a quick queation about atennas

Discuss commercial and home made antennas.
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mactuan12
Posts: 1
Joined: Thu Jan 09, 2020 5:40 am

a quick queation about atennas

Post by mactuan12 » Thu Jan 09, 2020 5:45 am

I just bought my first RTL-SDR. I'm super excited to start playing with it. The bundle I bought came with 3 antennas and I bought an extra one for ADS-B. So, in total I have one 433 MHz antenna, one "UHF" antenna, one telescopic antenna, and one 1090 MHz antenna. First, I don't know the specs of the telescopic antenna; but, if it was possible to set the antenna to 1/2 or 1/4 wavelength, which is better? Second, what is a good universal antenna length? To clarify: some SDRs I've seen come with a decent all around antenna, how tall would that be? Finally, what angle should the antenna be set at (e.g. perpendicular to the horizon, parallel to the ground, or somewhere in the middle)?

EDIT: Found out that the supplied telescopic antenna is about 15-60 cm, so just over 1/2 a wavelength for my intended use, but I'd still be interested to know. Also, I though of another question! From what I've seen, a popular place to put the magnetic base is a metal pan. Would a filing cabinet work better, worse, or the same?

HighSNR
Posts: 47
Joined: Mon Sep 18, 2017 8:14 am

Re: a quick queation about atennas

Post by HighSNR » Thu Jan 09, 2020 6:35 am

Hi

It's difficult to know the exact length to tune a telescopic antenna. The cable and ground plane play a big part. 1/4 wavelength is a good start point. Unless you have a VNA, you can just tweak for optimal reception. It all depends on how critical it is to extract those last few dBs of sensitivity.

Vertical is often the correct polarization, but it should be set to match whatever the incoming signal is.

If you want something that is more guaranteed to work at a range of frequencies you can use ultrawide band antennas such as Spirals, Vivaldi's or Discone's. I happen to know someone who sells such items on Tindie ;)

Username
Posts: 533
Joined: Sun Oct 09, 2016 7:27 am

Re: a quick queation about atennas

Post by Username » Fri Jan 10, 2020 5:33 pm

Well:
a) where are you from?
b) what band are you want to tune in?

I will behonnest the Telesopic Antenna is good for Travel when you want tune into local Radio and you might understand the foreign Languae for more.
For a Stationary Setup I would buy even a good cheap Antenna.

If you are from Europe: https://www.delock.de/produkte/G_1468_Antennen.html

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