Apr 292015
 

In real life, be it competitions or history (Desert One, Grenada, Panama, Afghanistan, Yemen, etc.) the USA is not even in the top 10.  And the only reason why so many Americans believe in the superiority of their forces, is simple crass ignorance.

Amen.

Read more.

Apr 022015
 

This antenna was posted in 2012 on FPVLAB, obviously never made it into the blog…solved. 😉

Just in case someone needs a simple and easy to build ground station antenna, usable with any 433MHz TX, here is a solution:

Beer-CanTenna measurement setup:
BeerCanTenna_Measure
Return loss at 433MHz:
BeerCanTenna_Return_Loss
Inside the can:
BeerCanTenna_Inside
On a tripod, extended to ~3m height:
BeerCanTenna_Tripod

What you need:
1x Beer can, height 170mm, outer diameter 66mm, top opening diameter 52mm
1x Steel welding rod, 500mm length, diameter 1.5mm
1x BNC or SMA panel mount socket with front side nut

How to build:
– First, enjoy the beer, thats a mandatory step. 😉
– Remove the top cover of the can. In a way, that you keep the outer folded ring.
Folded_Ring
-Drill a hole in the bottom center to insert the BNC/SMA socket.
– Solder the welding rod to the BNC/SMA center contact.
– Measure the length of the rod including the center contact and cut the overall length to 490mm.
– Insert the socket through the bottom hole and fix with the nut.
– Cover the top opening with some non-conductive material. I used some EPS foam.
Top_cover
– That’s all.

I made a extension pipe with a BNC socket on one end and some tripod adapter on the other. This way I can raise the antenna up to 3m on the tripod.
Extention Ext_Socket Ext_Cable
The antenna connects with a 5m BNC cable to the transmitter.

I have tested the antenna during my 11km flight with excellent results.
BeerCanTenna_RSSI

A fellow pilot uses a second antenna with 433MHz 3DR radio modes to control his APM2.5 plane. He was 3km out already then chickened.


Note, a different size beer can may require a different length of the welding rod.