Date   

Re: Earths Doppler

Tony_AD0VC
 

I woke up this morning and my thoughts wandered to the doppler discussion. I came to the same conclusion as you have described here. There are two uses of the term. An observer "in the wild" with no knowledge of the source, encounters a signal and observes that signal. As the encounter progresses, the observer will always see the departing frequency as lower than the approaching frequency. In that case, all measurements are made relative to the observers reference frame.  But, if we have sufficient knowledge of the source, then we can define the observed frequency relative to the source reference frame (source frequency). In that case the shift is up on the approach and down on the departure. We are describing two different shift quantities but using the term "Doppler shift" for both.

I claim no expertise in the matter and gladly defer to those who do. This is just how I have it sorted.

Tony




From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> on behalf of David L. Wilson via groups.io <dwilson314@...>
Sent: Tuesday, March 2, 2021 7:38 AM
To: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io>
Subject: Re: [SDR-Radio] Earths Doppler
 
Just a comment that people often refer to "doppler" as to how they know a signal is a non-geostationary satellite, i.e., its change in frequency as it passes.  And of course they are indeed referring to the derivative of the frequency but that is what they (essentially most of them) are calling "doppler".  So in reality, "doppler" is used two ways:  (1)  the difference from the transmitted frequency and receive frequency due to relative motion between the transmitter and receiver, and (2)  the changing (derivative) in frequency as a non-geostationary satellite passes over.  In reality, in some (likely most) signal *listening* circles, (2) is the most common use (using more words like "derivative of the frequency" or "changing of frequency" would be too verbose); those people would refer to the difference from the transmitted frequency as the "doppler shift" (and in the Wiki page refered to, they are addressing "doppler shift").  The main point here is that in usagethe word  "doppler" alone is a general (somewhat sloppy) term that can mean different things.  That (unlike doppler shift) is not going to change. :-)


Re: Digital Anyone?

Matthias Bopp
 

Hi Simon,

As the Modem and the GUI are already separated we will check whether we can accomodate your request.

Regards

Matthias


-------- Ursprüngliche Nachricht --------
Von: Simon Brown <simon@...>
Datum: 04.03.21 13:30 (GMT+01:00)
An: main@SDR-Radio.groups.io
Betreff: Re: [SDR-Radio] Digital Anyone?

Or,

Write the modem as a DLL so it can be integrated with other programs? I had thought about writing something like this but didn't have time.

Simon Brown, G4ELI
https://www.sdr-radio.com

-----Original Message-----
From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Matthias Bopp
Sent: 04 March 2021 11:43
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Digital Anyone?

Hi

Good idea.

Maybe also an interface to the hsmodem from AMSAT-DL.

Presently we are using a VAC interface which Is not optimum, an UDP interface would be preferred.

Kind regards

Matthias

www.dd1us.de


-----Ursprüngliche Nachricht-----
Von: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> Im Auftrag von David J Taylor via groups.io
Gesendet: Donnerstag, 4. März 2021 12:01
An: main@SDR-Radio.groups.io
Betreff: Re: [SDR-Radio] Digital Anyone?

On 04/03/2021 10:09, Simon Brown wrote:
> Hi,
>
> Initial modes are: RTTY, Wefax, SITOR-B/Navtex.
>
> Adding more will be easy.
>
> Simon Brown, G4ELI
>
> https://www.sdr-radio.com <https://www.sdr-radio.com/>

Perhaps the various digital voice modes too?  Plug-ins?

David
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Web: https://www.satsignal.eu
Email: david-taylor@...
Twitter: @gm8arv














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Re: Digital Anyone?

Simon Brown
 

Or,

Write the modem as a DLL so it can be integrated with other programs? I had thought about writing something like this but didn't have time.

Simon Brown, G4ELI
https://www.sdr-radio.com

-----Original Message-----
From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Matthias Bopp
Sent: 04 March 2021 11:43
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Digital Anyone?

Hi

Good idea.

Maybe also an interface to the hsmodem from AMSAT-DL.

Presently we are using a VAC interface which Is not optimum, an UDP interface would be preferred.

Kind regards

Matthias

www.dd1us.de


-----Ursprüngliche Nachricht-----
Von: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> Im Auftrag von David J Taylor via groups.io
Gesendet: Donnerstag, 4. März 2021 12:01
An: main@SDR-Radio.groups.io
Betreff: Re: [SDR-Radio] Digital Anyone?

On 04/03/2021 10:09, Simon Brown wrote:
Hi,

Initial modes are: RTTY, Wefax, SITOR-B/Navtex.

Adding more will be easy.

Simon Brown, G4ELI

https://www.sdr-radio.com <https://www.sdr-radio.com/>
Perhaps the various digital voice modes too? Plug-ins?

David
--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@blueyonder.co.uk
Twitter: @gm8arv














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Re: Digital Anyone?

Matthias Bopp
 

Hi

Good idea.

Maybe also an interface to the hsmodem from AMSAT-DL.

Presently we are using a VAC interface which Is not optimum, an UDP interface would be preferred.

Kind regards

Matthias

www.dd1us.de


-----Ursprüngliche Nachricht-----
Von: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> Im Auftrag von David J Taylor via groups.io
Gesendet: Donnerstag, 4. März 2021 12:01
An: main@SDR-Radio.groups.io
Betreff: Re: [SDR-Radio] Digital Anyone?

On 04/03/2021 10:09, Simon Brown wrote:
Hi,

Initial modes are: RTTY, Wefax, SITOR-B/Navtex.

Adding more will be easy.

Simon Brown, G4ELI

https://www.sdr-radio.com <https://www.sdr-radio.com/>
Perhaps the various digital voice modes too? Plug-ins?

David
--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@blueyonder.co.uk
Twitter: @gm8arv


Re: Digital Anyone?

Simon Brown
 

Hi,

They are all plugins (DLLs) with the same functions.

Simon Brown, G4ELI
https://www.sdr-radio.com

-----Original Message-----
From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of David J Taylor via groups.io
Sent: 04 March 2021 11:01
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Digital Anyone?

On 04/03/2021 10:09, Simon Brown wrote:
Hi,

Initial modes are: RTTY, Wefax, SITOR-B/Navtex.

Adding more will be easy.

Simon Brown, G4ELI

https://www.sdr-radio.com <https://www.sdr-radio.com/>
Perhaps the various digital voice modes too? Plug-ins?

David
--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@blueyonder.co.uk
Twitter: @gm8arv









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


Re: Digital Anyone?

bob550
 

Awesome! 


Re: Digital Anyone?

David J Taylor
 

On 04/03/2021 10:09, Simon Brown wrote:
Hi,
Initial modes are: RTTY, Wefax, SITOR-B/Navtex.
Adding more will be easy.
Simon Brown, G4ELI
https://www.sdr-radio.com <https://www.sdr-radio.com/>
Perhaps the various digital voice modes too? Plug-ins?

David
--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@blueyonder.co.uk
Twitter: @gm8arv


Re: Digital Anyone?

Simon Brown
 

Hi,

 

Initial modes are: RTTY, Wefax, SITOR-B/Navtex.

 

Adding more will be easy.

 

Simon Brown, G4ELI

https://www.sdr-radio.com

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of C. van Ravenswaaij
Sent: 04 March 2021 09:11
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Digital Anyone?

 

Hi Simon,

Looks very nice. Do you also have plans to expand the amount of modes?
May I suggest:

FT8
SITOR-A
SITOR-B
ACARS
ARINC 635 (HFDL)
ALE
FAX

Not all at once of course ;-)

73, Cornel


Op 3-3-2021 om 18:56 schreef Simon Brown:

Maybe available in June/July 2021.

 

Simon Brown, G4ELI

https://www.sdr-radio.com

 


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Re: Digital Anyone?

C. van Ravenswaaij
 

Hi Simon,

Looks very nice. Do you also have plans to expand the amount of modes?
May I suggest:

FT8
SITOR-A
SITOR-B
ACARS
ARINC 635 (HFDL)
ALE
FAX

Not all at once of course ;-)

73, Cornel



Op 3-3-2021 om 18:56 schreef Simon Brown:

Maybe available in June/July 2021.

 

Simon Brown, G4ELI

https://www.sdr-radio.com

 


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Re: Digital Anyone?

Winston
 

All in one would be fantastic.


Re: locking the receiver to a stable carrier

Mauno_Ritola
 

Screenshots!

jdow kirjoitti 3.3.2021 klo 23:44:

When it is on the critical frequency for F2 it can do short term (1 second) strange things if you are within ground wave range of the transmitter or have multipath from other sources.

And, locking to WWV(H) is only possible when it is within your front end passband. This rather renders this as a poor return for the work involved.

{^_^}

On 20210303 02:21:27, Mauno_Ritola wrote:

OK, if that can be described as "a surprising amount" of variation, then I agree. And that is the maximum I have noticed, less when no geom. disturbance occuring. I use them for calibrating the receiver for medium wave carrier measurement and have been very satisfied to get better than 1 Hz accuracy there. A cheap method!

:-)

jdow kirjoitti 3.3.2021 klo 12:00:
1 Hz at 10 MHz is quite a lot as I see it. (GPS satellites in the IIa series had synthesizers on board that controlled the frequency in about 2 microHz steps at 10.23 MHz. Now THAT is serious calibration.

Actually that flippancy notwithstanding, there is at least one person out there using SDRs to monitor astronomical the change in Doppler Shift of signals from "out there." He needs serious stability which WWV would not provide during significant portions of the day. GPS based stabilization should be his cuppa.

{^_^}

On 20210303 01:11:46, Mauno_Ritola wrote:

Dear ?,
could you please post an image of showing WWV carrier varying "a surprising amount throughout a day"? I have been using WWV carrier for calibration for a quarter century here 8 000 km away and I haven't yet seen it drift more than ±1 Hz at 15 or 10 MHz. It can get a bit smeared either way for some time, but it is easy to observe that on waterfall and avoid such times, move to a lower fq or check another accurate carriers like for CRI, RRI, BBC etc.

Best regards,

Mauno Ritola
Finland

jdow kirjoitti 3.3.2021 klo 1:05:
The theoretical possibility exists if and only if that carrier is within your current front end's passband. For example, you cannot lock an AirSpy Discovery to WWV while listening to 3.87 MHz AM. But, you could lock an AirSpy Discovery tuned to 10.103 MHz to 10 MHz WWV if WWV is coming through for you at the time. Such a feature has not been implemented. As I see it the potential for this is so limited and HF "standard frequencies" are so unstable it's not worth it. (WWV varies a surprising amount throughout a day once the ionosphere gets through with mangling it.)

{^_^}

On 20210302 11:17:01, Corneliu via groups.io wrote:
There is a special feature in SDR Console which locks the receiver to the digital beacon on the narrow-band transponder.
Is it possible to implement this feature in the HF spectrum, locking the receiver to a stable carrier?

73 de YO4AUL





Re: locking the receiver to a stable carrier

jdow
 

When it is on the critical frequency for F2 it can do short term (1 second) strange things if you are within ground wave range of the transmitter or have multipath from other sources.

And, locking to WWV(H) is only possible when it is within your front end passband. This rather renders this as a poor return for the work involved.

{^_^}

On 20210303 02:21:27, Mauno_Ritola wrote:

OK, if that can be described as "a surprising amount" of variation, then I agree. And that is the maximum I have noticed, less when no geom. disturbance occuring. I use them for calibrating the receiver for medium wave carrier measurement and have been very satisfied to get better than 1 Hz accuracy there. A cheap method!

:-)

jdow kirjoitti 3.3.2021 klo 12:00:
1 Hz at 10 MHz is quite a lot as I see it. (GPS satellites in the IIa series had synthesizers on board that controlled the frequency in about 2 microHz steps at 10.23 MHz. Now THAT is serious calibration.

Actually that flippancy notwithstanding, there is at least one person out there using SDRs to monitor astronomical the change in Doppler Shift of signals from "out there." He needs serious stability which WWV would not provide during significant portions of the day. GPS based stabilization should be his cuppa.

{^_^}

On 20210303 01:11:46, Mauno_Ritola wrote:

Dear ?,
could you please post an image of showing WWV carrier varying "a surprising amount throughout a day"? I have been using WWV carrier for calibration for a quarter century here 8 000 km away and I haven't yet seen it drift more than ±1 Hz at 15 or 10 MHz. It can get a bit smeared either way for some time, but it is easy to observe that on waterfall and avoid such times, move to a lower fq or check another accurate carriers like for CRI, RRI, BBC etc.

Best regards,

Mauno Ritola
Finland

jdow kirjoitti 3.3.2021 klo 1:05:
The theoretical possibility exists if and only if that carrier is within your current front end's passband. For example, you cannot lock an AirSpy Discovery to WWV while listening to 3.87 MHz AM. But, you could lock an AirSpy Discovery tuned to 10.103 MHz to 10 MHz WWV if WWV is coming through for you at the time. Such a feature has not been implemented. As I see it the potential for this is so limited and HF "standard frequencies" are so unstable it's not worth it. (WWV varies a surprising amount throughout a day once the ionosphere gets through with mangling it.)

{^_^}

On 20210302 11:17:01, Corneliu via groups.io wrote:
There is a special feature in SDR Console which locks the receiver to the digital beacon on the narrow-band transponder.
Is it possible to implement this feature in the HF spectrum, locking the receiver to a stable carrier?

73 de YO4AUL





Digital Anyone?

Simon Brown
 

Maybe available in June/July 2021.

 

Simon Brown, G4ELI

https://www.sdr-radio.com

 


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Re: locking the receiver to a stable carrier

Roy VE7DH
 

I had asked this question last year, in relation to 10 Ghz reception with a TVRO type LNB and/or a downconverter chain.

The question was referred to the "maybe, someday" department.

regards, Roy


Re: Earths Doppler

Andrea Dalbagno
 

Many thanks, José 😊
Andrea



Il mer 3 mar 2021, 11:28 jose maria trueba <josemariatrueba@...> ha scritto:
Excellent parallelism,  Andrea!


Re: Earths Doppler

jose maria trueba
 

Excellent parallelism,  Andrea!


Re: locking the receiver to a stable carrier

Mauno_Ritola
 

OK, if that can be described as "a surprising amount" of variation, then I agree. And that is the maximum I have noticed, less when no geom. disturbance occuring. I use them for calibrating the receiver for medium wave carrier measurement and have been very satisfied to get better than 1 Hz accuracy there. A cheap method!

:-)

jdow kirjoitti 3.3.2021 klo 12:00:

1 Hz at 10 MHz is quite a lot as I see it. (GPS satellites in the IIa series had synthesizers on board that controlled the frequency in about 2 microHz steps at 10.23 MHz. Now THAT is serious calibration.

Actually that flippancy notwithstanding, there is at least one person out there using SDRs to monitor astronomical the change in Doppler Shift of signals from "out there." He needs serious stability which WWV would not provide during significant portions of the day. GPS based stabilization should be his cuppa.

{^_^}

On 20210303 01:11:46, Mauno_Ritola wrote:

Dear ?,
could you please post an image of showing WWV carrier varying "a surprising amount throughout a day"? I have been using WWV carrier for calibration for a quarter century here 8 000 km away and I haven't yet seen it drift more than ±1 Hz at 15 or 10 MHz. It can get a bit smeared either way for some time, but it is easy to observe that on waterfall and avoid such times, move to a lower fq or check another accurate carriers like for CRI, RRI, BBC etc.

Best regards,

Mauno Ritola
Finland

jdow kirjoitti 3.3.2021 klo 1:05:
The theoretical possibility exists if and only if that carrier is within your current front end's passband. For example, you cannot lock an AirSpy Discovery to WWV while listening to 3.87 MHz AM. But, you could lock an AirSpy Discovery tuned to 10.103 MHz to 10 MHz WWV if WWV is coming through for you at the time. Such a feature has not been implemented. As I see it the potential for this is so limited and HF "standard frequencies" are so unstable it's not worth it. (WWV varies a surprising amount throughout a day once the ionosphere gets through with mangling it.)

{^_^}

On 20210302 11:17:01, Corneliu via groups.io wrote:
There is a special feature in SDR Console which locks the receiver to the digital beacon on the narrow-band transponder.
Is it possible to implement this feature in the HF spectrum, locking the receiver to a stable carrier?

73 de YO4AUL




Re: locking the receiver to a stable carrier

jdow
 

1 Hz at 10 MHz is quite a lot as I see it. (GPS satellites in the IIa series had synthesizers on board that controlled the frequency in about 2 microHz steps at 10.23 MHz. Now THAT is serious calibration.

Actually that flippancy notwithstanding, there is at least one person out there using SDRs to monitor astronomical the change in Doppler Shift of signals from "out there." He needs serious stability which WWV would not provide during significant portions of the day. GPS based stabilization should be his cuppa.

{^_^}

On 20210303 01:11:46, Mauno_Ritola wrote:

Dear ?,
could you please post an image of showing WWV carrier varying "a surprising amount throughout a day"? I have been using WWV carrier for calibration for a quarter century here 8 000 km away and I haven't yet seen it drift more than ±1 Hz at 15 or 10 MHz. It can get a bit smeared either way for some time, but it is easy to observe that on waterfall and avoid such times, move to a lower fq or check another accurate carriers like for CRI, RRI, BBC etc.

Best regards,

Mauno Ritola
Finland

jdow kirjoitti 3.3.2021 klo 1:05:
The theoretical possibility exists if and only if that carrier is within your current front end's passband. For example, you cannot lock an AirSpy Discovery to WWV while listening to 3.87 MHz AM. But, you could lock an AirSpy Discovery tuned to 10.103 MHz to 10 MHz WWV if WWV is coming through for you at the time. Such a feature has not been implemented. As I see it the potential for this is so limited and HF "standard frequencies" are so unstable it's not worth it. (WWV varies a surprising amount throughout a day once the ionosphere gets through with mangling it.)

{^_^}

On 20210302 11:17:01, Corneliu via groups.io wrote:
There is a special feature in SDR Console which locks the receiver to the digital beacon on the narrow-band transponder.
Is it possible to implement this feature in the HF spectrum, locking the receiver to a stable carrier?

73 de YO4AUL




Re: locking the receiver to a stable carrier

Mauno_Ritola
 

Dear ?,
could you please post an image of showing WWV carrier varying "a surprising amount throughout a day"? I have been using WWV carrier for calibration for a quarter century here 8 000 km away and I haven't yet seen it drift more than ±1 Hz at 15 or 10 MHz. It can get a bit smeared either way for some time, but it is easy to observe that on waterfall and avoid such times, move to a lower fq or check another accurate carriers like for CRI, RRI, BBC etc.

Best regards,

Mauno Ritola
Finland

jdow kirjoitti 3.3.2021 klo 1:05:

The theoretical possibility exists if and only if that carrier is within your current front end's passband. For example, you cannot lock an AirSpy Discovery to WWV while listening to 3.87 MHz AM. But, you could lock an AirSpy Discovery tuned to 10.103 MHz to 10 MHz WWV if WWV is coming through for you at the time. Such a feature has not been implemented. As I see it the potential for this is so limited and HF "standard frequencies" are so unstable it's not worth it. (WWV varies a surprising amount throughout a day once the ionosphere gets through with mangling it.)

{^_^}

On 20210302 11:17:01, Corneliu via groups.io wrote:
There is a special feature in SDR Console which locks the receiver to the digital beacon on the narrow-band transponder.
Is it possible to implement this feature in the HF spectrum, locking the receiver to a stable carrier?

73 de YO4AUL



Re: SDR Console does not open Pluto

jdow
 

Time for some good old "TRACE" debugging with DebugView?

{o.o}

On 20210302 23:35:27, Simon Brown wrote:

Ah,

 

OK – well, this sounds like either USB or a bad DLL on your system.

 

Simon Brown, G4ELI

https://www.sdr-radio.com

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Jacques RAMBAUD
Sent: 03 March 2021 07:15
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] SDR Console does not open Pluto

 

Simon,

As I said if I try to open the Pluto by Select radio or Start  SDR Console freezes

73

Jacques F6BKI

 

Le 03/03/2021 à 05:44, Simon Brown a écrit :

Hi,

 

Show me the logfile *after* you have tried to open Pluto please.

 

Simon Brown, G4ELI

https://www.sdr-radio.com

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Jacques RAMBAUD
Sent: 02 March 2021 22:47
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] SDR Console does not open Pluto

 

Simon,

attached logfile

Merci

73 jacques F6BKI

Le 02/03/2021 à 17:58, Simon Brown a écrit :

Logfile?

 

Simon Brown, G4ELI

https://www.sdr-radio.com

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Jacques RAMBAUD
Sent: 02 March 2021 16:47
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] SDR Console does not open Pluto

 

Hi Bob,

Thank you, tried using the two USB ports no success.

73

Jacques F6BKI

 

 

Le 02/03/2021 à 14:51, Roy VE7DH a écrit :

Are you using both usb ports on the Pluto? You need to plug in both ports because, quick frankly, the usb connectors on the Pluto are cheap garbage and the main data connector seems to fail at delivering 5 volts to the Pluto, so you need the second usb port connected to make the whole thing work.

At least that is my experience with more than one Pluto.

regards, Roy


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