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Paul Maxan (microp11)

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Nov 22, 2023, 11:07:50 PM11/22/23
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Hi All,

Happy to have found this group. My name is Paul Maxan, I live in Prince Edward Island, Canada, and as of 2 days ago I was able to capture the Hydrogen line with an off-the-shelf setup. I am so happy. My system is not yet calibrated in any way, and I am not very sure that I interpret correctly what I believe I see. I will attach a small video file, an excel speadsheet with selected data, and a sample of averaged values.

My current setup is as follows:
- Nooelec antenna (the one in the GOES Weather Satellite RTL-SDR Bundle ~15deg +/- 7.5deg), looking straight up
- Nooelec SAWbird+ H1 on bias-t (at the antenna)
- 10m RG58
- RTL-SDR Blog V3 R860 (R820T2)
- SDR# + IF-Average plugin
- Stellarium
- Chronolapse (capture screenshots)
- ffmpeg (make movie from screenshots)
- MS Excel

I have recorded data over 24h+ in 10mins intervals, each sample integrated over 500s. The attached speadsheet has 25h of data, one column per hour. I have percentage normalized the data and calculated the doppler shift. Not very precise as I was more interested to get the sign for the doppler and the range close to papers and images I found, which it did.

I am still all over the place, would like to try to understand the system and calibrate it, or at least understand what I am doing. For example, while I understand "cold" and "hot" I still cannot currently wrap my mind in moving from signal power to Kelvins. Then... trying to get my system through a noise calculator app and see if theory matches reality. So much fun! Or automate the capturing...

I have a motorised 2.5m dish that I can control with Stellarium and at some point I would like to move my experiments there. Maybe by next summer?! Not before I understand what I am doing using the current setup.

Thank you. Happy!

Cheers,
Paul

Alex P

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Nov 23, 2023, 12:47:09 AM11/23/23
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Hello Paul,
Welcome to the Group !

You have all the right equipment and software 
Excel is optimal for comparing data and refining your system.
3 years into this, I still use Excel for reviewing the data.

Consider some of these videos ..

and specifically :

Looking forward to seeing your results.


Best Regards,
Alex KK4VB




b alex pettit jr

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Nov 23, 2023, 5:16:48 AM11/23/23
to 'Alex P' via Society of Amateur Radio Astronomers
Noise Temperature etc.

This is an Excellent Reference for Microwave Info






Paul Maxan (microp11)

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Nov 23, 2023, 3:17:09 PM11/23/23
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Hi all,

This is the data I collected at the time of the measurement a couple of days ago. Please see attached.
Recorded over 24h+ in 10mins intervals, each sample integrated over 500s. The attached speadsheet has 25h of data, one column per hour. I have percentage normalized the data and I believe I have calculated the doppler shift correctly.
I think it would be interesting to refere to this in the future, hopefully with a better understanding.

Cheers,
Paul

data.xlsx
0637.jpg

Captain Anne Flint

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Nov 23, 2023, 3:38:55 PM11/23/23
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Welcome Paul! Please send photos of your setup. Wende 

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<data.xlsx><0637.jpg>

b alex pettit jr

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Nov 23, 2023, 3:46:29 PM11/23/23
to 'Paul Maxan (microp11)' via Society of Amateur Radio Astronomers
Hello Paul,

I converted col J of Your Data  to dB ref to Cold Sky  ( as in my plots )

Inline image


FYI, this shows my Very first data to that obtained 1 year later ..
 
Inline image
Alex




b alex pettit jr

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Nov 23, 2023, 4:03:23 PM11/23/23
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I also purchased the 1.7G GOES antenna ..

There are problems with the 1.7G feed ... #1 the dipole is positioned incorrectly  for 1.42G
This compares its normal 38 cm distance to the dish with shortening it to 35cm

Inline image

 I have spent hundreds of hours reading, testing, documenting,  adjusting .. 
each improvement may be only a few 10ths of a dB, but they Add Up !

Andrew Thornett

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Nov 23, 2023, 4:22:58 PM11/23/23
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Nooelec do now sell a 1.4GHz tuned antenna
Andy


From: 'b alex pettit jr' via Society of Amateur Radio Astronomers <sara...@googlegroups.com>
Sent: Thursday, November 23, 2023 9:03:15 PM
To: 'b alex pettit jr' via Society of Amateur Radio Astronomers <sara...@googlegroups.com>
Subject: Re: [SARA] Re: Happy
 
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Andrew Thornett

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Nov 23, 2023, 4:23:32 PM11/23/23
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......it saves all those hours of adjustment
From: Andrew Thornett <andrew....@googlemail.com>
Sent: Thursday, November 23, 2023 9:22:51 PM
To: sara...@googlegroups.com <sara...@googlegroups.com>

Paul Maxan (microp11)

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Nov 23, 2023, 4:31:27 PM11/23/23
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Thank you so much, this is very useful as I can now verify my own calculations.

b alex pettit jr

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Nov 23, 2023, 4:36:46 PM11/23/23
to 'Andrew Thornett' via Society of Amateur Radio Astronomers
Agreed, the 1.42GHz would have performed much better, but :
Its probably not worth the $$ to purchase another Dipole based feed as they still pick up excessive ground noise.

The next step is a Loop_Feed  &  easy to fab.  Due to the close coupling of the LNA to Loop, This is an efficient design.


Inline image

=============================================================================


On Thursday, November 23, 2023 at 04:23:37 PM EST, 'Andrew Thornett' via Society of Amateur Radio Astronomers <sara...@googlegroups.com> wrote:


......it saves all those hours of adjustment


Paul Maxan (microp11)

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Nov 23, 2023, 4:40:32 PM11/23/23
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Thank you Alex,  this is really nice to know. Much appreciated. Will let you know what the difference is once I get to make this change, as I will.
I understand what Andrew T. mentions below, the off-the-shelf being tuned for GOES.

b alex pettit jr

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Nov 23, 2023, 4:44:48 PM11/23/23
to 'Paul Maxan (microp11)' via Society of Amateur Radio Astronomers
Paul, I did not check  your velocity conversion . the formula is in my presentation ....

( and here )

Inline image


FYI, you might consider 'standardizing' on 4 minute ( 1 degree in RA drift ) data scans . and 512 channels is quite sufficient to resolve the velocity spectrum.

See this post
  Inline image


Alex
=================================================================

b alex pettit jr

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Nov 23, 2023, 5:15:04 PM11/23/23
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" % in POWER "

Paul I'm not sure how you converted the IF_Ave data, but the saved amplitude units are Linear not Power units.

Meaning the conversion equation is 20 * LOG10( value ) and if you did not take that into account, I calculated the data Incorrectly,
and the plot Correctly Converted to dB re Cold Sky would actually be  2x higher (  & more reasonable )

Inline image


Paul Maxan (microp11)

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Nov 23, 2023, 5:29:17 PM11/23/23
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Thank you, I understand my confusion regarding linear vs. power. Will take time to clear things in my mind.

This below I found very helpful for me on understanding the measurement of a signal power in dB:

b alex pettit jr

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Nov 23, 2023, 5:49:30 PM11/23/23
to 'Paul Maxan (microp11)' via Society of Amateur Radio Astronomers
I verified the proper equation by inserting calibrated attenuators and recording the result ..

The "Learning Opportunities" associated with Radio Astronomy are Huge ....

Inline image
Alex

Paul Maxan (microp11)

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Nov 24, 2023, 10:49:54 AM11/24/23
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These are the pictures, just a stock Nooelec antenna (the one in the GOES Weather Satellite RTL-SDR Bundle).
The support was changed long time ago to allow for a more precise positioning while I was using it on GOES.
There is a Nooelec SAWbird+ H1 on bias-t in the red enclosure I found on Amazon. The enclosure is not UV resistant, however it did very well over one winter. I just replaced it with a new one for the new winter.
The enclosure is transparent enough to be able to see at night the LED from the amplifier.

antenna.JPG

Marcus D. Leech

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Nov 24, 2023, 12:49:53 PM11/24/23
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On 22/11/2023 22:51, 'Paul Maxan (microp11)' via Society of Amateur
Paul:

If you ever find yourself in the Ottawa area, let me know, and I can
give you a tour of our observatory.

Cheers
Marcus
http://www.ccera.ca


Captain Anne Flint

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Nov 24, 2023, 1:46:49 PM11/24/23
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Thanks, nice looking setup - Wende 

<antenna.JPG>


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Paul Maxan (microp11)

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Dec 7, 2023, 12:24:29 PM12/7/23
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Hi All,

I have received a 1.4G boom from Nooelec, called Inmarsat boom. I am attaching a comparative picture to the similar one from Nooelec for 1.7G that comes with GOES.
I will hopefully be able to set some comparative tests, this coming weekend.

Cheers,
Paul

inmarsat vs goes boom.JPG

b alex pettit jr

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Dec 7, 2023, 12:36:22 PM12/7/23
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Hello Paul,

And for comparison, here are photos of the 1.7G and 2.4G boom&feeds.
Inline image


Alex

Andrew Thornett

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Dec 7, 2023, 12:41:35 PM12/7/23
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Yes that is the same one they send with the 1.4GHz mesh dish. The dosh in that kit is also slightly larger than the one in 1.7GHz kit but I doubt that matters too much.
How much did they charge you for 1.4GHz boom and waveguide?
Andy


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Sent: Thursday, December 7, 2023 5:35:57 PM
To: 'Paul Maxan (microp11)' via Society of Amateur Radio Astronomers <sara...@googlegroups.com>

Subject: Re: [SARA] Re: Happy
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Paul Maxan (microp11)

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Dec 8, 2023, 4:05:25 PM12/8/23
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Hi Andy,

I got the 1.4Ghz boom as part of a kit so I don't have a price.
I am not sure if Nooelec sells it separately, however it would be worth asking for sure. I will ask as well.

Cheers,
Paul

Paul Maxan (microp11)

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Dec 8, 2023, 4:07:27 PM12/8/23
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I will measure the 1.4GHz boom as well, although it would make sense that the dipole (or whatever is inside the black box) is different too, as it is larger than the 1.7Ghz one.

Paul Maxan (microp11)

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Dec 22, 2023, 4:54:16 PM12/22/23
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Hi All,

A bit closer to cleaning up my signals:  https://x.com/microp11sat/status/1738314140198875212?s=20
This is the pre-processed one (in blue) and the processed one (in orange): https://x.com/microp11sat/status/1738313588689805795?s=20.
Captured with the 1.7G boom on the Nooelec antenna, same as the original test, except using https://wvurail.org/dspira-lessons/ DSPIRA instead of SDR# and plugins.
I did not move yet to the 1.4G boom as I was more interested in cleaning what I have received already.
The system is still not calibrated, I hope that the distinction can be made by looking at the signal itself (I would expect more definition I guess) using a better calibrated antenna.

Cheers,
Paul

b alex pettit jr

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Dec 22, 2023, 5:21:43 PM12/22/23
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Hello Paul,

Excellent Data !

While comparing configurations, you want to keep the data in power or convert to dB ref to Cold Sky.
Pick some convenient reference RA/Dec and use the difference between Cold Sky & Max Signal as an indicator of performance.
( signal strength )
 
Inline image

You can also calculate RMS Noise vs Pk Signal
Inline image



Alex


Andrew Thornett

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Dec 23, 2023, 3:52:31 AM12/23/23
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That's excellent and shows the 1.7GHz boom can still very effectively.be used to collect hydrogen data sp perhaps the 1.4GHz boom on Nooelwc mesh antenna really isnt necessary,  especially as it costs lot more.

I wonder - does this reflect other people's experience? How important is it to tune the antenna close to 1.4GHz rather then 1.7GHz, eg with horn antenna or corner antennae or yagis or other dishes?

Andy



From: 'b alex pettit jr' via Society of Amateur Radio Astronomers <sara...@googlegroups.com>
Sent: Friday, December 22, 2023 10:21:35 PM

To: 'Paul Maxan (microp11)' via Society of Amateur Radio Astronomers <sara...@googlegroups.com>
Subject: Re: [SARA] Re: Happy
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b alex pettit jr

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Dec 23, 2023, 7:57:07 AM12/23/23
to 'Andrew Thornett' via Society of Amateur Radio Astronomers
They are identically priced.
Inline image




Andrew Thornett

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Dec 23, 2023, 9:18:24 AM12/23/23
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That is interesting means the 1.7GHz has gone up in price I bought mine for £31 and then £100 for the 1.4GHz version - although admittedly I hadn't looked at Amazon for 1.7GHz version since. 
Wind has blown over 1.4GHz mesh twice in recent storm and wide guide looking rather bent! Hopefully I can straighten it out........
Andy 


From: 'b alex pettit jr' via Society of Amateur Radio Astronomers <sara...@googlegroups.com>
Sent: Saturday, December 23, 2023 12:57:01 PM
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Subject: Re: [SARA] Re: Happy
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Paul Maxan (microp11)

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Dec 23, 2023, 12:39:56 PM12/23/23
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Hi Alex,

Thank you!

I have added a quick RMS calculation and a max peak to peak on the max point only at this time: 
https://x.com/microp11sat/status/1738610892810420396?s=20

Once I collect enough data I will do comparisons.
I think based on curves lso i can identif

Also attached is one minute of averages that can be used to play with calculations and assumptions as they are at this moment in time. Following the spririt of "real" programmers, not much commenting of the code file. Will improve... perhaps...

The time is in UTC and can be corroborated with Stellarium or similar for 180 azimuth, 90 elevation, at:
N 46*23'34.08"
W 63*16'12.36"

Cheers,
Paul

2023-12-14_04.17.52.7_h1p_180-90_spectrum.csv
processor.ipynb

Paul Maxan (microp11)

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Dec 23, 2023, 12:45:14 PM12/23/23
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... I think based on curves l can also identify a patch of cold sky to have a power reading in K at that point.

b alex pettit jr

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Dec 23, 2023, 12:56:45 PM12/23/23
to 'Paul Maxan (microp11)' via Society of Amateur Radio Astronomers
Hello Paul,

You need to Verify is amplitude Units.. are they Power or Linear ?
The way I tested the IF_Ave *.txt saved files  was to insert a calibration attenuator in the RF path 
and verify the change represented the atten as marked on the unit...

Example : an Atten marked  " 6 dB
will  Halve the value of Linear amplitude data
and Quarter the value for Power scaled data


Alex

Paul Maxan (microp11)

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Dec 24, 2023, 8:49:07 AM12/24/23
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Added the 1.4-1.7G Nooelec boom dimensions as well. This is the one that comes with the Inmarsat package from Nooelec.

all-nooelec-booms.png

Andrew Thornett

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Dec 24, 2023, 9:26:48 AM12/24/23
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How much did it cost to buy the 1.4GHz boom from Nooelec alone to upgrade the 1.7GHz mesh to 1.4GHz?
From: 'Paul Maxan (microp11)' via Society of Amateur Radio Astronomers <sara...@googlegroups.com>
Sent: Sunday, December 24, 2023 1:49:06 PM
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Subject: Re: [SARA] Re: Happy
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