Trial Run Results for Three Types of Whip Antennas

[Mephisto]

In addition to cutting the whip to optimum length, there is another step for improvement: Place the mag-mount antenna over a metallic surface.

Followed this hint already as I put the antenna (which is a soldered piece of power wire) on a metal flowerpot. Seems to work properly. Getting nearly 80-85% of my maximum reach already. The antenna is in the attic.
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[abcd567]

Thank you for your work. I tried today to increase my range and it worked out for me. Before cutting I got avg 59nm of range. Now its over 100nm.

In addition to cutting the whip to optimum length, there is another step for improvement: Place the mag-mount antenna over a metallic surface.

The 1 inch (25 mm) dia magnetic base does not provide sufficient ground plane. By placing it over a metallic surface, it gets larger ground plane and it's performance further improves.

An additional advantage of food-can is that as most of the food-cans are made of iron/steel, the magnet in base of the whip will cling to it, and keep antenna in stable vertical position.

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[Mephisto]

Thank you for your work. I tried today to increase my range and it worked out for me. Before cutting I got avg 59nm of range. Now its over 100nm.

[scott1304]

It's a normal dvbt+ dongle

[abcd567]

Hello, sorry i mean what kind of adapter you have to trace planes.

flightradar blue, yellow, or a normal dvb-t dongle.

This is NOT called adaptor. It is called RECEIVER.

[AlejandroM]

Hello, sorry i mean what kind of adapter you have to trace planes.

flightradar blue, yellow, or a normal dvb-t dongle.

[scott1304]

which adapter do you have? for me cantenna is the best option even trying another antennas.

I've got a mcx to F-Type adapter, cut a small amount from my whip and the range went from 59 down to 40nm, putting a normal sized whip back on increased it to 60nm. want to try and get the best range I can.

[abcd567]

3 EASY ANTENNAS FOR BEGINNERS

[AlejandroM]

which adapter do you have? for me cantenna is the best option even trying another antennas.

[scott1304]

I tried the cantenna but signal dropped after 10 minutes or so. Can only pick up 59nm using standard antenna, this is such an interesting topic so will be giving it a try later today and see what the effects are.

[AlejandroM]

wow, this is a really interesting topic.

i will keep working with the cantenna, i had the whiped antenna but is not working as desired, maybe because it doesnt have a filter on that location ( possibly)

i found a coffee can, but is 6 inches diameter, can work as cantenna? i will install a new raspberry just to test antennas.

[wiedehopf]

It won't have good performance.

You can look up antenna impedance but it's a very complicated topic.
Let's just say, monopole antennas with groundplane are gonna be best at 1/4 wavelength.

Or you can build a dipole antenna (the half-wave dipole antenna is most common): https://en.wikipedia.org/wiki/Dipole...lf-wave_dipole

Note that using other than half-wave dipole antennas means you need impedance matching.

[AlejandroM]

i have a question on this.

If 1/2 wavelenght for 1090 MHz is 138 mm and I want my antenna to be 1/4 weavelenght (=69 mm)

what happen if an antenna is working at 1/2 wavelenght? it will work?

[majo]

@abcd567:
Thank you for this quick and competent reply!
Now I`m confident and can start cutting...

[abcd567]

@majo:
In antennas, there is a phenomenon called "end effect". Due to this effect the physical length of antenna is slightly shorter than its electrical length by about 97% to 98%. This is mainly due to radio waves travelling slower in metallic wire than in the air, and also due to capacitance effect at the ends of the antenna.

Taking an average figure of 97.5%, the physical length of full wave wire is 275x0.975=268mm, and 1/4 wavelength wire is physically 1/4x268=67mm