Antenna Coil placement.

Posted: 4/30/2012 2:04:26 AM

From: US

Joined: 8/17/2011

In an attempt to increase the distance between the volume and pitch antennas I am currently working on mounting my pitch antenna on a rod that will extend from the main box, kind of like an etherwave pro. I read that it is best to place the antenna coils near the antenna so that the long wire leading from the antenna to the circuitry isn't post-coil and therefore too sensitive. Before I do too much I wanted to ask about the importance of antenna coil orientation.

Does it matter if the coils are oriented such that they produce their magnetic fields in the same direction or is it fine to have them wired in a snake-like shape so that the magnetic fields are opposite of eachother (I would think that this might reduce overall inductance)?

I was also wondering if it mattered whether or not the coils were aligned such that their magnetic field went along the length of the antenna. i was considering perhaps just sliding the coils inside my antenna since it is hollow.


thanks for your time.

Posted: 4/30/2012 3:58:46 PM

From: Northern NJ, USA

Joined: 2/17/2012

If your linearizing coils are not air core then orientation probably doesn't matter much as most of the flux is concentrated in the ferrous core material.

Inside the antenna is an option, though I'm not sure I'd put them inside of a metal antenna due to capacitive loading / interaction between the outside of the coil and the inside of the antenna. 

My current AFE has the coils inside the antenna, but the antenna is plastic (3/8" PEX) with an outer layer of aluminum foil tape, heat shrink tubing over the whole thing, and a vinyl 3/8" automotive vacuum cap on the end.  I kept the aluminum tape away from the lower section that contains the coils.  UHF connectors work great for this by the way, nice mechanical and electrical connection, way better than plumbing, and it looks sharp too, like a rubber ducky antenna.

You must be logged in to post a reply. Please log in or register for a new account.