Exploring Freq > 500MHz (RSP1A + Nooelec + Sirio Discone)

[Macavity]

After the recent interruption to my progress towards (potential?!) Radio Astronomy... 😛
I resumed exploration of Freq > 500MHz... with RSP1A + Nooelec LNA + Sirio Discone!



With no "Ladder Guy", I poked my new Sirio SD3000N out of the landing window... 🥳
(Also it's a fair bit easier to try out a *general* purpose tests with NooElec LNA etc!)
But ultimately destined to join X30N (upper right) which I use for 2m/70cm SWLing.

Here's the expected SWR for the Sirio Discone (>300 MHz):



First thing I did was REMOVE the loaded whip -- Which gave the following measured SWRs! 😎
(Left with whip / right with whip removed!) Whatever I prefer the thing as a PURE Discone...



A first puchase of "Noname" LNA didn't work at all, so I went for the Noelec *general*
purpose 20dB one... Just to see what would happen when I tried it out with the RSP1A!

CLEARLY 20dB extra gain is not needed for Aircraft... 2m / 70cm etc. but I tried anyway!
With judicious reduction of RF gain it proved workable on e.g. 70cm... But the Discone
SNR was no better than the X30N" (thankfully? lol). Anyway I intend it for higher freq...
So I enlisted the help of the RSP Spectrum Analyser Software:

https://www.sdrplay.com/updated-spectrum-analyser-software-for-sdrplay-rsp-family/

This shows the RF spectrum from 600 to 1600MHz with Bias-T *on* (20dB extra gain):



And, just for fun... Upto 2GHz! (If anyone can ID the major bands in plots... for interest?) 🥳



I IMAGINE the next stage (for attempting any Hydrogen Line 1420Mz) might be some
kind of directional antenna (Satellite Dish came with the house - I've never used it!?!)
Clearly I need a filtered LNA to do anything *really* useful... A Nooelec "Sawbird"?!? 🤔

Hope this is of interest! An ever comments are welcome... 😃

P.S. Some inspiration was drawn from this... "Spectral Occupancy Measurements etc."
https://www.researchgate.net/publication/275649440_Spectral_Occupancy_Measurements_in_Rural_and_Urban_Environments_Analysis_and_Comparison

Edited June 25, 2020 by Macavity

[robin_astro]

I was surprised to find that given a decent receiver lineup the  Milky Way Hydrogen line is detectable with some remarkably simple antennae (eg even a dipole plus a CD as a reflector !) 

https://astropeiler.de/sites/default/files/Hydrogen_4.pdf

From this website

https://astropeiler.de/

[robin_astro]

You could build a "Micro Arecibo" using your satellite dish (fig 14 of the pdf)  🙂

Edited June 25, 2020 by robin_astro
spelling

[robin_astro]

The direct link to the series of articles (in English) is here

https://astropeiler.de/beobachtungen-der-21-cm-linie-mit-einfachen-mitteln

Robin

[Macavity]

Thank you Robin! Great to see the possibilities... and interest!
I'd be fairly happy to hear the "Cosmic Hiss" to be honest... 🥳

A slight pathos that "RF" seems generally quieter there days. 
I could do with a nice strong/steady signal on (say) 23cm? 😸

A few more Hams -  Not everyone is [DIY] angle grinding! 😛
 

Edited June 26, 2020 by Macavity

[wxsatuser]

1700 to 1900MHz is mobile phones up and downlinks.
800 to 900MHz is mobile as well.

https://www.ofcom.org.uk/__data/assets/pdf_file/0020/114266/Frequency-Allocations-Mobile-and-Broadband-below-5-GHz.pdf