Date   

Re: Mystery mode

jdow
 

Roughly speaking where are you located? Are there military or protest sites anywhere near you? That definitely looks like some form of covert comm.

{^_^}

On 20220709 08:05:18, Ken Sejkora wrote:

Thank you, Gary.  The signal is not there all the time; it was there yesterday, Fri:08-Jul around 11:30 UTC, but wasn’t there several times when I checked this morning, Sat:09-Jul.  As stated in my original post, I usually notice it when I tune into WWV at 15 MHz, or when I’m listening to the upper part of the 20-meter band and see the blips in the waterfall above 14.5 MHz.  Given the frequency, I don’t believe it to be local to New England (Kriss up in NH often sees it as well), and is likely propagation from somewhere more distant, although CHU on 14670 kHz was coming in when I took the screenshot yesterday.  Next time I notice it, I’ll check what regions are ‘skipping’ in on 20-meters, and also check WWV and other commercial stations to get a sense of propagation while I’m seeing the mystery signal.

 

If it is some type of frequency-hopping communication mode, I’m impressed that it is spanning a frequency range of about 700 kHz.  That’s pretty big at HF frequencies, but maybe not so up in the VHF and UHF bands.

 

By the way, my monitoring here is with SDR Console, Airspy HF+ Discovery, fed from a random longwire coupled through a 9:1 unun.

 

Thanks again.  Have a great weekend.

 

Ken

 

From: GARY W RUSSELL
Sent: Saturday, July 9, 2022 09:46 AM
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Mystery mode

 

After enlarging the screen shot I see what you are talking about. I’ve actually been monitoring 14 MHz lately and have never noticed that phenomenon before here in Central, IL. I am using  SDR Console, Airspy HF+Discovery and a Wellbrook Loop antenna. I will watch for it though,
Gary

 


51F5A9883D9D44DFA830C7DE8C6FCFE1.png

C3C7DB19F0DD4C4F957778DF09823B48.png


Re: Mystery mode

jdow
 

Receive them on post processing. But, then you would have to figure out how to demodulate and decrypt them. If they don't all more or less start and end at the same time you may have multiple hopping and likely encrypted nets operating.

{o.o}

On 20220709 04:43:12, Kriss Kliegle KA1GJU wrote:

I've seen them too from southeast NH. The 'pips' are too random for QRM, I was thinking spread spectrum comms myself.
It's hard to actually listen to them, due to not appearing on the same frequency over short periods of time.

73 Kriss KA1GJU


Re: Optimal RF filter placement/location

jdow
 

Small quibble - an all metal adapter is OK. Avoid adapter cables, though. And a ferrite bead good for the pertinent frequencies on the antenna cable at the input of the filter won't hurt and may help considerably depending on your exact situation.

{^_^}

On 20220709 04:32:17, James Redding WA9VEZ via groups.io wrote:

Only one place to avoid signal leakage that junk connectors, cheap coax (bad shielding), poor connections (twisted wires), bi-metallic junctions (ersatze diodes), cause. The filter needs to be on the input connector of the SDR without any adapters. 

Would also suggest that the filter needs to have a zero pole at DC so that any static charge can't get into the SDR front end and do damage. The DC shunt is to avoid the chance that a static charge caused by wind driven "dust" doesn't punch thru input capacitors and reach semiconductors. Momentarily shorting the input connector to discharge any accumulated charge also applies to VNA's.

--
WA9VEZ / Jim
N 39.1766  W 86.2693
Ham since 1962 /Radio fanatic since 1952


Re: SDRC and Airspy R2

jdow
 


On 20220709 03:46:01, David J Taylor via groups.io wrote:
On 08/07/2022 22:00, George Stein - NJ3H via groups.io wrote:
Thanks Simon.

Never could clear up the hiss on the R2.  The HF+ Discovery sure does a much
better job than the R2, both on SDRC and SDR#.

I will say I am under impressed with the R2.

Regards,
George

George,

You could try running the Airspy R2 at the 2.5 Msps rate.  It /might/ be a SUB
issue.

David
GM8ARV


And select the packing option. That reduces the load on USB by about 1/3.

{^_^}


Re: Ettus USRP N200 compatibility #sdrconsolev3 #ettus

Larry Dighera
 

Any progress on this?



On Thu, 30 Jun 2022 10:27:39 +0000, "Simon Brown" <simon@...>
wrote:

Hi,

I've made a mental note to look at this early next week. I have a B200 which should be good enough for testing. I'm sure it'll work...

Simon Brown
https://g4eli.com
https://sdr-radio.com

________________________________
From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> on behalf of Erik M0MWF via groups.io <erik@...>
Sent: 29 June 2022 06:08
To: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io>
Subject: Re: [SDR-Radio] Ettus USRP N200 compatibility #sdrconsolev3 #ettus

Hi Simon,

I hope I don't sound like I'm complaining, but have you had any further time to look into USRP Tx capability?

Am very excited at the prospect with your otherwise wonderful s/w.

Regards,

Erik.


Re: SDRC and Airspy R2

Conrad, PA5Y
 

According to the user manual with the preamp and noise reduction on the MDS at 91.1MHz is -138dBm in 500Hz, which equates to -165dBm/Hz. This is a 9dB noise figure and is probably 3-6dB worse because the NR makes things appear better than they are. If you add 2.5dB to that noise figure you can see that an LNA will be of great benefit.

 

I suggest that a system noise figure of around 2-3dB is optimum for Band II DXing.

 

Regards

 

Conrad PA5Y

 

 

 

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Simon Brown via groups.io
Sent: 09 July 2022 17:29
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] SDRC and Airspy R2

 

Hi,

 

What's the S3 noise figure on Band II ? I have maybe 2dB loss in the 25m RG6, so am wondering what the total NF is.


From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> on behalf of Conrad, PA5Y via groups.io <g0ruz@...>
Sent: 09 July 2022 16:06
To: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io>
Subject: Re: [SDR-Radio] SDRC and Airspy R2

 

BTW I put the BPF before the LNA to help protect it from 144MHz EME high power. I am not suggesting that a PGA103+ will saturate from normal Band II situations. However, it has a little bit too much gain, so a good filter and an attenuator does no harm. The S3 really is excellent. Just like you said 😊

 

73

 

Conrad PA5Y

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Conrad, PA5Y via groups.io
Sent: 09 July 2022 17:01
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] SDRC and Airspy R2

 

Hello Simon, I have done a noise analysis and you WILL benefit from an LNA. I have a PGA103+ preceded by a band pass filter and it seems to work very well. However, I am still waiting for a bigger antenna. I ordered an OPTDES which never arrived. So, I will ask a few of the local Band II DXers for an alternative.

 

73

 

Conrad PA5Y

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Simon Brown via groups.io
Sent: 09 July 2022 13:22
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] SDRC and Airspy R2

 

FWIW,

 

The ELAD S3 is the best Band II receiver I have. Am thinking about a preamp on the mast for those very weak stations - if I get close to receiving weak signals from across the pond (USA, Canada).


From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> on behalf of George Stein - NJ3H via groups.io <nj3h@...>
Sent: 09 July 2022 08:08
To: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io>
Subject: Re: [SDR-Radio] SDRC and Airspy R2

 

Simon and others,

 

I have attached 3 pictures all with Console running.

 

Elad S2,

Airspy R2

RSPdx

 

 

The RSPdx is the only on of these three that has a decent signal. Running uno is fine also.

 

It is the other two that are causing problems.  The native software yields the same lousy signals.  There is a lot of noise on these two receivers for the station in question. I have fiddles with the R2 slide controls in both Sharp and Console. The Elad appears not to have any RF gain capability.

 

The frequency I am using for this exercise is 98.9, 92 watts, 25 km away.  I am using the same antenna for all three radios.  The antenna is pictured in an attachment. Same feed line to all three radios. My HF+ Discovery works fine also.

 

As I said in a previous message, the Elad S2 is the one that really puzzles me.  I would have expected it to come out the best (based only on price, that is).

 

Anyway, please let me know if more information is needed.

 

Thanks for looking into this.

 

Regards,

George

 

 

 

On Friday, July 8, 2022 at 11:38:57 PM PDT, jdow <jdow@...> wrote:

 

 

Frequency?

{o.o}

On 20220708 14:47:30, George Stein - NJ3H via groups.io wrote:

92 watts not 25.

On Fri, Jul 8, 2022 at 2:24 PM, George Stein -  NJ3H via groups.io

<nj3h@...> wrote:

Further to my last message.  The station in question is 25 km away and running a mere 25 watts. 

Using SDR Console:

With the Elad S2 and and the Airspy R2, the reception was very noisy.

With the Airspy HF+ Discovery and the RSPdx, the signal was full quieting. With the edge going to the HF+ Discovery.

This was not a scientific test, just a casual observation. The only thing I am surprised about was the Elad S2 performance.

I then used the native software for each device and had the same results.

Regards and YMMV,
George


--

- + - + -

Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.


--

- + - + -

Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.


Re: SDRC and Airspy R2

Simon Brown
 

Hi,

What's the S3 noise figure on Band II ? I have maybe 2dB loss in the 25m RG6, so am wondering what the total NF is.

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> on behalf of Conrad, PA5Y via groups.io <g0ruz@...>
Sent: 09 July 2022 16:06
To: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io>
Subject: Re: [SDR-Radio] SDRC and Airspy R2
 

BTW I put the BPF before the LNA to help protect it from 144MHz EME high power. I am not suggesting that a PGA103+ will saturate from normal Band II situations. However, it has a little bit too much gain, so a good filter and an attenuator does no harm. The S3 really is excellent. Just like you said 😊

 

73

 

Conrad PA5Y

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Conrad, PA5Y via groups.io
Sent: 09 July 2022 17:01
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] SDRC and Airspy R2

 

Hello Simon, I have done a noise analysis and you WILL benefit from an LNA. I have a PGA103+ preceded by a band pass filter and it seems to work very well. However, I am still waiting for a bigger antenna. I ordered an OPTDES which never arrived. So, I will ask a few of the local Band II DXers for an alternative.

 

73

 

Conrad PA5Y

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Simon Brown via groups.io
Sent: 09 July 2022 13:22
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] SDRC and Airspy R2

 

FWIW,

 

The ELAD S3 is the best Band II receiver I have. Am thinking about a preamp on the mast for those very weak stations - if I get close to receiving weak signals from across the pond (USA, Canada).


From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> on behalf of George Stein - NJ3H via groups.io <nj3h@...>
Sent: 09 July 2022 08:08
To: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io>
Subject: Re: [SDR-Radio] SDRC and Airspy R2

 

Simon and others,

 

I have attached 3 pictures all with Console running.

 

Elad S2,

Airspy R2

RSPdx

 

 

The RSPdx is the only on of these three that has a decent signal. Running uno is fine also.

 

It is the other two that are causing problems.  The native software yields the same lousy signals.  There is a lot of noise on these two receivers for the station in question. I have fiddles with the R2 slide controls in both Sharp and Console. The Elad appears not to have any RF gain capability.

 

The frequency I am using for this exercise is 98.9, 92 watts, 25 km away.  I am using the same antenna for all three radios.  The antenna is pictured in an attachment. Same feed line to all three radios. My HF+ Discovery works fine also.

 

As I said in a previous message, the Elad S2 is the one that really puzzles me.  I would have expected it to come out the best (based only on price, that is).

 

Anyway, please let me know if more information is needed.

 

Thanks for looking into this.

 

Regards,

George

 

 

 

On Friday, July 8, 2022 at 11:38:57 PM PDT, jdow <jdow@...> wrote:

 

 

Frequency?

{o.o}

On 20220708 14:47:30, George Stein - NJ3H via groups.io wrote:

92 watts not 25.

On Fri, Jul 8, 2022 at 2:24 PM, George Stein -  NJ3H via groups.io

<nj3h@...> wrote:

Further to my last message.  The station in question is 25 km away and running a mere 25 watts. 

Using SDR Console:

With the Elad S2 and and the Airspy R2, the reception was very noisy.

With the Airspy HF+ Discovery and the RSPdx, the signal was full quieting. With the edge going to the HF+ Discovery.

This was not a scientific test, just a casual observation. The only thing I am surprised about was the Elad S2 performance.

I then used the native software for each device and had the same results.

Regards and YMMV,
George


--

- + - + -

Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.


--
- + - + -
Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.


Re: SDRC and Airspy R2

Conrad, PA5Y
 

BTW I put the BPF before the LNA to help protect it from 144MHz EME high power. I am not suggesting that a PGA103+ will saturate from normal Band II situations. However, it has a little bit too much gain, so a good filter and an attenuator does no harm. The S3 really is excellent. Just like you said 😊

 

73

 

Conrad PA5Y

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Conrad, PA5Y via groups.io
Sent: 09 July 2022 17:01
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] SDRC and Airspy R2

 

Hello Simon, I have done a noise analysis and you WILL benefit from an LNA. I have a PGA103+ preceded by a band pass filter and it seems to work very well. However, I am still waiting for a bigger antenna. I ordered an OPTDES which never arrived. So, I will ask a few of the local Band II DXers for an alternative.

 

73

 

Conrad PA5Y

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Simon Brown via groups.io
Sent: 09 July 2022 13:22
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] SDRC and Airspy R2

 

FWIW,

 

The ELAD S3 is the best Band II receiver I have. Am thinking about a preamp on the mast for those very weak stations - if I get close to receiving weak signals from across the pond (USA, Canada).


From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> on behalf of George Stein - NJ3H via groups.io <nj3h@...>
Sent: 09 July 2022 08:08
To: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io>
Subject: Re: [SDR-Radio] SDRC and Airspy R2

 

Simon and others,

 

I have attached 3 pictures all with Console running.

 

Elad S2,

Airspy R2

RSPdx

 

 

The RSPdx is the only on of these three that has a decent signal. Running uno is fine also.

 

It is the other two that are causing problems.  The native software yields the same lousy signals.  There is a lot of noise on these two receivers for the station in question. I have fiddles with the R2 slide controls in both Sharp and Console. The Elad appears not to have any RF gain capability.

 

The frequency I am using for this exercise is 98.9, 92 watts, 25 km away.  I am using the same antenna for all three radios.  The antenna is pictured in an attachment. Same feed line to all three radios. My HF+ Discovery works fine also.

 

As I said in a previous message, the Elad S2 is the one that really puzzles me.  I would have expected it to come out the best (based only on price, that is).

 

Anyway, please let me know if more information is needed.

 

Thanks for looking into this.

 

Regards,

George

 

 

 

On Friday, July 8, 2022 at 11:38:57 PM PDT, jdow <jdow@...> wrote:

 

 

Frequency?

{o.o}

On 20220708 14:47:30, George Stein - NJ3H via groups.io wrote:

92 watts not 25.

On Fri, Jul 8, 2022 at 2:24 PM, George Stein -  NJ3H via groups.io

<nj3h@...> wrote:

Further to my last message.  The station in question is 25 km away and running a mere 25 watts. 

Using SDR Console:

With the Elad S2 and and the Airspy R2, the reception was very noisy.

With the Airspy HF+ Discovery and the RSPdx, the signal was full quieting. With the edge going to the HF+ Discovery.

This was not a scientific test, just a casual observation. The only thing I am surprised about was the Elad S2 performance.

I then used the native software for each device and had the same results.

Regards and YMMV,
George


--

- + - + -

Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.


Re: Mystery mode

Ken Sejkora
 

Thank you, Gary.  The signal is not there all the time; it was there yesterday, Fri:08-Jul around 11:30 UTC, but wasn’t there several times when I checked this morning, Sat:09-Jul.  As stated in my original post, I usually notice it when I tune into WWV at 15 MHz, or when I’m listening to the upper part of the 20-meter band and see the blips in the waterfall above 14.5 MHz.  Given the frequency, I don’t believe it to be local to New England (Kriss up in NH often sees it as well), and is likely propagation from somewhere more distant, although CHU on 14670 kHz was coming in when I took the screenshot yesterday.  Next time I notice it, I’ll check what regions are ‘skipping’ in on 20-meters, and also check WWV and other commercial stations to get a sense of propagation while I’m seeing the mystery signal.

 

If it is some type of frequency-hopping communication mode, I’m impressed that it is spanning a frequency range of about 700 kHz.  That’s pretty big at HF frequencies, but maybe not so up in the VHF and UHF bands.

 

By the way, my monitoring here is with SDR Console, Airspy HF+ Discovery, fed from a random longwire coupled through a 9:1 unun.

 

Thanks again.  Have a great weekend.

 

Ken

 

From: GARY W RUSSELL
Sent: Saturday, July 9, 2022 09:46 AM
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Mystery mode

 

After enlarging the screen shot I see what you are talking about. I’ve actually been monitoring 14 MHz lately and have never noticed that phenomenon before here in Central, IL. I am using  SDR Console, Airspy HF+Discovery and a Wellbrook Loop antenna. I will watch for it though,
Gary

 


Re: SDRC and Airspy R2

Conrad, PA5Y
 

Hello Simon, I have done a noise analysis and you WILL benefit from an LNA. I have a PGA103+ preceded by a band pass filter and it seems to work very well. However, I am still waiting for a bigger antenna. I ordered an OPTDES which never arrived. So, I will ask a few of the local Band II DXers for an alternative.

 

73

 

Conrad PA5Y

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Simon Brown via groups.io
Sent: 09 July 2022 13:22
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] SDRC and Airspy R2

 

FWIW,

 

The ELAD S3 is the best Band II receiver I have. Am thinking about a preamp on the mast for those very weak stations - if I get close to receiving weak signals from across the pond (USA, Canada).


From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> on behalf of George Stein - NJ3H via groups.io <nj3h@...>
Sent: 09 July 2022 08:08
To: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io>
Subject: Re: [SDR-Radio] SDRC and Airspy R2

 

Simon and others,

 

I have attached 3 pictures all with Console running.

 

Elad S2,

Airspy R2

RSPdx

 

 

The RSPdx is the only on of these three that has a decent signal. Running uno is fine also.

 

It is the other two that are causing problems.  The native software yields the same lousy signals.  There is a lot of noise on these two receivers for the station in question. I have fiddles with the R2 slide controls in both Sharp and Console. The Elad appears not to have any RF gain capability.

 

The frequency I am using for this exercise is 98.9, 92 watts, 25 km away.  I am using the same antenna for all three radios.  The antenna is pictured in an attachment. Same feed line to all three radios. My HF+ Discovery works fine also.

 

As I said in a previous message, the Elad S2 is the one that really puzzles me.  I would have expected it to come out the best (based only on price, that is).

 

Anyway, please let me know if more information is needed.

 

Thanks for looking into this.

 

Regards,

George

 

 

 

On Friday, July 8, 2022 at 11:38:57 PM PDT, jdow <jdow@...> wrote:

 

 

Frequency?

{o.o}

On 20220708 14:47:30, George Stein - NJ3H via groups.io wrote:

92 watts not 25.

On Fri, Jul 8, 2022 at 2:24 PM, George Stein -  NJ3H via groups.io

<nj3h@...> wrote:

Further to my last message.  The station in question is 25 km away and running a mere 25 watts. 

Using SDR Console:

With the Elad S2 and and the Airspy R2, the reception was very noisy.

With the Airspy HF+ Discovery and the RSPdx, the signal was full quieting. With the edge going to the HF+ Discovery.

This was not a scientific test, just a casual observation. The only thing I am surprised about was the Elad S2 performance.

I then used the native software for each device and had the same results.

Regards and YMMV,
George


--

- + - + -

Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.


Re: Bye-Bye 4m, Hello Band II

Curt Faulk
 

I pay for an annual Microsoft 365 Family subscription ($70 US annually). With it, you get 5TB of OneDrive storage albeit spread across 5 different OneDrive accounts of 1 TB each. I think it is well worth it.

From my recent renewal notice:

Your 1 year subscription to Microsoft 365 Family has been renewed. Your subscription was successfully renewed on Monday, July 04, 2022. On your next renewal date, Tuesday, July 04, 2023, USD 69.99 plus applicable taxes will be charged.


Re: Off-topic from SDRC

Curt Faulk
 

George, couldn't you just set up a server using SDR# Spyserver or the excellent SDR Console Server? It seems to me that would be the best option and it's not difficult to do. Kriss, KA1GJU, has written some excellent documentation on how to do it in SDR Console. I'm sure you can find his setup guide by searching this list. It seems to me that a server is the way to go and would be far preferable to a remote desktop session unless you're just planning to listen using your smartphone.


Re: Mystery mode

GARY W RUSSELL
 

After enlarging the screen shot I see what you are talking about. I’ve actually been monitoring 14 MHz lately and have never noticed that phenomenon before here in Central, IL. I am using  SDR Console, Airspy HF+Discovery and a Wellbrook Loop antenna. I will watch for it though,
Gary


Re: Mystery mode

Ken Sejkora
 

I agree with Kriss.  I’m not sure if ‘random’ is the proper term to use regarding the ‘pips’, but the fact that they are  very short-duration intermittent and jump around between discrete frequencies suggests to me that they are not interference.  My experience with ‘interference’ lines is that they tend to be either constant or perhaps periodic at some repetitive sequence.  Perhaps I’ll try recording the ‘pips’ in CW mode on one given frequency and try to analyze the duration and see if there is any identifiable modulation in the short period.

 

Thanks to everyone that has offered their suggestions.  Have a great weekend. 73

 

Ken -- WBØOCV

 

From: Kriss Kliegle KA1GJU
Sent: Saturday, July 9, 2022 07:43 AM
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Mystery mode

 

I've seen them too from southeast NH. The 'pips' are too random for QRM, I was thinking spread spectrum comms myself.
It's hard to actually listen to them, due to not appearing on the same frequency over short periods of time.

73 Kriss KA1GJU

 


Re: Mystery mode

Kriss Kliegle KA1GJU
 

I've seen them too from southeast NH. The 'pips' are too random for QRM, I was thinking spread spectrum comms myself.
It's hard to actually listen to them, due to not appearing on the same frequency over short periods of time.

73 Kriss KA1GJU


Re: Mystery mode

David L. Wilson
 

I should add that the specks that were being asked about look like interference to me.


Re: Optimal RF filter placement/location

James Redding WA9VEZ
 

Only one place to avoid signal leakage that junk connectors, cheap coax (bad shielding), poor connections (twisted wires), bi-metallic junctions (ersatze diodes), cause. The filter needs to be on the input connector of the SDR without any adapters. 

Would also suggest that the filter needs to have a zero pole at DC so that any static charge can't get into the SDR front end and do damage. The DC shunt is to avoid the chance that a static charge caused by wind driven "dust" doesn't punch thru input capacitors and reach semiconductors. Momentarily shorting the input connector to discharge any accumulated charge also applies to VNA's.

--
WA9VEZ / Jim
N 39.1766  W 86.2693
Ham since 1962 /Radio fanatic since 1952


Re: Mystery mode

David L. Wilson
 

I am puzzle by the waterfall display on SIGIDWIKI although the audio file there is SUPERDARN.  I have visited 2 sites here in Virginia.  See attached write-up from my visits.


Re: SDRC and Airspy R2

Simon Brown
 

FWIW,

The ELAD S3 is the best Band II receiver I have. Am thinking about a preamp on the mast for those very weak stations - if I get close to receiving weak signals from across the pond (USA, Canada).

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> on behalf of George Stein - NJ3H via groups.io <nj3h@...>
Sent: 09 July 2022 08:08
To: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io>
Subject: Re: [SDR-Radio] SDRC and Airspy R2
 
Simon and others,

I have attached 3 pictures all with Console running.

Elad S2,
Airspy R2
RSPdx


The RSPdx is the only on of these three that has a decent signal. Running uno is fine also.

It is the other two that are causing problems.  The native software yields the same lousy signals.  There is a lot of noise on these two receivers for the station in question. I have fiddles with the R2 slide controls in both Sharp and Console. The Elad appears not to have any RF gain capability.

The frequency I am using for this exercise is 98.9, 92 watts, 25 km away.  I am using the same antenna for all three radios.  The antenna is pictured in an attachment. Same feed line to all three radios. My HF+ Discovery works fine also.

As I said in a previous message, the Elad S2 is the one that really puzzles me.  I would have expected it to come out the best (based only on price, that is).

Anyway, please let me know if more information is needed.

Thanks for looking into this.

Regards,
George



On Friday, July 8, 2022 at 11:38:57 PM PDT, jdow <jdow@...> wrote:


Frequency?

{o.o}

On 20220708 14:47:30, George Stein - NJ3H via groups.io wrote:
92 watts not 25.


On Fri, Jul 8, 2022 at 2:24 PM, George Stein -  NJ3H via groups.io
<nj3h@...> wrote:
Further to my last message.  The station in question is 25 km away and running a mere 25 watts. 

Using SDR Console:

With the Elad S2 and and the Airspy R2, the reception was very noisy.

With the Airspy HF+ Discovery and the RSPdx, the signal was full quieting. With the edge going to the HF+ Discovery.

This was not a scientific test, just a casual observation. The only thing I am surprised about was the Elad S2 performance.

I then used the native software for each device and had the same results.

Regards and YMMV,
George

--
- + - + -
Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.


Re: Mystery mode

Ken Sejkora
 

Thanks Gary.  I wasn’t referring to the ‘wavy’ signal in the middle of the spectrum from 14750 to 14800 kHz, but rather the “speckling” that occurs throughout the entire spectrum which are very short in duration and occur on multiple discrete frequencies as indicated with the short-duration blips in vertical columns spread 6 to 10 kHz apart.

 

I was aware of the Signal Identification Wiki, and have had it bookmarked for several years now.  Thanks for sharing it with the rest fo the group.

 

Ken -- WBØOCV

 

From: GARY W RUSSELL
Sent: Friday, July 8, 2022 03:14 PM
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Mystery mode

 

It looks like SuperDarn (Super Dual Auroral Radar Network) which is used for scientific research.  It is also found near 11500 and other places in HF radio spectrum.  There is an example on the Sigidwiki:

Radar - Signal Identification Wiki (sigidwiki.com)

Gary