RTL-SDR - an SDR receiver from a cheap DVB-T tuner on a USB connector

For me, the "blue" RTL2832U program works - searches for stations and everything works as it should, even on a short antenna when I'm outside.

Hmm, I probably have a tuner released, you can ask for help in this topic ?

For me, the signal jumps from 0 to 80, it does not find any stations, and it works fine on SDRTouch.

The blue toy has the R820T2 tuner chip and the LV5TDLX has the FC0013.
By the way, the LV5TDLX tuners are susceptible to damage caused by short circuits. I myself have burned some of them. I recommend mounting the device through an antenna separator. Signal too strong may also be a problem. Sometimes a relay operating nearby can cause these effects.

don_viking wrote:

... By the way, the LV5TDLX tuners are susceptible to damage .... The problem may also be too strong signal ...

I think I already know that, I remember something that I connected it to the cable signal in the past, which could just release it, because there is quite a strong signal ...

Gentlemen, help me install rtl-sdr because my hands are dropping.
The amateur bands do not work for me.
I have such a thing.


I do the installation like this.
1. On the part https://airspy.com/download/ i download this software.

2. I run install-rtlsdr and download ZADIG
3.In Zadig, I install drivers for BULK


In SDRDharp I choose the RTL-SDR (USB) device and ...... everything works but only from about 30-40MHz up.

For example in the amateur band 40m, total silence. And the signal from the antenna is 100% because it works well on the HF radio.


Here you can see that it is possible to receive such low frequencies.

m72 wrote:

... amateur bands do not work for me ...

What kind of KF converter do you have?
Just don't write that you don't have any .

I do not have any
Damn, what else do you need to buy for this?

unless you make a fashion for direct sampling

Click on the gear symbol and switch from Quadrature Sampling to Direct Sampling.

99% of the version shown in the picture will not work, you have to make a hardware mod

without direct sampling, you can work from 24Mhz - you can see a clear signal switching when you exceed this frequency

shadow4601243 wrote:

99% of the version shown in the picture will not work, you have to make a hardware mod

without direct sampling, you can work from 24Mhz - you can see a clear signal switching when you exceed this frequency

It seems wrong - it does not work :)

Ok, what do you need to buy for it to fire below 24MHz?

http://www.radioforeveryone.com/p/the-new-smart-manufacturer-link-can-do.html

shadow4601243 The method of connecting the signal directly to the chip is very dangerous. Any overvoltage (even from static voltage) may damage the system. Separating capacitors will not help much. Significant voltages are induced in unprotected KF antennas, even with distant lightning discharges or strong radio signals.
With such a connection, the tuner should be modified (as previously mentioned by colleagues) in order not to release it.
Of course, one tuner will run for a year or more without protection, and another will fail after a day.
It is up to the user to decide. Actually, the tuners aren't that expensive ... .

There are special versions with this workaround already made.
I have something called "rtl-sdr v3" and it grabs from 500khz, has alu casing (cooling + shielding) and 1ppm accuracy (extra quartz, in the cheapest frequencies they can drift a lot as they heat up).
It is a bit more expensive, but in my opinion it is worth paying extra if someone likes to play scanning.
Remember that with direct sampling we avoid the amplifier, so you need to take care of the external one (unless you have access to a solid antenna).

shadow4601243 wrote:

There are special versions with this workaround already made.
I have something called "rtl-sdr v3" and it grabs from 500kHz, has an alu casing (cooling + shielding) and 1ppm accuracy (extra quartz, in the cheapest frequencies they can drift a lot as they heat up).
It is a bit more expensive, but in my opinion it is worth paying extra if someone likes to play scanning.

I am curious what you think about this SDR, opinions, tests, how it works and receives in the 24 MHz band. Best regards.


260044308_...rev025.jpg Download (16.78 kB)

You see that "v3" on the bottom left? I wrote about it exactly.

I need something more about him. Owners' opinions about how it behaves, noise, etc. Regards.

http://www.radioforeveryone.com/p/review.html

Anyone converting their rtl to direct sampling here? What core do you recommend to buy, size and material, and what gear to use? Apparently the rtl impedance is 3300 ohms ... such a ratio requires "some" turns

Anyone use this V3? Can you buy somewhere?

I recently bought a blue RTL2832U & R820T2 tuner. In general, everything works, only something is weak. I compared it with the Baofeng UV-82, which is also just an ordinary SDR without filters. And yes, Baofeng receives a strong signal clean and clear, while the same signal on the SDR is noisy. A similarly noisy signal on Baofeng on SDR is already incomprehensible.

I enclosed the SDR receiver in an aluminum housing, and I used a ferrite filter for USB power supply (I also tried it on a laptop powered only by a battery).
PPM is properly adjusted, I set RTL AGC, Tuner AGC, RF Gain in all possible ways. There is no way I can achieve the same effect as on Baofeng. Both receivers are connected to an ordinary half-wave dipole on the roof, of course each to a separate one. I live in a quiet, suburban neighborhood with no strong signals nearby.

To sum up: this type is like that, is there anything else you can do?

This type is like that and it won't be better. Like it or not, Baofeng aspires to a radio communication device where it operates on single watts and RTL is a TV receiver adapted to receive stations of several kW.

I suggest making a good preamplifier and connecting it between the USB tuner and the antenna. I have already mentioned such a solution once because I use it myself. In order not to play with the assembly of the preamplifier from scratch, I used the SWA9701 board from the broadband antenna. The only thing I replaced were the transistors and I used them from an old cell phone, they had the symbol "R2p", it was probably BFR93A, and I removed the balun and connected the antenna directly to the output of the balun on the board (ring with a wound cable). In the photo I marked where to connect the antenna. You can still play with matching capacitors and resistors, but the effect was so good that I didn't do it.
Yellow color of the mass
Red main vein


For me it works great, I receive signals that I did not receive before and I do not have to turn on the AGC, and the amplification is around 20.

By the way, I have completed the database of programs for the sdr tuner ready to use in the topic I am promoting below.

Don _ Viking, that's a good idea, I have to try, I have more of these boosters.
Wild
Jard

If someone would like to make a good single-band antenna with a good profit, I recommend this diagram in the picture. I have 3 pieces, one at 1090 MHz, the second at 2 m and the third at 70 cm, all of them work perfectly. The selection of the number of elements must be individually adjusted by everyone, preferably an even number as shown in the drawings, so that the radiator at the top connects to the cable's main conductor. As for the length of the elements, there is a formula for calculating for a given frequency. I would like to add that when making an antenna for 70 cm with a certain number of elements, the antenna also receives good reception at 2 m. I don't remember how many elements it was, but when I added more, the sensitivity dropped drastically on the 2m band.

The driver for HF pickup is modified. No converter needed. Obviously the reception is not that good, but it is possible Let's say up to 40m is basically satisfactory. First, install the driver from Zadig and then upload the file from the attachment to SDRSharp. The system will ask if you want to replace the existing one, give OK and it's ready. In fact, even 80m is walking, but too weak for me. One more piece of advice. Please add gain accordingly in settings. The lower the frequency, the higher the gain must be. Direct Sampling can be forgotten. With this driver, it is a waste of time and the risk of damaging the tuner. I will add that it is good to do chip cooling. The shielding itself is not as important as cooling. I use soldering points under the circuits. I put a lot of tin into the holes and then solder, for example, a flat spiral made of thick copper wire to the drop. Before soldering such a spiral, you need to unwind about 2 cm of the wire and then, after soldering under the chip, a plate should be soldered to the tip. Or solder the tip to the housing - a tin can for the old head is perfect. The antenna output can be converted to BNC. I did it this way. I took the BNC socket and used the coaxial cable retrieved from the laptop lapel. It was a hatch with a broken die I soldered the cable to the socket. I will not describe the way of earning money, because it is not a topic. I soldered the other end to the tuner hot spot. That is, where the original socket introduces the signal. For example, for the middle pin of the MCX socket. I soldered the BNC socket to the casing on the head, the tuner board was soldered to the casing on spiral wires, which are soldered with the flat side under the chips. As for the diameter of the wire, don't overdo it, about 2mm is enough, maximum 3. Of course, the thicker the wire, the better it will dissipate heat to the housing, but ... the harder it is to solder. You cannot overdo the heating under the chip, so as not to desolder the system and damage the PCB. The holes under the chip have such tubes inside. If one is overheated, it will move away from the PCB. It is true that there is no hole, but it will not pull the tin. The purpose of the tin is - because normally these systems should be soldered from the bottom, and often they are not, the mounting of the system from the bottom, and in our case it is also a heat conductor and element fixing the wire helix. The spiral can be replaced with a thicker plate. I have a copy where instead of a helix I soldered 5gr and a wire ear with a diameter of 6mm to the coin. Such a "U", a few cm high, cools very well, but can be hot. The question is, if there was no cooling, how would the chip heat up? And it can reach a temperature of over 70 degrees. And here we go back to the driver. If the device operates in the range not provided for the tuner, there are still quite extreme conditions, and the effects of the system operation may be unsatisfactory. Cooling results in a significant reduction in noise, which increases the sensitivity. The picture shows a soldered spiral with some sections - "thermowell"

Today I received rtl sdr v3 r820t2 (in a metal housing), so far I used the black R820T2 everything works, the new one does not work, the computer does not see it, what should I do to start it?

If the computer does not see it, you can forgive yourself. If it found the device but did not recognize it, it could be assumed (albeit incorrectly) that maybe something could be done. This tuner model is a regular RTL SDR with the R820T2 tuner but it is cooled by a thermocouple that touches the metal casing, and this casing acts as a screen and a heat sink. It also has a thermally compensated IC generator instead of quartz, therefore it should have virtually no drift and does not need to be calibrated. The antenna input is transformer-coupled (probably) to the RTL chip and thus we have the direct sampling option. The hot wire also has the voltage needed to power the preamplifier. Nevertheless ... in terms of the chipset and tuner used, it is the same receiver as the blue one. It should fire from the first kick. The computer cannot distinguish which is which. But if there is no "ding-dong" after connecting, it means that the chipset is damaged, or it is soldered badly at the factory, or it has come off the print job. If the tuner chip was damaged, it would be "ding-dong" but the receiver would not be receiving. If you can, return it to the seller, have it replace it, or ... give the money back.

So if I already have a correctly configured computer (Windows 10) for the black R820T2, then the new one should be on it? After inserting it into USB, the message "USB device not recognized" appears, I also have such a message on the second computer.

So she sees him but doesn't recognize him. Theoretically, he should have fun without any circuses. But try reinstalling the drivers. One question. Do you connect it directly or are you using an extension cord? Because if you are using an extension cord, change the cable. If possible, try to connect the receiver directly. Also, try plugging the device into a different port.