Date   

Re: Airspy HF+ handling mighty strong RF-signals without big issues

EB4APL
 

I am also waiting for my HF+ and my high RF environment is quite worse, a mighty MW transmitter about 3 Km away that pours some 600 KW to its antenna. I'm coping with it with a home made 1.6 MHz HP filter before my SoftRock Rx, but I'll test the HF+ without the filter to see what happens.

73 de Ignacio, EB4APL


El 09/12/2017 a las 12:36, Paul Mclaren MM0ZBH escribió:
Looking forward to testing my HF+ when it arrives on amateur topband with the RX beverages.  I have a 2kw AM broadcast on 1548khz about 2km away and it gave the RSP1 big problems which are obvious now I understand the uses and limits of the RSP1.  RSP2 is a little better but hoping for a big difference on the HF+.   

Regards

Paul

Sent from my iPad

On 9 Dec 2017, at 10:39, prog <info@...> wrote:

On Fri, Dec 8, 2017 at 11:54 pm, Mendo Mendevski wrote:
To explain the dB vs Power ratio, here is more information for someone to catch the whole picture of what I am doing here in this video:

5.5 dB = 3.55 times more RF-signal power
10.5 dB = 11.22 times more RF-signal power
16 dB = 40 times more RF-signal power
22 dB = 160 times more RF-signal power
27.5 dB = 560 times more RF-signal power
32.5 dB = 1780 times more RF-signal power
38 dB = 6300 times more RF-signal power

So, when I was applied 38 dB attenuation, it means that I was lowered the RF-signal power for 6300 times! And even after that, the RF-signal from Macedonian radio is still 79 dB (more than 79 million times) stronger than noise floor! It`s really amazing how Airspy HF+ handled such mighty powerful RF-signals without a noticeable problems!
 
Thanks Mile for the video and the explanation. Note that there is a big AGC (composed of many analog and digital AGC's) controlling all the stages of the receiver to ensure that the gain distribution is always optimal. The whole chain stays in a very comfortable operating point, far away from overloading.
The effect of the analog AGC's is compensated digitally so that the level stays the same, and the transitions are smoothed in time to avoid undesirable clicks. There is also an embedded wide band Noise Blanker that eliminates short pulsed noise, which improves the signal even further.

Most of these fancy features are implemented and/or controlled by the embedded software, so things can only improve with further updates.

I'm curious to see how the FM tuner compares to your best receivers.




Re: Using RX_TOOLS ?

Martin Smith
 

Interesting, so the Soapy layer currently supports "biastee", but not "bitpack".

I submitted a tiny patch to expose access to bitpacking, the pull is in the queue and that is all I can do. https://github.com/pothosware/SoapyAirspy/pull/13


Re: Airspy HF+ handling mighty strong RF-signals without big issues

Mendo Mendevski
 

Thanks Youssef,
I will check the new Low-IF mode when I will be back  home and catch some free time.
The FM Broadcast band too.
Regards,
Mile Kokotov, Z33T


On Saturday, December 9, 2017 2:43 PM, prog <info@...> wrote:


On Fri, Dec 8, 2017 at 11:54 pm, Mendo Mendevski wrote:
To explain the dB vs Power ratio, here is more information for someone to catch the whole picture of what I am doing here in this video:

5.5 dB = 3.55 times more RF-signal power
10.5 dB = 11.22 times more RF-signal power
16 dB = 40 times more RF-signal power
22 dB = 160 times more RF-signal power
27.5 dB = 560 times more RF-signal power
32.5 dB = 1780 times more RF-signal power
38 dB = 6300 times more RF-signal power

So, when I was applied 38 dB attenuation, it means that I was lowered the RF-signal power for 6300 times! And even after that, the RF-signal from Macedonian radio is still 79 dB (more than 79 million times) stronger than noise floor! It`s really amazing how Airspy HF+ handled such mighty powerful RF-signals without a noticeable problems!
 
Mile, I just added a Low-IF mode in SDR# to move the center of the spectrum away off the spectrum when using sample rates <= 192kHz. This should help making better videos.

Revision 1630 is now available for public download: http://airspy.com/download



Virus-free. www.avast.com


Re: Airspy HF+ handling mighty strong RF-signals without big issues

prog
 

On Fri, Dec 8, 2017 at 11:54 pm, Mendo Mendevski wrote:
To explain the dB vs Power ratio, here is more information for someone to catch the whole picture of what I am doing here in this video:

5.5 dB = 3.55 times more RF-signal power
10.5 dB = 11.22 times more RF-signal power
16 dB = 40 times more RF-signal power
22 dB = 160 times more RF-signal power
27.5 dB = 560 times more RF-signal power
32.5 dB = 1780 times more RF-signal power
38 dB = 6300 times more RF-signal power

So, when I was applied 38 dB attenuation, it means that I was lowered the RF-signal power for 6300 times! And even after that, the RF-signal from Macedonian radio is still 79 dB (more than 79 million times) stronger than noise floor! It`s really amazing how Airspy HF+ handled such mighty powerful RF-signals without a noticeable problems!
 
Mile, I just added a Low-IF mode in SDR# to move the center of the spectrum away off the spectrum when using sample rates <= 192kHz. This should help making better videos.

Revision 1630 is now available for public download: http://airspy.com/download


Re: Using RX_TOOLS ?

Ruben Navarro Huedo (EA5BZ)
 

Yes...i know it is supported by Soapy Airspy Module.
But... How can i call that parameter from RX_TOOLS?

Thank's for your help.


Re: Airspy HF+ handling mighty strong RF-signals without big issues

Paul Mclaren MM0ZBH
 

Looking forward to testing my HF+ when it arrives on amateur topband with the RX beverages.  I have a 2kw AM broadcast on 1548khz about 2km away and it gave the RSP1 big problems which are obvious now I understand the uses and limits of the RSP1.  RSP2 is a little better but hoping for a big difference on the HF+.   

Regards

Paul

Sent from my iPad

On 9 Dec 2017, at 10:39, prog <info@...> wrote:

On Fri, Dec 8, 2017 at 11:54 pm, Mendo Mendevski wrote:
To explain the dB vs Power ratio, here is more information for someone to catch the whole picture of what I am doing here in this video:

5.5 dB = 3.55 times more RF-signal power
10.5 dB = 11.22 times more RF-signal power
16 dB = 40 times more RF-signal power
22 dB = 160 times more RF-signal power
27.5 dB = 560 times more RF-signal power
32.5 dB = 1780 times more RF-signal power
38 dB = 6300 times more RF-signal power

So, when I was applied 38 dB attenuation, it means that I was lowered the RF-signal power for 6300 times! And even after that, the RF-signal from Macedonian radio is still 79 dB (more than 79 million times) stronger than noise floor! It`s really amazing how Airspy HF+ handled such mighty powerful RF-signals without a noticeable problems!
 
Thanks Mile for the video and the explanation. Note that there is a big AGC (composed of many analog and digital AGC's) controlling all the stages of the receiver to ensure that the gain distribution is always optimal. The whole chain stays in a very comfortable operating point, far away from overloading.
The effect of the analog AGC's is compensated digitally so that the level stays the same, and the transitions are smoothed in time to avoid undesirable clicks. There is also an embedded wide band Noise Blanker that eliminates short pulsed noise, which improves the signal even further.

Most of these fancy features are implemented and/or controlled by the embedded software, so things can only improve with further updates.

I'm curious to see how the FM tuner compares to your best receivers.


Re: Using RX_TOOLS ?

Evariste Courjaud
 

Biastee seems to be supported with "biastee=true"


Re: Using RX_TOOLS ?

jdow
 

Nope. It's not likely a problem that can be fixed from here.
{^_^}

On 2017-12-09 03:02, Ruben Navarro Huedo (EA5BZ) wrote:
Hello Jdow:
I wrote developers some months ago and i have no answer :-(
And i want use rx_tools becouse i want receive automatically some SATS with my Raspberry.
with rx_fm (the same as rtl_fm but with Airspy support) i can receive FM and save it.
with rx_sdr (the same as rtl_sdr but with Airspy support) i can save IQ.
Do you know any alternative to them?
Thank's a lot.


Re: Using RX_TOOLS ?

Ruben Navarro Huedo (EA5BZ)
 

Hello Jdow:

I wrote developers some months ago and i have no answer :-(
And i want use rx_tools becouse i want receive automatically some SATS with my Raspberry.
with rx_fm (the same as rtl_fm but with Airspy support) i can receive FM and save it.
with rx_sdr (the same as rtl_sdr but with Airspy support) i can save IQ.
Do you know any alternative to them?

Thank's a lot.


Re: Airspy HF+ handling mighty strong RF-signals without big issues

prog
 

On Fri, Dec 8, 2017 at 11:54 pm, Mendo Mendevski wrote:
To explain the dB vs Power ratio, here is more information for someone to catch the whole picture of what I am doing here in this video:

5.5 dB = 3.55 times more RF-signal power
10.5 dB = 11.22 times more RF-signal power
16 dB = 40 times more RF-signal power
22 dB = 160 times more RF-signal power
27.5 dB = 560 times more RF-signal power
32.5 dB = 1780 times more RF-signal power
38 dB = 6300 times more RF-signal power

So, when I was applied 38 dB attenuation, it means that I was lowered the RF-signal power for 6300 times! And even after that, the RF-signal from Macedonian radio is still 79 dB (more than 79 million times) stronger than noise floor! It`s really amazing how Airspy HF+ handled such mighty powerful RF-signals without a noticeable problems!
 
Thanks Mile for the video and the explanation. Note that there is a big AGC (composed of many analog and digital AGC's) controlling all the stages of the receiver to ensure that the gain distribution is always optimal. The whole chain stays in a very comfortable operating point, far away from overloading.
The effect of the analog AGC's is compensated digitally so that the level stays the same, and the transitions are smoothed in time to avoid undesirable clicks. There is also an embedded wide band Noise Blanker that eliminates short pulsed noise, which improves the signal even further.

Most of these fancy features are implemented and/or controlled by the embedded software, so things can only improve with further updates.

I'm curious to see how the FM tuner compares to your best receivers.


Re: Spyserver for testing

Dick
 

Hi Jesús,  that works great.
 
When I select a Spyserver bandwidth of 125kHz or lower like 62.5 kHz in this example, I can check the “Use full IQ” box.
Then selecting RAW and a bandwidth of 16.000 I can decode VDL2 on 136.975 using VAC and MultiPSK.
136.975 is very busy and shows the identification messages of ground stations at Barcelona Airport (see below).
Also found a few signals on 136.775, but so far non on the other two VDL2 frequencies 136.725 and 136.875.  
 
image
 
 
Thanks for giving me the opportunity to ID these 2 SITA ground stations (hexa): 210DD7 (hexa): 210DD8
 
 
12/09/17 08:28:37 UTC
Broadcast address (hexa): FFFFFF (All aircraft)
Source address (hexa): 210DD7 (Ground Station, delegated address , On the ground , command frame)
XID (Exchange Identification) frame F=0
Data (hexa): 828000140109383838353A3139393302020001030320A488F0001F000156040120C1044C45424CC406000000000000C50494000000C80319D015
Public parameters:HDLC public parameter: 8885:1993
Classes of procedures (hexa): 0001
HDLC functions (hexa): 20A488
Private parameter set identifier: V
AVLC specific options parameter (hexa): 20
Airports covered by the ground station: LEBL BARCELONA AIRPOR (SPAIN)
ATN router nets:
  * ADM identifier (hexa): 000000   User field (hexa): 000000
Station operator mask (address) (hexa): 200000
Ground station (+/- 3'): 41°18'N 002°06'E
 
12/09/17 08:29:53 UTC
Broadcast address (hexa): FFFFFF (All aircraft)
Source address (hexa): 210DD8 (Ground Station, delegated address , On the ground , command frame)
XID (Exchange Identification) frame F=0
Data (hexa): 828000140109383838353A3139393302020001030320A488F0001F000156040120C1044C45424CC406000000000000C50494000000C80319D015
Public parameters:HDLC public parameter: 8885:1993
Classes of procedures (hexa): 0001
HDLC functions (hexa): 20A488
Private parameter set identifier: V
AVLC specific options parameter (hexa): 20
Airports covered by the ground station: LEBL BARCELONA AIRPOR (SPAIN)
ATN router nets:
  * ADM identifier (hexa): 000000   User field (hexa): 000000
Station operator mask (address) (hexa): 200000
Ground station (+/- 3'): 41°18'N 002°06'E
 
Cheers,
Dick
 
 

From: Jesus Rodriguez
Sent: Friday, December 8, 2017 21:47
To: main@airspy.groups.io
Subject: Re: [airspy] Spyserver for testing
 
Hi Dick,
 
I’ve been trying to get the full IQ option from the spyserver configuration but could not do it. Now “force_8bit” option is commented. Can you try just in case?.
 
Regards.


Airspy HF+ handling mighty strong RF-signals without big issues

Mendo Mendevski
 

To explain the dB vs Power ratio, here is more information for someone to catch the whole picture of what I am doing here in this video:

5.5 dB = 3.55 times more RF-signal power
10.5 dB = 11.22 times more RF-signal power
16 dB = 40 times more RF-signal power
22 dB = 160 times more RF-signal power
27.5 dB = 560 times more RF-signal power
32.5 dB = 1780 times more RF-signal power
38 dB = 6300 times more RF-signal power

So, when I was applied 38 dB attenuation, it means that I was lowered the RF-signal power for 6300 times! And even after that, the RF-signal from Macedonian radio is still 79 dB (more than 79 million times) stronger than noise floor! It`s really amazing how Airspy HF+ handled such mighty powerful RF-signals without a noticeable problems!






73!
Mile Kokotov, Z33T

Virus-free. www.avast.com


Re: Using RX_TOOLS ?

jdow
 

Perhaps the answer is either, "Don't use rx_tools or take the problem to the rx_tools developer(s)."

{^_^}

On 2017-12-08 13:17, Ruben Navarro Huedo (EA5BZ) wrote:
I am speaking about rx_tools
Not SDR#


Re: Using RX_TOOLS ?

Ruben Navarro Huedo (EA5BZ)
 

I am speaking about rx_tools
Not SDR#


Re: Spyserver for testing

Jesus Rodriguez
 

Hi Brendan,

Yes, not much activity these days on 2m band… now some voice activity and some echo-links in different frequencies.

Thanks for testing.

Regards.

On 6 Dec 2017, at 17:18, Brendan Wahl <bjwahl59@gmail.com> wrote:

Works very well here, from the west coast of the US. Some latency issues it seems, as the waterfall stopped and the audio dropped out very briefly from time to time. I was able to hear/see packet signals, but everyone else seems to be out having tapas and drinks!

Brendan WA7HL




Re: Spyserver for testing

Jesus Rodriguez
 

Hi Dick,

I’ve been trying to get the full IQ option from the spyserver configuration but could not do it. Now “force_8bit” option is commented. Can you try just in case?.

Regards.


On 6 Dec 2017, at 18:37, Dick <hobbyd@...> wrote:

Hi Jesús,
 
Some time ago I had someone else playing with the spyserver settings and although we didn’t fully understand the possible repercussions (negative effect), the following worked:
 
Commenting out the "force_8bit" from the spyserver config file.
The result was that in SDR# now “Use full IQ” and the IQ Format can be selected.

 
<image[1].png>
 
Can you give this a try?
 
73, Dick
 
 
From: Jesus Rodriguez
Sent: Tuesday, December 5, 2017 20:46
To: main@airspy.groups.io
Subject: Re: [airspy] Spyserver for testing
 
Hi Dick,
 
I tried to change the bandwidth but seems i could not find the right parameter/value. Can someone point me to the server.config parameter to allow the 12Khz needed bandwidth?.
 
Regards.
 

On 5 Dec 2017, at 17:19, Dick <hobbyd@...> wrote:
 
Hello Jesús,

Your Spyserver works fine, but.....

I am interested in identifying VDL2 ground stations. VDL2 Modulation is done in D8PSK (Differentially encoded 8 Phase Shift Keying). Small messages (in "bursts") are transmittted at 10500 bauds.

A lot of VDL2 signals are visible on 136.975 MHz.
Unfortunately I cannot set the desired bandwidth in SDR# which is needed to decode them using MultiPSK.
It seems it is limited to 9.765 using mode: RAW or 4.882 using mode: USB.
To decode the VDL2 signals using MultiPSK I need a bandwidth of 12 KHz.

Can you change your setting to enable this wider bandwidth, if only for a short time so I can ID the ground station in your area?

73, Dick  (PA-2015, NL-13560)



-----Original Message----- From: Jesus Rodriguez
Sent: Tuesday, December 5, 2017 13:09
To: main@airspy.groups.io
Subject: [airspy] Spyserver for testing

Hello,

Please, can you test and let me know how does the following spyserver work?:

sdr://jerocu.no-ip.org:5555

It’s an Airspy connected to an Odroid-XU4 and dual-band V/U Diamond X50 antenna. Control enabled for the first user and no limit on high/low frequencies. 2.5M sample rate as 10M has performance problems with the Odroid-XU4 board.

This is next to Barcelona airport and harbour.

Thanks and regards.

Jesús - EA3CLB
 


Re: Using RX_TOOLS ?

Roberto Zinelli
 

Use biast check box in sdr#

Inviato da OldPhone

Il giorno 08 dic 2017, alle ore 21:07, Ruben Navarro Huedo (EA5BZ) <runahue@...> ha scritto:

Hello:
Is anybody using rx_tools? https://github.com/rxseger/rx_tools
I have tested it with my Airspy and all is fine but i need enable Airspy BIAS-T
Do you know how could i do it?
Tnx a lot.


Using RX_TOOLS ?

Ruben Navarro Huedo (EA5BZ)
 

Hello:
Is anybody using rx_tools? https://github.com/rxseger/rx_tools
I have tested it with my Airspy and all is fine but i need enable Airspy BIAS-T
Do you know how could i do it?
Tnx a lot.


Re: How to setup / make public the server #spyserver

John
 

portforward.com is a useful site.
Router specific assistance.

John


Re: Airspy HF+ on VHF

Dana Myers
 

On 12/8/2017 10:05 AM, Mendo Mendevski via Groups.Io wrote:
Another video comparison between New Airspy HF+ SDR-receiver and ColibriNANO SDR. This time on VHF VOLMET signal (124.325 MHz)
Antenna is Vertical Dipole
In the first part of the video, The signal from antenna is connected directly to antenna input of the receivers. In the second part of the video, the -32 dB external attenuator is connected between the antenna and SDR input.

Airspy HF+ can clearly receive VHF Volmet signal even with 32 dB external attenuator.
ColibriNANO can not in both cases.

Airspy HF+ is serious about the '+'!

Thanks,
Dana  K6JQ

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