Saturday, January 29, 2011

Antenna experiments - coffee caps

First let me tell you I am not affiliated in any way with the coffee capsules brand reported here (Nespresso). Neither I like closed format or standards.... from what I can tell this experiment could had been realized with the use of any other brand of coffee (Nexpresso is a proprietary format....whatever!)!

Basically I wanted to see the influence of capacitive elements in antenna impedance values. The antenna is just a vertical element of around 50cm (1/4 wave on 144Mhz band) and no ground plane was made except that the meter body acts as such (more or less).
Here the 2 versions with and without the capsules:


Capsules were randomly distribute over the element and are made of aluminum (were empty since I drink the coffee)....

Now the obtained values with the MFJ analyzer:



...so the "scientific" fact is that coffee capsules can lower your antenna SWR.

Have fun!

p.s. I promises one of this days I will make a more mathematical analysis on this subject but for now this is amateur radio...

2 comments:

James said...

I wonder if the measurements wouldn't be more accurate on something like this swr analyzer over the MFJ.

Ricardo - CT2GQV said...

Hello James,

I really don't know! :)

73 de Ricardo - CT2GQV