Portable Mini Umbrella Hat Radio Telescope

[Asayama Shin'ichiro]

Hello, 

I was encouraged to post my Portable Mini Umbrella Hat Radio Telescope on this forum.

I was inspired by the work of Alex Pettit - Umbrella Antennas: 

https://www.youtube.com/watch?v=ymclkNnCeCc

It succeeded in detecting 21cm signals from our Milky Way!

I hope you will find it interesting!

S. Asayama

[Alex P]

Hi Asayama,

You should install the LNA at the Feed. The coax will greatly degrade the performance. Your signal level may double or triple .

And the antenna will perform  better with a deeper cake pan than the lid as it acts as a shield  to 290K ground noise RF

Alex

[Asayama Shin'ichiro]

Dear Alex,

Thank you for getting in touch with me!
Yes, indeed, my telescope performance is not optimised.
This demonstration intends to show how easily carry out radio observations with the items at hand.
Such simple home-built radio telescopes would be useful for outreach and education for kids.

S. Asayama

2024年4月22日月曜日 17:51:29 UTC+1 Alex P:

[b alex pettit jr]

Move the LNA to the feed and re-test.

[b alex pettit jr]

Those noise spikes are from your PC .. move it Away from the antenna

[Steve Olney]

Hi Shin'ichiro,

That's a clever idea to use the headband !!!

Cheers

Steve Olney

[shinichir...@gmail.com]

Thank you for your interest.
I was looking for a way for children to enjoy handmade radio telescope exercises without special skills and tools.
I hope that school teachers will find it useful for outreach and education.

[b alex pettit jr]

Hello Asayama Shin'ichiro,

Yes it is a very simple implementation of the umbrella antenna, and seems to work fine.

As previously suggested,

1) try moving the LNA to the loop feed connector to increase efficiency

2) and moving the PC further away to reduce RFI

Please post another plot of the results ..

Best Regards,

Alex P

[shinichir...@gmail.com]

Dear Alex P,

I had time after work today to make your suggestion.
Here attached is a photo of the new observation setup and HI spectrum.

The signal level increased as you mentioned, as well as less RFI.
Thank you again for your valuable suggestions. 

S. Asayama

[b alex pettit jr]

Hello Asayama Shin'ichiro,

At microwave frequencies, seemingly insignificant changes can have a Huge Effect !

Please post a large photo of the spectral plot.

You will also obtain improved performance if you point the antenna more overhead .

>>>  Very Well Done .

Best Regards,

Alex

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

On Thursday, April 25, 2024 at 05:31:32 PM EDT, shinichir...@gmail.com <shinichir...@gmail.com> wrote:

Dear Alex P,

I had time after work today to make your suggestion.
Here attached is a photo of the new observation setup and HI spectrum.

The signal level increased as you mentioned, as well as less RFI.
Thank you again for your valuable suggestions. 

S. Asayama

.

[b alex pettit jr]

Hello Asayama Shin'ichiro,

Try taking data from these bright areas of the Milky Way   

Declination + 20 degrees and Declination + 40 degrees

Chart from CCERA

Regards,

Alex

[shinichir...@gmail.com]

Dear Alex,

Thank you for your suggestion.

I've made a series of observations on the Galactic plane.

I will post the result on another thread.

S. Asayama