a bearing that gets sandwiched between these pieces, does 
anyone know where I can get one?

Thanks!
Ken, KA6KEN