What is wrong with my RTL-SDR Dongle?

[AngWay]

Does anyone know what causes this. notice the bottom of the waterfall, That is normal it's showing the signal and everything is good and then about every minute or so i will see the top part of the waterfall do this. i have played around with the gain and everything else but nothing fixes it. does anyone know what the problem is? also when it does this my control channel drops to idle. This happens on both dongles also Thanks in advance

 

[dlwtrunked]

View attachment 166366
View attachment 166368
Does anyone know what causes this. notice the bottom of the waterfall, That is normal it's showing the signal and everything is good and then about every minute or so i will see the top part of the waterfall do this. i have played around with the gain and everything else but nothing fixes it. does anyone know what the problem is? also when it does this my control channel drops to idle.

This looks like overload from a strong nearby signal. But you say you turned down the gain. What if you do not hook up an antenna--does it still do that? and what antenna are you using?

 

[merlin]

Two things I see looking at trunked frequencies. Other than control channels, signals will come and go. Normal.
Looks like you have a strong signal out of band desensing the dongle.
You could try some attenuation in front of the dongle or turn your IF gain down but high enough to still get your desired channels.
If that fails, you need a spectrum analyzer to find the offending frequency and obtaining a notch filter for it.

 

[dlwtrunked]

Two things I see looking at trunked frequencies. Other than control channels, signals will come and go. Normal.
Looks like you have a strong signal out of band desensing the dongle.
You could try some attenuation in front of the dongle or turn your IF gain down but high enough to still get your desired channels.
If that fails, you need a spectrum analyzer to find the offending frequency and obtaining a notch filter for it.

We were typing at the same time and think the same thing.

 

[AngWay]

Two things I see looking at trunked frequencies. Other than control channels, signals will come and go. Normal.
Looks like you have a strong signal out of band desensing the dongle.
You could try some attenuation in front of the dongle or turn your IF gain down but high enough to still get your desired channels.
If that fails, you need a spectrum analyzer to find the offending frequency and obtaining a notch filter for it.

i have a j pole and i have a fm filter on it and a lna

 

[AngWay]

This looks like overload from a strong nearby signal. But you say you turned down the gain. What if you do not hook up an antenna--does it still do that? and what antenna are you using?

i have a j pole and i have a fm filter on it and a lna

 

[AngWay]

We were typing at the same time and think the same thing.

I'm seeing this to notice at the bottom in the events tab it's showing alias that it's picking up but it ain't playing them at all. super strange to me.

 

[rivardj]

i have a j pole and i have a fm filter on it and a lna

Try running without the LNA.

 

[AngWay]

I'm seeing this to notice at the bottom in the events tab it's showing alias that it's picking up but it ain't playing them at all. super strange to me.

yea i was thinking about doing that but i just tried turning the gain down really low i was keeping it between 200 and 250 i went down to 86 and it fixed the issue but i'm still seeing those talkgroups show up in the event tab but not showing in the now playing part. it's like it's picking them up but not showing it.

 

[RMason]

yea i was thinking about doing that but i just tried turning the gain down really low i was keeping it between 200 and 250 i went down to 86 and it fixed the issue but i'm still seeing those talkgroups show up in the event tab but not showing in the now playing part. it's like it's picking them up but not showing it.

You may want to expand the width of the Details column in the events window to see the entire message.

Also, do you see any errors in the command window (such as Tuner Unavailable messages)? Are you using a 2nd dongle? The 159.3285 frequency that is being rejected is outside the bandwidth of a single dongle.

 

[RMason]

This looks like overload from a strong nearby signal

It looks like there is a very strong signal around 152.27Mhz. Is there correlation between when this signal is active and the interference?

 

[AngWay]

It looks like there is a very strong signal around 152.27Mhz. Is there correlation between when this signal is active and the interference?

View attachment 166380

I'm not sure but after lowering my gain to 86 which i had never lowered it to that before it stopped that from happening

 

[dlwtrunked]

It looks like there is a very strong signal around 152.27Mhz. Is there correlation between when this signal is active and the interference?

View attachment 166380

Yes, his signal is certainly a candidate as pagers on that particular frequency and other frequencies are often the cause of receiver overload and intermod. PAR makes notch filters for that (although recently communications with the company have been problematical).

VHF-DN152P Specifications and Plot | PAR Electronics