Date   

Re: Earths Doppler

Lance Collister, W7GJ
 

Absolutely NOT! Those of us who work EME know full well that the signals are doppler shifted UP when we are rotating TOWARD the moon (moonrise) and doppler shifted DOWN when we are rotating AWAY from the moon (moonset). The same is true for bouncing signals off any meteors, airplanes, satellites, northern lights, or anything else that is moving! GL and VY 73, Lance

On 2/28/2021 22:29:09, James Brown wrote:

So you agree that the Doppler shift from the Earth’s rotation is always down – right?
or are we still talking past each other.

Â

*From:* main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> *On Behalf Of *jdow
*Sent:* Sunday, February 28, 2021 13:57
*To:* main@SDR-Radio.groups.io
*Subject:* Re: [SDR-Radio] Earths Doppler

Â

Terminology problems are bumping around here.

The absolute Doppler shift is higher if the emitter is approaching you and lower if it is receding from you. As long as constant motion is involved the change in Doppler shift will tend downwards from above normal to below normal as the emitter's relative vector to the observer changes. So I still take exception to your aphorism. "The change in Doppler shift is always down in frequency" is more accurate than "Doppler shift is always down in frequency".

{^_^}


On 20210228 06:46:10, James Brown wrote:

Check this out and tell me what you think
https://tinyurl.com/ry6n6w67 <https://tinyurl.com/ry6n6w67>
Regards…….. Jim

Â

*From:* main@SDR-Radio.groups.io <mailto:main@SDR-Radio.groups.io>
<main@SDR-Radio.groups.io> <mailto:main@SDR-Radio.groups.io> *On Behalf Of *jdow
*Sent:* Saturday, February 27, 2021 21:35
*To:* main@SDR-Radio.groups.io <mailto:main@SDR-Radio.groups.io>
*Subject:* Re: [SDR-Radio] Pluto Pluto+ minimum tuning

Â

Earth's rotational Doppler is as often up as down. Earth's orbital Doppler
should also be up or down. They should be easily separable on long term
observation. The former changes faster than the latter.

How do you get "Doppler shift is always down in frequency?"

{^_^}


On 20210227 21:26:27, James Brown wrote:

It took me a long time and some advice from experts but I finally got it
running.

I know the pointing angle of my antenna, it tracks whatever target it is
set to, so with a bit of Trig I calculate the fall in frequency because of
the Earth’s rotation at that angle, second by second. When the sum of the
change reaches 1 Hz I move the receiver frequency down by 1 Hz.

Each 20 kHz chunk of spectrum gets scanned usually 10,000 times and a
buffer is built from these scans. At the end of 10,000 scans I average each
of the FFT bins and then look for average bins that pop up from their
neighboring bins 5 on each side.  No hits – I move up band to the next
20,000 kHz chunk. If hit – I stay on this frequency and repeat five more
time. All data is saved to my server and can be viewed here:
https://tinyurl.com/2jawwc83 <https://tinyurl.com/2jawwc83>

A complete scan of the 100 MHz wide Waterhole at this rate will take
somewhere on the order of 6 million hours.

p.s. Did you know that Doppler shift is always down in frequency?





Â

*From:* main@SDR-Radio.groups.io <mailto:main@SDR-Radio.groups.io>
<main@SDR-Radio.groups.io> <mailto:main@SDR-Radio.groups.io> *On Behalf Of
*Siegfried Jackstien
*Sent:* Saturday, February 27, 2021 20:07
*To:* main@SDR-Radio.groups.io <mailto:main@SDR-Radio.groups.io>
*Subject:* Re: [SDR-Radio] Pluto Pluto+ minimum tuning

Â

doppler effect is mturn of the earth ... move of the earth, position of
moon and sun ... etc etc

difficult to calculate all that

we have the qo100 sat ... and it drifts around 40hz up down every day (like
the tide in the ocean does)

and ... from earth ist stationary (more or less) ... only moon and sun in
that system moves

now add turning earth ... and move of earth in space ... and different view
angle of antenna (az and el) ... how do you calculate that??

dg9bfc sigi

Am 27.02.2021 um 21:37 schrieb James Brown:

Thanks for the question Roy.

The technique I use to discriminate terrestrial signals from
 Extraterrestrial ones makes use of the fact that signals coming in
from outside the Earth will be shifted down in frequency do to the
Doppler effect from the rotation of the Earth. Carl Sagan outlined this
technique in a book “Communication with Extraterrestrial
Intelligenceâ€&#65533; back in 1971.

So if you look at a waterfall of the same 20 kHz chuck of the spectrum
over a long period of time, say half and hour, all the local signals
will be straight up and down lines. The extraterrestrial ones will
curve down in frequency over that time. So the trick is to sort the two
types.

What I do is chirp the receiver down in step with the calculated Earth
rotational Doppler, which is dependent on the antenna pointing angle.
Right now I see that my receiver is chirping down at 0.112 Hz/Sec. That
way all the local signals in the waterfall appear to curve up and the
Extraterrestrial ones stay in a straight line. This make the software
**much** easier. Then I search through the buffer for vertical lines
rather than curved ones. It does depend on a stable receiver for sure.

That’s the first order detection filter that I use.

Â

Regards….. Jim

*From:* main@SDR-Radio.groups.io <mailto:main@SDR-Radio.groups.io>
<main@SDR-Radio.groups.io> <mailto:main@SDR-Radio.groups.io> *On Behalf
Of *Roy VE7DH
*Sent:* Saturday, February 27, 2021 12:32
*To:* main@SDR-Radio.groups.io <mailto:main@SDR-Radio.groups.io>
*Subject:* Re: [SDR-Radio] Pluto Pluto+ minimum tuning

Â

Hi James,

I took a look at your very interesting web site. One thing I don't
understand is why you need to tune the receiver at all.

Could you not look at the entire 20 khz spectrum in one chunk, as you
say, and then examine each 1 hz portion entirely in software?

This way, there is no tuning requirement, just a stability requirement.

Of, course I may have no idea what I'm talking about...

regards, Roy

Â

Â

--
Lance Collister, W7GJ(ex WA3GPL, WA1JXN, WA1JXN/C6A, ZF2OC/ZF8, E51SIX, 3D2LR, 5W0GJ, E6M, TX5K, KH8/W7GJ, V6M, T8GJ, VK9CGJ, VK9XGJ, C21GJ, CP1GJ, S79GJ, TX7MB)
P.O. Box 73
Frenchtown, MT 59834-0073
USA
TEL: (406) 626-5728
QTH: DN27ub
URL: http://www.bigskyspaces.com/w7gj
Skype: lanceW7GJ
2m DXCC #11 - 6m DXCC #815 - FFMA #7

Interested in 6m EME? Ask me about subscribing to the new Magic Band EME
email group, or just fill in the request box at the bottom of my web
page (above)!


Re: Version 3.0.26 Wobbly audio ?

Peter (G1FXE)
 
Edited

Where are you suggesting I set the CPU to run at full speed ? Not something I have experience of i'm afraid.
Guidance appreciated.

Peter.....


On Sat, Mar 13, 2021 at 09:55 AM, jdow wrote:
That is why I suggested set the CPU to always run at full speed. Throttling is associated with problems solved by popping up a browser, even on an empty page.

{^_^}

On 20210312 22:55:13, Peter (G1FXE) via groups.io wrote:
Jdow, thanks for tips but the issue is with low CPU load the audio problem is present, when CPU load is high no problem. No scope for any special heatsinking on the CPU I'm afraid as the PC is an all inmone.

Bandwidth is already set at the correct level.
--
Peter.....
(G1FXE)

 
--
Peter.....
(G1FXE)


Re: Version 3.0.26 Wobbly audio ?

jdow
 

That is why I suggested set the CPU to always run at full speed. Throttling is associated with problems solved by popping up a browser, even on an empty page.

{^_^}

On 20210312 22:55:13, Peter (G1FXE) via groups.io wrote:
Jdow, thanks for tips but the issue is with low CPU load the audio problem is present, when CPU load is high no problem. No scope for any special heatsinking on the CPU I'm afraid as the PC is an all inmone.

Bandwidth is already set at the correct level.
--
Peter.....
(G1FXE)


Re: Version 3.0.26 Wobbly audio ?

Simon Brown
 

Peter,

 

I’m off out soon. I suggest we get the internal audio working first – so a screenshot using the standard PC’s audio please. You can always make an audio recording, MP3 is OK for this.

 

Can you give me a link to your PC please?

 

Simon Brown, G4ELI

https://www.sdr-radio.com

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Peter (G1FXE) via groups.io
Sent: 13 March 2021 08:33
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Version 3.0.26 Wobbly audio ?

 

Simon,

Playing some more I have found that if I swap to the Motherboard Sound Chipset (Realtek High Definition Audio) the problem goes away however the sound from this card via the internal speakers is horrible !

My default Sound Device (where I experience the problem) is a Behringer UMC204HD connected to some nice Monitor Speakers, this works without issue on all other applications (Thetis, Powersdr, SDR# etc) and would be my preferred setup to use with SDR Console if we can resolve this 'wobbling'/'stuttering' problem.

I have checked that the Behringer is connected to a USB3 port (It is) and played with some of the buffering setting via its control panel, no joy.
Screenshots attached, incl the audio options screen(s) just to demonstrate that for both sound devices are at 'default' presently, tiny change to the problem is I dabble with these settings but still far from acceptable.

מיכה קליין - I'm glad i'm not alone in this problem, I thought increasing the CPU Load as a fix was just something I was imagining !


Thanks all for the time you are taking in helping.
--
Peter.....
(G1FXE)


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


Re: Version 3.0.26 Wobbly audio ?

Peter (G1FXE)
 

Simon,

Playing some more I have found that if I swap to the Motherboard Sound Chipset (Realtek High Definition Audio) the problem goes away however the sound from this card via the internal speakers is horrible !

My default Sound Device (where I experience the problem) is a Behringer UMC204HD connected to some nice Monitor Speakers, this works without issue on all other applications (Thetis, Powersdr, SDR# etc) and would be my preferred setup to use with SDR Console if we can resolve this 'wobbling'/'stuttering' problem.

I have checked that the Behringer is connected to a USB3 port (It is) and played with some of the buffering setting via its control panel, no joy.
Screenshots attached, incl the audio options screen(s) just to demonstrate that for both sound devices are at 'default' presently, tiny change to the problem is I dabble with these settings but still far from acceptable.

מיכה קליין - I'm glad i'm not alone in this problem, I thought increasing the CPU Load as a fix was just something I was imagining !


Thanks all for the time you are taking in helping.
--
Peter.....
(G1FXE)


Re: Version 3.0.26 Wobbly audio ?

Simon Brown
 

Rule #1: Screenshot.

Rule #2: Add as an attachment.

 

Simon Brown, G4ELI

https://www.sdr-radio.com

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of ???? ?????
Sent: 13 March 2021 07:25
To: pkgcruise1@...; main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Version 3.0.26 Wobbly audio ?

 

Hello Peter,

Same issue here. I run sdr-console v. 3.0.22,  laptop with i7 16gb 64bit os, Realtek high definition audio card,  win 7 proffesional.

Only fix I have found is a backgrond youtube window open, preferably with a video running in loop.

This way the problem is gone.

Micha 4z1km

 


ב מרץ 13, 2021 8:55, Peter (G1FXE) via groups.io כתב:

Jdow, thanks for tips but the issue is with low CPU load the audio problem is present, when CPU load is high no problem. No scope for any special heatsinking on the CPU I'm afraid as the PC is an all inmone.

Bandwidth is already set at the correct level.
--
Peter.....
(
G1FXE)


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


Re: Version 3.0.26 Wobbly audio ?

מיכה קליין
 

Hello Peter,
Same issue here. I run sdr-console v. 3.0.22,  laptop with i7 16gb 64bit os, Realtek high definition audio card,  win 7 proffesional.
Only fix I have found is a backgrond youtube window open, preferably with a video running in loop.
This way the problem is gone.
Micha 4z1km
 


ב מרץ 13, 2021 8:55, Peter (G1FXE) via groups.io כתב:
Jdow, thanks for tips but the issue is with low CPU load the audio problem is present, when CPU load is high no problem. No scope for any special heatsinking on the CPU I'm afraid as the PC is an all inmone.

Bandwidth is already set at the correct level.
--
Peter.....
(G1FXE)


Re: Version 3.0.26 Wobbly audio ?

Simon Brown
 

Let’s see a screenshot as an attachment.

 

Simon Brown, G4ELI

https://www.sdr-radio.com

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Peter (G1FXE) via groups.io
Sent: 13 March 2021 06:55
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Version 3.0.26 Wobbly audio ?

 

Jdow, thanks for tips but the issue is with low CPU load the audio problem is present, when CPU load is high no problem. No scope for any special heatsinking on the CPU I'm afraid as the PC is an all inmone.

Bandwidth is already set at the correct level.
--
Peter.....
(G1FXE)


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


Re: Version 3.0.26 Wobbly audio ?

Peter (G1FXE)
 

Jdow, thanks for tips but the issue is with low CPU load the audio problem is present, when CPU load is high no problem. No scope for any special heatsinking on the CPU I'm afraid as the PC is an all inmone.

Bandwidth is already set at the correct level.
--
Peter.....
(G1FXE)


Re: Version 3.0.26 Wobbly audio ?

jdow
 

Another point, with an RTL dongle don't go above 2.4 msps. It starts dropping samples in all the dongles I have had pass through my hands. That gives "wobbly audio."

{o.o}

On 20210312 20:17:23, jdow wrote:
It you modify power settings so that the CPU is running flat out all the time, which requires really good heat sinks, that may get rid of the problem. I'd also look into running the SDRC at a slightly higher priority.

{^_^}

On 20210312 11:31:54, Peter via groups.io wrote:

[Edited Message Follows]

Good evening group.

I've just installed SDR Console V3.0.26 64-Bit with the hope of using it in conjunction with a Pluto (on its way to me) to access QO-100.

But, I have a problem, when familiarising myself with the software using an RTL Dongle and listening to BC-FM the receive audio is very wobbly and occasionally drops out for a ms or two.
I have gone through all of the setup items and the audio buffer settings do make a very slight difference but the 'wobbling' persists.

When researching trying to find answers I did notice though that the more tabs I opened in my browser the better the audio got !
This translates to a higher CPU Load and a Lower Audio Playback Buffer Value, as displayed on the SDR Console taskbar.
Obviously artificially increasing the CPU load is not the real answer.

Any tips or Hints as to where I can look next ?

BTW, My shack PC is a Intel Core i3 with Windows 10 64-Bit and comfortably runs my Anan 100D via Thetis or PowerSDR. Also the RTL_Dongle works perfectly with SDR #.

Thanks,
Peter.....
(G1FXE)



Re: Version 3.0.26 Wobbly audio ?

jdow
 

It you modify power settings so that the CPU is running flat out all the time, which requires really good heat sinks, that may get rid of the problem. I'd also look into running the SDRC at a slightly higher priority.

{^_^}

On 20210312 11:31:54, Peter via groups.io wrote:

[Edited Message Follows]

Good evening group.

I've just installed SDR Console V3.0.26 64-Bit with the hope of using it in conjunction with a Pluto (on its way to me) to access QO-100.

But, I have a problem, when familiarising myself with the software using an RTL Dongle and listening to BC-FM the receive audio is very wobbly and occasionally drops out for a ms or two.
I have gone through all of the setup items and the audio buffer settings do make a very slight difference but the 'wobbling' persists.

When researching trying to find answers I did notice though that the more tabs I opened in my browser the better the audio got !
This translates to a higher CPU Load and a Lower Audio Playback Buffer Value, as displayed on the SDR Console taskbar.
Obviously artificially increasing the CPU load is not the real answer.

Any tips or Hints as to where I can look next ?

BTW, My shack PC is a Intel Core i3 with Windows 10 64-Bit and comfortably runs my Anan 100D via Thetis or PowerSDR. Also the RTL_Dongle works perfectly with SDR #.

Thanks,
Peter.....
(G1FXE)


Re: FT8 checking my signal

jdow
 

Probably. Usual protection is at static discharge energy levels. At one time I had a Gap Titan vertical and my long wire. The Gap Titan could generate volt level signals when I was transmitting at 100 watts on my Pro-II. That may cause damage long term. Although it is just a little above the power used in diode double balanced mixers as the LO. Regardless, with an abundance of caution I draw a mental the line at about 20 mW or 1 Vrms.

Of the receiver is very overloaded on frequency it will generate all manner of strange results. Put in some attenuation until the front end is not overloaded. Then look. Note that the RX-888 is wide open on the front end with no prefiltering to speak of beyond anti-aliasing filters appropriate to its native sample rate.

{^_^}

On 20210312 08:15:15, Radioman ZeroZero wrote:
Hi Jdow,

Can I damage my RX-888 receiver with indoor loop?  It is very overloaded when on the signal.

The transmitter is on another outdoor antenna with ICOM IC-746.
--
Thanks Steve M0ZEH


Version 3.0.26 Wobbly audio ?

Peter (G1FXE)
 
Edited

Good evening group.

I've just installed SDR Console V3.0.26 64-Bit with the hope of using it in conjunction with a Pluto (on its way to me) to access QO-100.

But, I have a problem, when familiarising myself with the software using an RTL Dongle and listening to BC-FM the receive audio is very wobbly and occasionally drops out for a ms or two.
I have gone through all of the setup items and the audio buffer settings do make a very slight difference but the 'wobbling' persists.

When researching trying to find answers I did notice though that the more tabs I opened in my browser the better the audio got !
This translates to a higher CPU Load and a Lower Audio Playback Buffer Value, as displayed on the SDR Console taskbar.
Obviously artificially increasing the CPU load is not the real answer.

Any tips or Hints as to where I can look next ?

BTW, My shack PC is a Intel Core i3 with Windows 10 64-Bit and comfortably runs my Anan 100D via Thetis or PowerSDR. Also the RTL_Dongle works perfectly with SDR #.

Thanks,
Peter.....
(G1FXE)


Re: FT8 checking my signal

Mag loop Simon
 

I do hope thats not your signal!

Not on 1/2 frequency..

As a matter of interest whats the rig? ( ask cos if has 2 antenna sockets and rx out you could use the 888 as a panadapter on the loop too.)

Simon g0zen


Re: FT8 checking my signal

Radioman ZeroZero
 
Edited

Dave,

I think the spurs are noise.
--
Thanks Steve M0ZEH


Re: FT8 checking my signal

Radioman ZeroZero
 

Hi Jdow,

Can I damage my RX-888 receiver with indoor loop?  It is very overloaded when on the signal.

The transmitter is on another outdoor antenna with ICOM IC-746.
--
Thanks Steve M0ZEH


Re: FT8 checking my signal

jdow
 

More to the point, how strong is the desired signal on 20 meters? The receiver could be completely overloaded. But he'd know to check that, right?

{^_-}

On 20210311 09:21:53, Dave Cole wrote:
How many db down are the spurs I see on each side?  I can't make out the scale.

73, and thanks,
Dave (NK7Z)
https://www.nk7z.net
ARRL Volunteer Examiner
ARRL Technical Specialist, RFI
ARRL Asst. Director, NW Division, Technical Resources

On 3/11/21 9:18 AM, jdow wrote:
What are you using as a transmitter? You may have discovered a bug in your Transmitter.
{^_^}

On 20210311 06:57:28, Radioman ZeroZero wrote:
FT8 screenshot of my own transmission taken 1 band down whilst transmitting on 20m.  Its a good way to check your not over modulating!
-- 
Thanks Steve M0ZEH
Screenshot-2021-03-11-144506.jpeg









Re: FT8 checking my signal

Dave (NK7Z)
 

How many db down are the spurs I see on each side? I can't make out the scale.

73, and thanks,
Dave (NK7Z)
https://www.nk7z.net
ARRL Volunteer Examiner
ARRL Technical Specialist, RFI
ARRL Asst. Director, NW Division, Technical Resources

On 3/11/21 9:18 AM, jdow wrote:
What are you using as a transmitter? You may have discovered a bug in your Transmitter.
{^_^}
On 20210311 06:57:28, Radioman ZeroZero wrote:
FT8 screenshot of my own transmission taken 1 band down whilst transmitting on 20m.  Its a good way to check your not over modulating!
--
Thanks Steve M0ZEH
Screenshot-2021-03-11-144506.jpeg


Re: FT8 checking my signal

jdow
 

What are you using as a transmitter? You may have discovered a bug in your Transmitter.
{^_^}

On 20210311 06:57:28, Radioman ZeroZero wrote:
FT8 screenshot of my own transmission taken 1 band down whilst transmitting on 20m.  Its a good way to check your not over modulating!
--
Thanks Steve M0ZEH
Screenshot-2021-03-11-144506.jpeg


FT8 checking my signal

Radioman ZeroZero
 

FT8 screenshot of my own transmission taken 1 band down whilst transmitting on 20m.  Its a good way to check your not over modulating!
--
Thanks Steve M0ZEH

1081 - 1100 of 62530