Best antenna for RTL2832U SDR

[debojitacharjee]

I need to know which type of antenna is best for scanning 3 MHz to 3 GHz signals using a RTL2832U SDR?

What is the difference between using a telescopic and a discone antenna? Which is better?

 

[MELERIX]

the one that fits your requirements in specifications

 

[dlwtrunked]

Which will be none as no antenna is a good antenna for that range. Change "antenna" to antennas" and then one can get good answers. But to start, a discone for 100-1000 MHz and a wire (~40 ft or more) for 30 MHz and below. Each will go somewhat usable beyond those ranges. Then depending on you interests, one can go for more antennas.

 

[debojitacharjee]

I want to know whether a loop antenna can only be used to receive the medium wave spectrum (300kHz-3MHz) or can also be used for shortwave of AM reception and FM broadcast?

If MW and SW are both AM then why MW required a loop antenna but SW doesn't?

 

[TAC4]

It all has to do with wave lengths. The lower the band the longer
the antenna. The small ferrite coil found in AM pocket radios is
open to the air at one end, it just looks connected on paper because it is
connected to the tunning capacitor in parallel. No loop antenna
can do all the bands. That's why you see a lot of listeners have
antenna farms to have the best antenna for each main band.

The MW band in Canada is (520-1710) Khz the SW band is around
(1.8-30) Mhz. There are magnetic active loop antennas that can do both off these bands.But with the high inflation they are way over priced. DX Engineering DXE-RF-PRO-1B DX Engineering RF-PRO-1B® Active Magnetic Loop Antennas | DX Engineering

You can also use wire shortwave loop antennas. But you need a lot of room. To get down to 3 mhz you would need around 335 feet of wire shaped like a triangle "delta loop". A better approach
is what bands do you listen to and we can get you a better solution for antennas ?

 

[W8WCA]

To add to that "AM" and FM are types of Modulation used in Transmitting Signals

AM = Amplitude Modulation
FM = Frequency Modulation

AM is not limited to use on Just MW Band and FM is not limited to the FM Broadcast Band.

 

[ka3jjz]

'Overpriced' is a bit subjective - you get what you pay for. There are MANY designs that can cover both MW and HF. The small amplified loops - like the ones Wellbrook used to sell - have nothing to do with having a longer antenna. In fact, many loop designs use a small loop and an amplifier to overcome the design losses.

We have a ton of loop information in our wiki; the MLA30+ is quite cheap but very popular, as there are many folks out there who are experimenting with it trying to make it better. If you are looking for designs for both ranges, look here....

Loops - The RadioReference Wiki

wiki.radioreference.com

Higher up in the price scale are the W6LVP loops. If you want a MFJ loop, get them while you can, as they have ceased production but are continuing to sell their in-house stock. The Pixel and AOR are examples of being 'overpriced' (in my not-so-humble opinion)

Mike

 

[debojitacharjee]

It all has to do with wave lengths. The lower the band the longer
the antenna. The small ferrite coil found in AM pocket radios is
open to the air at one end, it just looks connected on paper because it is
connected to the tunning capacitor in parallel. No loop antenna
can do all the bands. That's why you see a lot of listeners have
antenna farms to have the best antenna for each main band.

The MW band in Canada is (520-1710) Khz the SW band is around
(1.8-30) Mhz. There are magnetic active loop antennas that can do both off these bands.But with the high inflation they are way over priced. DX Engineering DXE-RF-PRO-1B DX Engineering RF-PRO-1B® Active Magnetic Loop Antennas | DX Engineering

You can also use wire shortwave loop antennas. But you need a lot of room. To get down to 3 mhz you would need around 335 feet of wire shaped like a triangle "delta loop". A better approach
is what bands do you listen to and we can get you a better solution for antennas ?

Thank you for all the details. So, as per the formula (300/frequency = wavelength), if I need to build a whip antenna to receive frequency range of 525–1705 kHz, I will need a antenna of a size that can be determined by doing the math below.

525+1705 = 2230/2 = 1115 kHz = 1.11 MHz (focal point of MW range)

300/1.11 = 270 m

So, does that mean that I will need a loop antenna of 270m diameter or a loop of any diameter with a wire of 270m length to receive the AM broadcast?

 

[TAC4]

Here is great link that will show all the wire antenna configurations and how long each wire run is and when you input your data do like you said, for the middle of the band. Wire Antenna Calculator

So it looks like you are interested in the MW band. A couple
of questions.

What radio or receiver are you using ?
Do you want to DX at night for MW stations ?
Or do you want to just listen MW programs during the day?

 

[popnokick]

Thank you for all the details. So, as per the formula (300/frequency = wavelength), if I need to build a whip antenna to receive frequency range of 525–1705 kHz, I will need a antenna of a size that can be determined by doing the math below.

525+1705 = 2230/2 = 1115 kHz = 1.11 MHz (focal point of MW range)

300/1.11 = 270 m

So, does that mean that I will need a loop antenna of 270m diameter or a loop of any diameter with a wire of 270m length to receive the AM broadcast?

Loop antennas behave differently than straight-line wire antennas... and use different construction formulas and tuning methods. To get more details it is best to read up on Loops in the RadioReference Wiki dedicated to all things "Loops" -
Loops - The RadioReference Wiki

 

[Blackswan73]

The ML30 loop antenna that has been mentioned will cover medium wave all the way into the SW spectrum. You also might want to do a google search a”broomstick” antenna. Normally designed for HF, it can be adapted to MW as well. It is basically what you are describing in your original post, but on a larger scale. Think of it as a loopstick antenna on steroids.

B.S.

 

[debojitacharjee]

Here is great link that will show all the wire antenna configurations and how long each wire run is and when you input your data do like you said, for the middle of the band. Wire Antenna Calculator

So it looks like you are interested in the MW band. A couple
of questions.

What radio or receiver are you using ?
Do you want to DX at night for MW stations ?
Or do you want to just listen MW programs during the day?

Yes, I need to use it for Dxing but will it work with SW bands too?

 

[debojitacharjee]

Here is great link that will show all the wire antenna configurations and how long each wire run is and when you input your data do like you said, for the middle of the band. Wire Antenna Calculator

So it looks like you are interested in the MW band. A couple
of questions.

What radio or receiver are you using ?
Do you want to DX at night for MW stations ?
Or do you want to just listen MW programs during the day?

I got the link and read the details.

So, one side of a quad loop antenna is measured by the formula 1/4 * frequency?

 

[dkcorlfla]

Don't think you are going to get 3Ghz on that unit. I believe the highest it can go is about 1.7 Ghz

While it can do lower frequencies by using direct sampling you might be better off using it in the range of 50Mhz to about 1Ghz.

Maybe start with a discone and if you want to listen to the lower frequencies consider a SDRplay as they have much better filters for the lower stuff. As stated previously a long wire would be good for the lower frequencies.

 

[PDXh0b0]

I have 14 different antennas outside for sdr
Tram 1410
Tram 1411
1/4 wave gp tuned to 402 mhz
1/4 wave gp tuned to 433 mhz
1/4 wave gp tuned to 915 mhz
1/4 wave gp tuned to 1090 mhz
1/4 wave gp with reflector for satcom
Patch antenna
Qfh tune to 137.5 mhz
V-dipole tuned to 137.5 mhz
J-pole tuned to 154 mhz
Ofc dipole
Hf dipole
K-180wla loop

Discones are great to find what you want to listen too, then you build an antenna to target your interest 😉

If you want to go above the sdr frequency range you'll need an down converter & appropriate antenna

 

[TAC4]

Based on that info I would go with a MLA30+ and experiment
with that to see if you like the hobby assuming you are new
to the hobby. These metal ring style loop antennas are directional and you can null out strong MW stations and even annoying
noise in your neighborhood which can be a god send.

Copper wire loops are a lot of work, a lot of wire and a lot area
to put up so I don't think they are worth it. Magnetic loop
antennas are the way to go if you are into loops.

For me I just clip 50' of wire that is in my attic to the telescope
antenna of the radio and DX shortwave stations all the over world 🌎 For MW DX I just use the built in ferrite bar antenna and rotate
the radio for the best reception, which results in getting MW
DX from all over the USA 🇺🇸 at night when long range
skip happens in the MW band.

You can make the antennas in this hobby as simple or complicated as you want it's up to you.

 

[ka3jjz]

Copper wire loops need not take up a lot of area; that is simply not true. How about a plastic milk crate as the form?

How to build a Milk Crate AM Broadcast Loop Antenna

Many thanks to SWLing Post contributor, James Townley, who shares the following guest post originally posted on his Shortwave/Medium Wave blog: AM Broadcast Loop Antenna by James Townley Several ye…

swling.com

Mike

 

[debojitacharjee]

I have 14 different antennas outside for sdr
Tram 1410
Tram 1411
1/4 wave gp tuned to 402 mhz
1/4 wave gp tuned to 433 mhz
1/4 wave gp tuned to 915 mhz
1/4 wave gp tuned to 1090 mhz
1/4 wave gp with reflector for satcom
Patch antenna
Qfh tune to 137.5 mhz
V-dipole tuned to 137.5 mhz
J-pole tuned to 154 mhz
Ofc dipole
Hf dipole
K-180wla loop

Discones are great to find what you want to listen too, then you build an antenna to target your interest 😉

If you want to go above the sdr frequency range you'll need an down converter & appropriate antenna

There are two types of radio signals---AM and FM. So, to catch both of them, is discone antenna going to do the job or I have to use a loop antenna and a dipole antenna separately? If I connect both loop antenna and a dipole antenna in parallel then are they going to work at the same time?

 

[debojitacharjee]

Based on that info I would go with a MLA30+ and experiment
with that to see if you like the hobby assuming you are new
to the hobby. These metal ring style loop antennas are directional and you can null out strong MW stations and even annoying
noise in your neighborhood which can be a god send.

Copper wire loops are a lot of work, a lot of wire and a lot area
to put up so I don't think they are worth it. Magnetic loop
antennas are the way to go if you are into loops.

For me I just clip 50' of wire that is in my attic to the telescope
antenna of the radio and DX shortwave stations all the over world 🌎 For MW DX I just use the built in ferrite bar antenna and rotate
the radio for the best reception, which results in getting MW
DX from all over the USA 🇺🇸 at night when long range
skip happens in the MW band.

You can make the antennas in this hobby as simple or complicated as you want it's up to you.

That's quite an expensive antenna. Why should I buy it if I can build one?

Do you know the formula to build a loop antenna?

 

[TAC4]

Ok I will take the bait Mike lol For a full wave copper wire
loop antenna at 3 mhz your milk crate would have to be 67 feet squared
lol Interesting enough you could fit 22 normal size milk crates
In that one large milk crate which would make one hell
of a loop antenna array.

That said Mike if you are going use that many crates would
it not be easier just to make a milk crate tower and put a MLA30+
on top of that ? Just sayin, wink wink