Want to reduce noise on the RTL2832U???

Of course we can if you know what you are doing. It is possible. A japanese experimenter proved it.

Improving HF Reception By Disconnecting the Switching Power Supply on the RTL-SDR - rtl-sdr.com

Go there and do some reading and test it then it can be proven and worthy of RTL-SDR wiki at RR.

bigbean said:

Of course we can if you know what you are doing. It is possible. A japanese experimenter proved it.

Improving HF Reception By Disconnecting the Switching Power Supply on the RTL-SDR - rtl-sdr.com

Go there and do some reading and test it then it can be proven and worthy of RTL-SDR wiki at RR.

Click to expand...

I wonder how true that is, and if the difference was not simply band conditions. How long was the time lag between tests?

Still, I'm not fan of switching supplies.

I also wonder how he did the HF receive mod... I don't see any obvious mod signs.

Voyager said:

I wonder how true that is, and if the difference was not simply band conditions. How long was the time lag between tests?

Still, I'm not fan of switching supplies.

I also wonder how he did the HF receive mod... I don't see any obvious mod signs.

Click to expand...

4 things here about this.

1)No hardware mod will be shown if using a up converter.
2)SDR sharp is the only interface that has the rtlsdr.dll modded for HF reception.
3)HDSDR (as shown) has no modded driver for HF reception.up converters or direct sampling mods have to be used.
4)Band conditions has no bearing on the noise level generated by the dongle

Time lag 3 minutes same day which doesn't prove falseness. Its right there in the image HDSDR has a clock and calender.

rtlsdr.com is just a site that sort of announces ways of using and modding the dongle. If they feel it's legitimate they will make the article. For cynical types be assured anything is possible. If you have Google Chrome you can go to the guys website (translate it) which is in Japanese where the original documentation is.

The community behind it is on freenode ##rtlsdr go ask them about it. They work with rtlsdr daily. I posted here in RR to have people know the noise level can be reduced. I am sure the Japanese experimenter has tried capacitors with no luck so added the new diodes and removing the other one gave him less noise. Wouldn't we see a mod with capacitors instead of diodes?

From the looks of it takes a steady hand, etching skills, and good smt solder skill which is not easy because of the size of the components. I won't attempt it. Only thing I done to mine was remove the remote sensor diode out of two of my dongles and re soldered some connections that looked weak.

bigbean said:

Only thing I done to mine was remove the remote sensor diode out of two of my dongles

Click to expand...

Just curious - why did you do that?

I would guess because:

1) It has no function for our purpose.
1) Active diodes predominately generate noise.


What do you mean, I used "1" twice? Don't you know that 1+1= 2?

eorange said:

Just curious - why did you do that?

Click to expand...

To experiment with the dongle based on someone's find from experimenting. It reduces some of the out of band interference. That diode is too close to the mcx antenna connector. That diode is on regardless of a driver. I have noticed a very small increase of weaker signals. The cynical will disagree. I listen on HF with Nooelec ham it up up converter so I will try anything within my ability to lessen the noise level.

bigbean said:

4 things here about this.

1)No hardware mod will be shown if using a up converter.
2)SDR sharp is the only interface that has the rtlsdr.dll modded for HF reception.
3)HDSDR (as shown) has no modded driver for HF reception.up converters or direct sampling mods have to be used.
4)Band conditions has no bearing on the noise level generated by the dongle

Time lag 3 minutes same day which doesn't prove falseness. Its right there in the image HDSDR has a clock and calender.

Click to expand...

OK. I didn't see the clock/calender. But band conditions DO affect RF noise which will show up on a spectral display. Just listen to 10M during the day vs night. Night is a lot more quiet.

In short, my modded RTL may not suffer the same issue as an upconverter (which may be what is generating additional noise).

Voyager said:

OK. I didn't see the clock/calender. But band conditions DO affect RF noise which will show up on a spectral display. Just listen to 10M during the day vs night. Night is a lot more quiet.

In short, my modded RTL may not suffer the same issue as an up-converter (which may be what is generating additional noise).

Click to expand...

Voyager no man when I said band conditions do not affect the noise generated by the dongle I meant that internal noise that is always there unless action is taken to reduce the noise level. I am correct saying this. I have -103db noise floor with or without up converter.

As always we dont have to do any modding with connecting a good low noise rf amplifier that effectively boosts signals. These can overload the dongle so we have to lower the RF gain which also lowers the noise floor and more signals start to appear on the waterfall.