[TowerTalk] ...Compressed Air Driven Tower

[Ian White GM3SEK]

Jim Lux wrote:
>
>>So every time you lower the mast, it spits out a horrible mess of greasy
>>water. And you don't dare to raise or lower the mast in freezing
>>conditions, for fear of tearing the seals.
>>
>>Because the inside of the mast is always wet, corrosion can make a
>>strip-down very difficult indeed. The ones I've used are a nightmare of
>>tiny parts, including more than a hundred 3/16in screws...  steel
>>screws, corroded into aluminum.
>
>In theory, if they're always pressurized with dry gas, then this 
>shouldn't happen.  There's a little bit of leakage, so the new dry gas 
>tends to flush out the moisture.
>
Maybe I was being too discouraging, but take my experience as a warning: 
don't let them run wet inside! If you're thinking of extended home 
station use, either set yourself up with a permanent gas supply as Jim 
says, or expect a short working life.

>
>>Bottom line is that these masts are great for their intended purpose: a
>>mast that can go up anywhere, for a short time, and then you let it down
>>and move on.  But they require *constant* attention.
>
>Exactly that... constant, regular maintenance (like an older British 
>sports car<grin>).

I'm writing from Abingdon-on-Thames, where the MGs were made. They used 
to push them along the production line by hand, so why should it be any 
different for the owners? :-)

>They're not something you bolt to a trailer and use once a year at FD.
>
Beg to differ there, Jim: occasional use is exactly what they *are* good 
for. It's an essential feature for their intended military or commercial 
application. Both of mine had been stored a long time (one was NOS, the 
other had seen some field use) and they both went up with no problems.

It's no trouble to keep them pressurized for the FD weekend, and if you 
store them correctly (read: dry inside) for the rest of the year, they 
should be fine for next time.


-- 
73 from Ian G/GM3SEK