Choosing an SDR Receiver for Airline Channels, Electronics, and Mobile Use

I want to buy a USB SDR receiver.
I see that there are several most popular models:
1. The cheapest, usually black, the size of a pen drive with the inscription DVB+DAB+FM. The set includes a small antenna and remote control. From $10.
2. Blue in a square (from the top) housing with the inscription "Android", antenna and remote control.
3. In a cubic greenish box marked "Newgen RTL2832 SDR".
4. Similar, in white, with the words "RTL-SDR.COM".
5. Black "Foxway", with two antenna connectors: 100kHz-30MHz and 25MHz-1.7GHz. From $35.

...and probably others (but too expensive).

Could I ask for advice on which one to buy?

I`d like:
1. Listen to airline channels (approx. 122 MHz AM).
2. Use when building and testing electronic circuits (amateur).
2. Ability to work with a smartphone (and not just a PC or laptop).
3. Worked on Linux and Windows.
4. Wide bandwidth - also long waves.
5. Good sensitivity.
6. Good additional equipment (e.g. antennas).

Greetings Marcin

Read/ask here: https://www.elektroda.pl/rtvforum/topic2353101.html

Of the cheapest ones, blue is recommended, but numbers 1, 2 and 3 do not meet your requirements:

Quote:

4. Wide bandwidth - also long waves.

Nos. 4 and 5 probably also receive frequencies below ~24 MHz using the direct sampling method. The simplest and the worst.

Taking into account:

Quote:

2. Use when building and testing electronic circuits (amateur).

You`re no stranger to using a soldering iron, are you? In such a case, I recommend the cheapest blue tuner, plus the AD831 mixer module for $10 from AliExpress and a quartz generator, e.g. 80 MHz - PLN 5 on Allegro. Add an attenuator consisting of 3 resistors and you have a ready upconverter. A much better option for HF bands than direct sampling.

The cheapest blue tuner differs from slightly more expensive ones mainly in accessories. It may have a stable TCXO, aluminum housing (screen + cooling), SMA socket. However, they are still based on the same RTL2832U/R820T2 systems. They have the same sensitivity and will work equally well on a smartphone, Windows and Linux. What about additional equipment? You will choose this individually. After all, an antenna for the HF band will not be different for blue than for black.

I will return to the topic: is the "RTL2832U+R820T2 100KHz-1.7GHz UHF VHF HF RTL.SDR USB Tuner Receiver AM FM Radio" receiver
(e.g. https://www.aliexpress.com/item/32965619493.html) is it really the same device as the cheapest "RTL2832U+R820T2 pendrive" only with the "defective" sampling at lower frequencies described above?

240sx wrote:

I will return to the topic: is the "RTL2832U+R820T2 100KHz-1.7GHz UHF VHF HF RTL.SDR USB Tuner Receiver AM FM Radio" receiver
(e.g. https://www.aliexpress.com/item/32965619493.html is actually the same device as the cheapest "RTL2832U+R820T2 pendrive" only with the "deficient" sampling at lower frequencies described above?

Exactly. If you scroll down, in the customer reviews section you will find photos of what it looks like inside. An ordinary tuner glued into a larger board with direct sampling.

PS Remove the closing bracket immediately after the link, because you can`t enter by simply clicking.

Thank you for the information.

Does this mean that the available "assembly kits" are exactly what you just mentioned? Pendrive, mixer, silencer:
https://www.aliexpress.com/item/4000171946465.html

From devices that, according to descriptions allow reception from 100kHz there is also: https://www.aliexpress.com/item/32621388951.html
Does anyone have it or can you tell from the description whether it is better/worse than those described earlier?

Both devices are still only direct sampling. Using a mixer with a generator, you can build a real converter plugged in between the antenna and the RTL-SDR antenna connector.

It`s decided: I`m buying the "cheapest" SDR receiver in the form of a pendrive.
Could you please tell me where to find the exact implementation of the device you described?

240sx wrote:

It`s decided: I`m buying the "cheapest" SDR receiver in the form of a pendrive.

I recommend the most popular "blue".

240sx wrote:

Could you please tell me where to find the exact implementation of the device you described?

When I understood that the converter is a simple combination of a mixer and a generator, and not any complicated device, I built something like this myself:

20181005_2..732.jpg Download (418.73 kB)

Several elements connected together, a great description is probably not necessary. If you need any details, just ask.

You can omit the low-pass filter at first and build it later if needed. In quiet rural areas it may be unnecessary, but in the city, near strong transmitters.

Hello, I am also planning to start my adventure with SDR. I`m currently using a Baofeng dual band. but I want to expand the possibilities of listening on the air. My question to Sumar is "I live in the city, in blocks of flats around. So I have a lot of interference. Does the above description of the topic only work on kf? I would like to build something with my own efforts, some filters for this pendrive.

The photo above shows the filter already closed in the housing. Here is an earlier photo where you can see what`s inside. It`s an ordinary low-pass filter with SMD elements, made according to a pattern. At the moment I don`t remember what the values of the elements are, but it was made at about 30 MHz. Currently, I have changed the location, I have no way to hang the HF antenna here and the topic has been forgotten for a while. However, I can say that the filter worked properly - it did not worsen the desired signal, but it definitely cut out regular FM radio stations. The construction of such a receive-only filter is simple, because there is no need to wind the coils with thick wire, you can only use ready-made SMD elements, because it will not transmit any power.

Well, it`s a pity you don`t remember. Some kind of projection would be useful. Because it`s not very visible in the photos. And ready-made filters exceed the price of the device. I already have the monitor. Connect the HP terminal to this. And listen. To start with, which SDR modem would you recommend, working from 100khz to 2GHz? If I like it, I`m willing to play with the antennas.

You can look at the diagrams in google images under sdr upcoverter. Most of them have a low-pass filter on the input. To start with, I recommend the blue tuner + upconverter. If you are not afraid of a soldering iron, I recommend the passive one with the ADE-1 mixer. As for the terminal, it may be weak. I tried to run RTL-SDR on something like this and it was very sluggish, both on Windows and Linux. However, SDR is resource-intensive (especially spectrum analyzer and waterfall).

I`m not afraid of soldering irons. Overall, he is a DIY enthusiast in his free time I have access to welding machines, soldering irons and lathes. As for the technical specifications of the device, I couldn`t find an answer anywhere as to whether it would be that much of a burden. Maybe the terminal`s parameters weren`t impressive. Which you used. But I will keep looking for answers. And the plan was to buy a 4x1.7 processor with 4GB of RAM.