In that case it should all be automagic...

On Thu, Jan 11, 2018 at 03:15 am, <pbij2001@...> wrote:

You are only using half the dynamic range of the receiver :-)

That would be true if there wan't any AGC involved. But we have this:

On Thu, Jan 11, 2018 at 12:49 am, adam9a4qv wrote:

Alan, we do not spend the $10k in antenna mast and antennas to put the 40db attenuator on the receiver!

If your noise floor is as high as -55dBm and a broadcaster is clearly hitting 0dBm, I think you should.
You are only using half the dynamic range of the receiver :-)

On Thu, Jan 11, 2018 at 03:00 am, jdow wrote:

Oh yes you do. If you can connect the antenna and have the noise go up more than about 3dB you have room for attenuation. And any decent transmitting antenna will have room for as much as 20 dB attenuation at quiet locations on the Earth, not in buildings, caves, or congresscreature's brains.

Keyword: quiet

On Wed, Jan 10, 2018 at 10:30 pm, Alan G4ZFQ wrote:

Ruben,

Look at the noise level, 40dB or more attenuation should be used.

73 Alan G4ZFQ

Remember, there's an AGC with enough range to cover up to +15 dBm without saturation.
Leave the decision to use the right amount of attenuation to the AGC.

The problems I see in that screenshot:

1. The SNR of the strong BC station is ... rather low for the antenna you are using. This means your antenna is picking a lot of noise. Bad isolation from the PC?
2. I can see the same signal on Simon's and Alex's servers with the same splatter. Different locations, different antennas.
3. Update your SDR#

Oh yes you do. If you can connect the antenna and have the noise go up more than about 3dB you have room for attenuation. And any decent transmitting antenna will have room for as much as 20 dB attenuation at quiet locations on the Earth, not in buildings, caves, or congresscreature's brains.

{^_^}

Simon: i will test this night with 768khz.

On 1/11/2018 1:55 AM, David J Taylor via Groups.Io wrote:

From: Ronneil Camara

Thank you David. My goal is to be able to build a setup that will allow me to capture full disk of earth from GOES satellite.

For 137MHz reception, the Airspy HF+ might be the bee's knees.

Dana K6JQ

From: Ronneil Camara

Thank you David. My goal is to be able to build a setup that will allow me to capture full disk of earth from GOES satellite. I read from few blogs the Mini is capable. I hope those bloggers are telling the truth. Anyways, I'm worried about the other thread I saw about Airspy Mini and drivers not working well. Is Airspy Mini supported well in linux/mac and other unix variants like FreeBSD?
============================

Neil,

Best to get real advice from people who have actually done GOES reception. Might be an idea to check on Twitter as well.

I've not used these devices enough with Linux to comment, except that they work well with the Raspberry Pi at 1.09 GHz.

Cheers,
David
--
SatSignal Software - Quality software written to your requirements
Web: http://www.satsignal.eu
Email: david-taylor@...
Twitter: @gm8arv

Alan, we do not spend the $10k in antenna mast and antennas to put the 40db attenuator on the receiver!

Adam,

I've never had the good fortune to use such an antenna.
But I thought the purpose was to put 40dB on the TX signal, not to overload the RX.
It looks to me that the visible station is at 0dBfs. A BPF will not help with strong signals close to the frequency in use.
Or, is there something I'm missing?

73 Alan G4ZFQ

Alan, we do not spend the $10k in antenna mast and antennas to put the 40db attenuator on the receiver!

Ruben, welcome to the club :-)..... you need a bandpass filter for each HF band you want to listen.

Adam

Alan....external attenuation?

Ruben,

"2 elements monoband beam 30m over the ground"

On 40m an attenuator can help with a low dipole. You have about 70dB of antenna noise, your screenshot shows you have less than 60dB headroom.

73 Alan G4ZFQ

Alan....external attenuation?

Great, I’ve been wanting to try SdrDx for a long time. Thanks!

Our other software doesn't measure SNR directly but it is around the same.

received my HF+
We have been testing it with a 2 elements monoband beam 30m over the ground.
We are suffering saturation from broadcasting on 7200 and UP.
We own other SDR and have tested also today and they don't have this problem.
What do you think?

Ruben,

Look at the noise level, 40dB or more attenuation should be used.

73 Alan G4ZFQ

Hi Ruben - it is direct SDRSharp Plugin to Yaesu CAT. I modified the C# .NET code (for Kenwood) from the UzixLS project.

Connecting OMNIRIG to the Plugin may  be possible. I may look at the OMNIRIG source code sometime but at present enjoying the operation.

de Wb8yqj Don