Yesterday I tried a complete other #hydrogenline setup, different antenna, the Nooelec Sawhird H1 LNA and the #hackrfone SDR instead of my spectrum analyzer.

Result was good 😃 A clear peak at 1420.544MHz, about 40kHz Doppler shift, with a decent SNR.

I used ‘GQRX’ but found it a bit annoying to tune, it took quite a while before I got the picture you can see. I wanted to zoom much more, but couldn’t make it work.

So what SW do you use for radio astronomy?

Anyway, the signal passed the ‘double sanity check: 1) Disconnect power to the LNA: it goes away. 2) Rotate the antenna away from the Milkyway: it goes away - rotate back: it returns 😃

#hamradio #hamr #astronomy #stem #rfengineering #rfengineer #electronics

Came across this beautiful microwave link station in #norway, a site which operates in a very special way: the signal is aimed towards a reflector in the mountains and from there it is bounced towards its destination 📡👌🏻

It’s not uncommon to do this, but it’s the first time I’ve ever seen one, real life 😃

While visiting sites like this, it’s always a good idea to look at the installation - in this case the waveguide feeds, the dimensions of which reveal the operating frequency area, likely between 8-12GHz.

#rfengineering #microwaves #microwavelink #antennas #hamr #hamradio #radio #radiolinks #keepyoureyesopen #observe #electronicsengineering #engineer #onsite #antennaspotting

Came across this stash the other day, nicely piled up to be scrapped, unfortunately. Was told: grab what you want before it goes .. 😳🤷🏼‍♂️🤯

RF absorber pyramidal panels like these are expensive and really hard to get at as a private person, so it felt like I struck gold 😃

I filled my little car and tomorrow I’ll be back for more: hear-say travels fast in the RF engineering community and as these are located within a secured area with strict access control, I was asked to bring some of it outside the fence 😂

#rfengineering #antennaengineer #antennadesign #hamradio #hamr #antennameasurement

The LNA I mentioned in my previous post, well it’s a #Nooelec sawbird H-Line amplifier. About 41dB gain, centered around 1420MHz.

Look promising indeed 🙂

#radio #radioastronomy #RadioTelescope #rfengineering #rfengineer #hamr #hamradio

My living room as an antenna test chamber 😂 Well, it was a rainy day, couldn’t set it up outside.

I’m testing a 2.4GHz dish, meant for WiFi links, but as it turns out, it has a decent match at 1420MHz so it’s actually usable as a Hydrogen Line radio telescope antenna.

Traversing in front of it, you can see its impedance (S11 for the experts) change. This happens because I’m affecting its near field. In human understandable terms: being sufficiently close to the antenna affects how it performs.

With my newly acquired LNA, this will likely end up being a much more portable Hydrogen Line radio telescope, I have high expectations 😃

#hamr #hamradio #radio #radioastronomy #rfengineering #rfengineer #electronics #nanoVNA

A small walkthrough of my hydrogen line radio telescope, seen through an app which does a really cool AR overlay of the Milkyway.

What happens when I point the antenna to a vertical position, far away from the galaxy?
To things: 1) the 1420MHz signal disappears and 2) The noise floor drops several dB. Effectively this means at I’m picking up ground noise at this low view angle 👌🏻

#radiotelescope #astronomy #radioastronomy #rfengineer #rfengineering #hamradio #hamr #siglent #frequencyfriday

10 years back, I started experimenting, building my own radio telescope. My results, trying to observe the Galaxy hydrogen line at 1420MHz, were positive but in no way impressive.

Years have passed, I have better test equipment today, I have my own lab and I have a better antenna 🤓 📡

So I decided to give it a go last night - and it worked!

Not ideal a summer evening like this, the sky temperature is too high, and my observing angle too low, but at least I proved it possible, it’s a nice starting point 🙂🙂

My setup is a vintage 17dBi standard gain horn and a 38dB LNA, cooled about 20degrees below ambient. I feed this to my spectrum analyzer.

Next step will be to build a larger antenna and try again with when everything cools down in the fall 🙂

I really looked forward to share this - I hope you appreciate it 👌🏻☺️

#radiotelescope #astronomy #radioastronomy #rfengineer #rfengineering #hamradio #hamr #siglent #frequencyfriday

It’s #signalsaturday and here’s a mystery SW signal I picked up at my friends place 😃

5-15s bursts, centered at about 1.5MHz, total bandwidth 2MHz. Starts with carriers 4kHz apart, then spreads out to a noise field, which then goes back to single carriers.

Mostly present weekdays, signal is ‘local’ ie not observed on SDRs further away. No apparent timing of the bursts, occurrence seems ‘random’.

Either it’s 1) alien 👽 (joke) or 2) Some communications channel or 3) some kind of VFD 🤷🏼‍♂️
#hamradio #rfengineering #rfengineer #thetruthisoutthere

Follow-up, I found a beautiful WR-137 flange, tell me, why the hell are waveguide components always either overpriced, beat to sh.t or a combo of the two?!? 🤷🏼‍♂️🤷🏼‍♂️🙂

Well I got lucky (at a cost) and now I have an operational horn with a decent passband between 5.25-8.1GHz 😃👌🏻

I was a bit surprised to find I needed the absorbers but a quick calculation confirmed that anything non-absorbent the first couple of meters will affect S11.

I included a SWR plot as well: it’s always amuses me to see how violent everything collapses once the (half)wavelength exceeds the physical dimensions of the waveguide, approaching the cut-off frequency. Suddenly, all you have is a useless piece of metal 🤷🏼‍♂️😂

I plan to do some free range (outdoor) measurements once this winter clears, stay tuned 🙂

#hamradio #hamr #rfengineering #antennas #electronics #antennaengineer

Cool video I found on abusing a NAND gate into being an RF mixer

https://www.youtube.com/watch?v=3-rqw8MNQsI

#electronics #rf #rfEngineering

This very DIY 10GHz RF source is such a joy to look at, it definitely deserves far more views.
Take a look!

https://www.youtube.com/watch?v=zdfcw-hBPPo

#electronics #rf #rfengineering

Finally, after almost a year wondering how to do it the best way, my Rubidium Standard found a decent enclosure 👍🏼
A massive heat sink at the bottom provides the needed base cooling of the module, the LEDs and the small panel voltmeter monitors lock state, power supply and other BITE outputs 🙂
#hamradio #hamr #testandmeasurement #electronics #electronicsengineering #rfengineering

Detection of very high frequency magnetic resonance could revolutionize #electronics.

https://phys.org/news/2020-01-high-frequency-magnetic-resonance-revolutionize.html

#physics #telecommunications #rfengineering

So, I just discovered this website on #antennas: http://www.antenna-theory.com/

It not only has sections on different types of antennas but also introduces one to the preliminaries required to understand the subject (such as impedance matching on transmission lines with the help of Smith chart).

#electromagnetism #RFengineering #MicrowaveEngineering #TransmissionLines #SmithChart