Is my SDR faulty?

[blinky]

Hi,

 

I just received my RTL-SDR dongle and had it picking up local FM stations at home, Im now up north at my caravan, have stuck the aerial outside and picked up a strong signal on 98.3, which I assume is an FM station.....  I click WFM but don't hear anything but noise, am I doing something wrong or is it faulty, or is there genuinely no station there!

 

 

[furrysocks2]

You can appear to get a signal dead-center in the band you're looking at, but I though "Correct IQ" got rid of it, not sure. It may well be that there is no station being broadcast on 98.3 within range of where you are now. Zoom out with the slider top right and perhaps play with AGC/gain in the configuration dialog and see if there's anything visible then.

[blinky]

Had a cunning plan..... went to the car and tuned to that frequency - just seemed to go quiet with no audio, same as the SDR.  Im now recording a weather sat pass - how does this look, any tips from anybody?

[Carl Reade]

Looks way too narrow for station. Check if noise level changes when aerial connected. Would also widen the band to the max.

[blinky]

Hmm.... the online tutorial said to have bandwidth at about 36Khz

[Carl Reade]

1 minute ago, blinky said:

Hmm.... the online tutorial said to have bandwidth at about 36Khz

I was referring to your first post😀

On the weather one the best results I've had was using a horizontal V antenna and a LNA4ALL preamp and a decent pass helps a lot.

[blinky]

Just now, Carl Reade said:

I was referring to your first post😀

On the weather one the best results I've had was using a horizontal V antenna and a LNA4ALL preamp and a decent pass helps a lot.

Ah, ok, see what you mean!  That's the setup I have.  Put the supplied dipole into a v shape and have it pointing north lying flat on a garden table outside the van with the LNA close to the antenna.  Is ther eother software or anything I should use?

[Carl Reade]

29 minutes ago, blinky said:

Ah, ok, see what you mean!  That's the setup I have.  Put the supplied dipole into a v shape and have it pointing north lying flat on a garden table outside the van with the LNA close to the antenna.  Is ther eother software or anything I should use?

Software is fine. To improve a quad helix or turnstile would help both not easy to build. Overall I found I generally I got one decent quality pass a day. Here are my decent ones.

 

[blinky]

Very nice!  What antenna/setup do you have?  And is there a way to know if its going to be a good pass or not in advance or is it luck?

[Carl Reade]

1 hour ago, blinky said:

Very nice!  What antenna/setup do you have?  And is there a way to know if its going to be a good pass or not in advance or is it luck?

Just a horizontal V and LNA. I used WXtrack software to look at the passes.

[blinky]

I don't seem to be having much joy at all - will keep persevering 

[Alan White]

A question gents, are you trying to get data from the satellites?

All this radio stuff is new to me, well this use is anyway.

[blinky]

Yeah you can download the weather satellites transmissions and decode them - well some people can, I'm not having any luck!

[blinky]

Todays pass on 137.1Mhz and nada!  This is with the LNA amp up and running and the antenna outside lying flat on a table pointed north in the V shape, I cant see what Im doing wrong unless I need to have a different antenna or something is wrong with my location in WXtoIMG?

[wxsatuser]

19 minutes ago, blinky said:

Todays pass on 137.1Mhz and nada!  This is with the LNA amp up and running and the antenna outside lying flat on a table pointed north in the V shape, I cant see what Im doing wrong unless I need to have a different antenna or something is wrong with my location in WXtoIMG?

Get your antenna up on a pole, high as possible.

137.1MHz is NOAA 19 which is PM prime service, best pass starts around 16.15utc South overhead to North ends around 1628utc

[blinky]

whats PM prime service?  Afraid I don't have any way of raising the height of the antenna, just starting out so don't have a pole or anything to mount it on

[wxsatuser]

Afternoon service ascending, there will of course be a good pass over night as well decending.

Hold the antenna up by hand if needed.

[wxsatuser]

Sorry the decending pass is around 0610utc, North to South overhead

[Carl Reade]

1 hour ago, Alan White said:

A question gents, are you trying to get data from the satellites?

All this radio stuff is new to me, well this use is anyway.

Basically these satellites orbit constantly transmitting live weather pictures. So the aim is to wait for it to pass overhead, tune to it's frequency, decode the signal using software and produce a picture.

[Alan White]

10 hours ago, Carl Reade said:

Basically these satellites orbit constantly transmitting live weather pictures. So the aim is to wait for it to pass overhead, tune to it's frequency, decode the signal using software and produce a picture.

That sounds a fun challenge if you are technical enough.