USB Isolator?

[Your_account]

I did the roll of coax

what did you mean with?

 

[dave3825]

what did you mean with?

I had good result with the first one. The rest are the claims of the author in this link and I have not tried the rest. Only had a short coax here and don't have an extra car battery...

SDR for Mariners Moved to RTL-SDR for Everyone: Reducing electrical noise


USB plug metal connected to 1m coax: coax cable center conductor connected to the metal support of the USB plug. Decreased noise by 7db. Saw improvement

USB plug metal connected to 10m wire: further noise reduction by 5dB.

USB plug metal connected to 12V car battery negative (-) terminal: noise almost completely eliminated.

USB plug support connected to 10m coax, RTL stick nesting in the middle: noise completely eliminated.



Click pik to enlarge






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[M105]

Can somebody explain how or why the negative post on the old car battery is supposed to work? I have never heard of such.

 

[Your_account]

what should the long coax do? I have 10 or more Dongles so 10 or more coax cables?!

 

[dave3825]

Try it on one dongle. If it works, then go from there. If you never move or rearrange them, then you could maybe find a way to join all together... I did it with my Airspy and did see a difference. Keep in mind that I am surrounded by rfi as I am in an apartment..

 

[bharvey2]

One pass through a ferrite bead may not be enough. If you use the larger snap on ones, you can wrap the USB cable through it a number of times and gain greater noise suppression.

 

[Your_account]

you can wrap the USB cable through it a number of times and gain greater noise suppression.

I do.

I did it with my Airspy and did see a difference.

Do you have pictures from before and after? I see it in SDR# when i boot an Pi up.

 

[Pape]

Can somebody explain how or why the negative post on the old car battery is supposed to work? I have never heard of such.

Did not read the things but back in the day we were using car battery to filter electrical noise from car charger powering cb radio.

 

[Rred]

"A ferrite bead" can be a total waste of time and money unless it is the correct mix (Type43, Type 31, etc.) to attenuate the frequency of the interfering signals.

Car batteries (any battery) act like a giant capacitor, they can absorb and swamp out a great deal of transient line noise. Sometimes. Often but not always. And that's assuming the noise is "in the line" that is being grounded to them.

 

[M105]

Did not read the things but back in the day we were using car battery to filter electrical noise from car charger powering cb radio.

Yes, I understand using a battery to filter a power supply but this article says to connect the metal part of the USB connector to the negative terminal of an old car battery. Essentially use the old battery as a "ground". It sounds like a 35 pound pile of lead bull manure to me...

 

[Your_account]

I dont have anything to charge an Battery.

Which Bandwidth need an ordinary SDR Dongle?

 

[Rred]

"It sounds like a 35 pound pile of lead bull manure to me..."

Confucius said the exact same thing. You're among the few wise ones.

 

[slicerwizard]

Yes, I understand using a battery to filter a power supply but this article says to connect the metal part of the USB connector to the negative terminal of an old car battery. Essentially use the old battery as a "ground". It sounds like a 35 pound pile of lead bull manure to me...

These fixes are promoted by folks who have no idea what they're doing. Running a wire to a car battery provides a random counterpoise that may improve RSSI. Since the signal sounds better, the battery, with only one side connected to anything, is obviously a "noise filter"...

 

[M105]

Thanks Slicer. That makes some sense out of it. An old aluminum pie plate would be a lot easier to carry around and not mess the floor as bad when it tipped over...