[Lowfer] helix house?

[Bill Ashlock]

Eric,

>Does the loading coil radiate?

This is close to a loop antenna question so I'll take it. The coil doesn't 
radiate too much because of its small size. IE: the radiation resistance 
would compute to be VERY small. BUT there is a strong AC magnetic field 
surrounding the coil that needs to be kept away from metallic objects of any 
size or the coil Q will be destroyed.

>Should it be exposed (in terms of >RF)?  Or can I put it inside my >steel 
>building along with the amp?

You could do this but the problem is how do you transport the output of the 
coil to the antenna without picking up a lot of stray capacity where you fed 
it through the roof? This added capacity will introduce additional losses 
because additional current will flow through the coil and IsqRac losses will 
increase. Would suggest a feed-through of maybe 8" diameter in the roof to 
keep this capacity down. Keep the distance from the coil to roof as short as 
possible (consistent with not being so close that the Q is effected) to keep 
the inside radiation of the lead-in to a minimum.

Bill




_________________________________________________________________
The new MSN 8: smart spam protection and 2 months FREE*  
http://join.msn.com/?page=features/junkmail