Electronics > RF, Microwave, Ham Radio

Quantity chickens sacrificed for 433MHz antenna?

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In case the subject line escapes you, it is a reference to voodoo... Because that's exactly what antennas seem like to me.  Maybe I should be posting this in the Beginner forum? 

For me personally, learning happens by first possessing some general concept of the thing being learned.  Then, slowly heaping on technical aspects.  Without a modest grasp of the concept, the technical aspect might as well be in a foreign language.  My eyes glaze over, my pulse quickens and beads of perspiration will form on my neck just before I fall asleep. 

My first foray into RF is experimenting with the cheap 433MHz rx/tx modules.  That's is where I'm at.  I've attached 17mm copper wires to the antenna hole, wired them up to a breadboard and failed to achieve even my low expectation of the results.

There's tons of info on antennas on the net, but most of it is technical.  It doesn't help that many of the tutorials (arduino) about these modules, lacking adequate datasheets, are simply recipes for how to make them work, though not particularly well.  Further, all of the ones I've read are generally by people with no real knowledge of RF.  Many are written by people whose ambition is to make something work, not to actually learn.  I'm the latter.

So, for now, I'm just hoping you know of some nice "Antennae for Idiot" sources that you like.  I've found some for "dummies" but alas, I guess I'm not that smart.

Don't know what floats your boat, but the ARRL publications generally start slow and then build.

But more fundamentally, you appear to be aiming for a 1/4 wave antenna.  That should be about 17 centimeters long.  If your post accurately states that you used 17 millimeters you would expect poor performance.

Your understanding of the OP is correct.  I got that number from numerous sites regarding this particular tx/rx pair.  Without an understanding of antenna theory, I am relegated to recipe following myself.  The current antenna configuration will only extend 1 or 2 meters, mostly a product of the antenna I suspect.  The software however, is also primitive and partly to blame for poor communication.  There isn't much filtering of noise.

Hi Chipwitch, what rx/trx pair are you using ?

The length of an antenna is related to the wave length of the signal.

The wave length is the speed of the signal divided by the frequency.

In the wire the speed is about 95% of the speed of light in a vacuum (3*10^8 m/s) or about 285*10^6 m/s

So the wave length of 433 MHz is 0.658m.  1/4 wave length is 0.164m or 16.4 cm.


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