Soldering an Antenna and the variations of radio range .

Other Hardware General Electronics
1

i have this module :

i think the main range without an Antenna soldered is below a meter (can't recall exactly) .

and as the image recommends . i should solder an Antenna .
though due to my limited experience with these modules . i don't even know what kind of Antenna it is .

so what kind of "Antenna" should i solder to maximize the range ? thank you

2

Have a look at What 433Mhz antenna should I get? - Networking, Protocols, and Devices - Arduino Forum

You know that there is a search function for the forum?

Searching '433mhz antenna' gives 896 hits. (I posted one of them above)

3

Whandall:
Have a look at What 433Mhz antenna should I get? - Networking, Protocols, and Devices - Arduino Forum

You know that there is a search function for the forum?

Searching '433mhz antenna' gives 896 hits. (I posted one of them above)

Ok .

i have some broken RC w-controllers .
can i use the intennas that come with those ? i have many broken antennas . will any random one work ? or is it better to just use a wire ?

4

A wire of the appropriate length is usually best.

Antennas from other equipment will have been built for different frequencies and will not be as good as an antenna of the right length.

5

MorganS:
A wire of the appropriate length is usually best.

Antennas from other equipment will have been built for different frequencies and will not be as good as an antenna of the right length.

thank you Morgan . now what do you mean '"the right length"" like what if i use a wire that is much longer than the ""right length"" will that damage the transmission ? or improve it even more

6

will that damage the transmission

No.

Too long is the same as too short, the range is reduced.

7

Grumpy_Mike:
No.

Too long is the same as too short, the range is reduced.

thank you very much Mike . should i coil the wire or leave it straight ?
and should i pick a thick copper wire ? or a normal one ? and will that make a difference ? thank you

8

Leave it straight, the thicker the wire the broader the bandwidth, but here it makes little difference.

9

tbh, I had those exact tx/rx and no matter what I tried, even posting on here, I wasn't able to get more than 10m of range of them.

I switched to superheterodyne tx and rx and now get >30m range no problem through multiple walls.

I didn't try the dipole antenna, but 38cm was just too much antenna for my application

10

Wonder if you can still get relatively cheap VSWR meters like the Radio Shack model I once used for 10 & 15 meter ham antenna work? Seems like it would be a big help here.

11

outsider:
Wonder if you can still get relatively cheap VSWR meters like the Radio Shack model I once used for 10 & 15 meter ham antenna work? Seems like it would be a big help here.

Not really, unless you can attach a proper coax connector to the module. Even then, your VSWR will change immediately after you remove the VSWR meter. :slight_smile: Also, the cheap ones don't go over 50Mhz.

@amine2, I could tell you the proper length, but I'm in a room full of chattering people who won't leave me alone. It's 1/4 wavelength at 433Mhz. It's about time you learned to calculate that.

12

It is alright calculating the theoretical length, but you need to include a velocity factor for the wire, and that screws things up as that is not precise. Best start off with the calculated length plus 10% and then snip off very small pieces and measure the distance of communications.
Make a note and plot a graph of your results.

Your wire will be too short when you have found the peak but then you know how long to make it, so make another.

13

After you've tuned your antenna that way, start all over again when you've moved anything conductive in the vicinity of the transmitter or receiver. Or when you have moved the unit itself. Because a 1/4 wave antenna needs a counterpoise to work, and with this type of radio, the counterpoise is the Arduino itself, and any wires that are connected to it. If those move, all your careful work will be mostly in vain. That's why I just leave it at saying 1/4 wave. I know about velocity factor. It's important for a "real" antenna, but a "real" antenna has a genuine counterpoise, and provisions for isolation from the radio. If memory serves, you can get very close to the VF for bare wire by making it about 5% shorter.

However, I do usually put a pin on the antenna connector, so I can fool around and get the best results as Grumpy Mike is suggesting. If an antenna gets too short, or I have an idea to try, I don't have to mess with the board.