Got my antenna working for JAERO

[MrBungle]

I found this design for a RHCP antenna online, so I printed it out. I'm using it with a no-name bare LNA I'm powering via USB. I'm using AIRSPY and JAERO v1.0.4.14 and RTL-SDR V4. I'm getting good signals on 1.545.075 currently on 98W. I've never decoded satellite before.

Next up I'll get a Sawbird and spend for some good quality coax and see what I can pull in. I dig this antanna design though.

 

[thebaldgeek]

Congrats! L-Band is a lot of fun and easy to get going with the 'new' 3D printed helix antenna forms.
Sure takes a lot of the guess work out and lowers the bar for entry into satcom ACARS.
Also nice work on using an AR app to find the satellite and thus making sure you can see it from your location.
You can bump the number of VFOs and VACs to get more channels as a next step if you like. I recommend using SDRReceiver vs more virtual audio cables if you do want to get more channels.
Of course, with more channels comes the challenge of reading the data and finding the fun ones. (Do NOT use logging on Jaero to do this).
Not sure if you know about my site, but you might like to poke around and read some more about satcom ACARS on there: Decoding ADSC, ADSB, ACARS, VDL2, Iridium, HF-DL and other aircraft type messages.

 

[srletend]

Looks good. What app did you use for the satellite location?

 

[thebaldgeek]

The app is pointed out on the first page "Inmarsat".

I used an Android app to show a virtual reality view of where the satellite is located in the sky. I HIGHLY recommend you download the app and see what your options are. Do NOT pay for an app to do this, the free versions are fine. Note that not all apps have the Inmarsats in them, does not matter, just pick a sat from the list that is around 5 degrees from the Inmarsat one in your area. This is not rocket science, close enough is all you need at this point.
There are many such apps and I would think that there would be some options in the Apple store, but don’t have an Apple device so cant call any out. (Not sorry).
Here is the Android one I used: https://play.google.com/store/apps/details?id=ftl.satellitedishpointer.sdp

 

[MrBungle]

Congrats! L-Band is a lot of fun and easy to get going with the 'new' 3D printed helix antenna forms.
Sure takes a lot of the guess work out and lowers the bar for entry into satcom ACARS.
Also nice work on using an AR app to find the satellite and thus making sure you can see it from your location.
You can bump the number of VFOs and VACs to get more channels as a next step if you like. I recommend using SDRReceiver vs more virtual audio cables if you do want to get more channels.
Of course, with more channels comes the challenge of reading the data and finding the fun ones. (Do NOT use logging on Jaero to do this).
Not sure if you know about my site, but you might like to poke around and read some more about satcom ACARS on there: Decoding ADSC, ADSB, ACARS, VDL2, Iridium, HF-DL and other aircraft type messages.

It was your site that gave me a ton of data I needed. For example, all my frequency tags are copied from your site! So thanks a ton for everything you posted, it helped me get setup!

Looks good. What app did you use for the satellite location?

It's called Satellite Finder on iOS. I bought it for 2.95 or something for life.

 

[TAC4]

That is pretty dam cool 👍Now go and charge your phone
battery.

 

[737mech]

Do you have the link to the 3D print? Have you tried 600bps as a speed in JAERO?

 

[N1XDS]

I found this design for a RHCP antenna online, so I printed it out. I'm using it with a no-name bare LNA I'm powering via USB. I'm using AIRSPY and JAERO v1.0.4.14 and RTL-SDR V4. I'm getting good signals on 1.545.075 currently on 98W. I've never decoded satellite before.

Next up I'll get a Sawbird and spend for some good quality coax and see what I can pull in. I dig this antanna design though.

View attachment 167585

View attachment 167586

View attachment 167587

View attachment 167588

I like the antenna design its amazing.

 

[MrBungle]

Do you have the link to the 3D print? Have you tried 600bps as a speed in JAERO?

Here's a link to the print. Also, I've been able to decode 600 and 1200 so far. I don't have a Sawbird, I'm using a regular LNA powered by USB. I'm going to pick up a Sawbird soon, and also build a good tripod setup to mount it better. As I type this, I'm pointed to 54W and I'm not getting anything off that.

 

[MrBungle]

Also, I cannot get Scytale-C to work at all. I have the SDR# plugin, but not once have I ever received data. My waterfall is active, just zero data.

 

[737mech]

printing mine now.

 

[MrBungle]

printing mine now.

Please post pics when you are done, I'd love to see. I need to get a good tripod and mount mine better. I'd also like to put it inside something to protect it and get a Sawbird.

In the mean time, I'm pleased to announce I finally got Scytale-C to decode on AOR-W. I'm currently decoding this from Utah.

The only problem I'm having though is I can't keep a lock on the signal even with auto-track enabled.

 

[K5MPH]

Good for you this radio band is a lot of fun.......

 

[TAC4]

That is fascinating AF.

 

[ArloG]

Looks good. I made a RHCP patch antenna. Added a place to switch to LHCP. With a LANA some signals scream in.

I'm interested since your have basically a LANA how the Sawbird compares. Wondering. Could you show a closeup of your impeance match? And did you do any tuning of the helical? What gauge did you use for the helix?

My plan is to use two fiberglass driveway markers for supports with stagger drilled holes for the helix and drilled and tapped on the ends for nylon hardware to mount to the reflector.
Good Job!

 

[Tonypaulino]

hi every one here is this antenna i use for noaa 1.7GHz but doing good job on jaero to.

1.7 Ghz HRPT Helicone Antenna by t0nito

This is a portable light weight handheld HRPT receiving antenna of weather satellite imagery. It can also be used on a motorized satellite tracker.Materials needed:-A metallic conductive mesh, I used aluminum mosquito net.-About 1.5m of 6mm² copper wire-Sheet metal to cut a 133mm circular ground...

www.thingiverse.com

 

[MrBungle]

Looks good. I made a RHCP patch antenna. Added a place to switch to LHCP. With a LANA some signals scream in.

I'm interested since your have basically a LANA how the Sawbird compares. Wondering. Could you show a closeup of your impeance match? And did you do any tuning of the helical? What gauge did you use for the helix?

My plan is to use two fiberglass driveway markers for supports with stagger drilled holes for the helix and drilled and tapped on the ends for nylon hardware to mount to the reflector.
Good Job!

No tuning, I'm not smart enough for that- ditto for impeance. I used I think 10 gauge copper strand wire, nothing fancy. Thanks- I've been decoding super solid after I manually lock onto a frequency. I can't auto-track it, I lose signal. It drifts a bit- but after like 45 minutes or so.

 

[ArloG]

When you start 'getting up there' in frequencies, little changes can make a big difference.
I didn't look close enough to see if you use a single or double helix design.
Usually a small wedge shaped metal strip is soldered to the first 1/4 wave of the helix to match impedance.
A VNA then could be used to match the antenna impedance to the coax.
Or simply making small adjustments by bending the clearance and watching for highest signal.
You would be surprised how tiny adjustments make a big difference in performance.
Not harping on you. But since you have the 'spark' and interest. Check the link out and head to the bottom of the page.

Helical antenna calculator

 

[thebaldgeek]

RX only is a lot more forgiving than Tx, so the little strip is not required.
All the 3D antennas I sold were run over a VNA and a 'worse case' setup (indoors with thin coax) to make sure they were peaked up for L-Band before I shipped them.
The key is the run the first 1/4 or so turn parallel to the reflector., and ensure the length as close as possible to 7 turns.

I've moved on from Scytale-C to satdump. Its vastly better and will stream decoded messages via UDP JSON and so can be filtered and alerts generated for keywords etc.
You can find the L-Band helix tuning tips and STDC decoder information on this website: Decoding ADSC, ADSB, ACARS, VDL2, Iridium, HF-DL and other aircraft type messages.

 

[ArloG]

I rely on hands on experience and the website is very nice. Although I do disagree. And have found that the 'little strip' allows for controllable impedance tweaking. Sure. Just the first quarter turn being parallel to the refector element works. Tiny spacing variations add up to large impedance changes. And a copper wedge gives a finite endpoint to adjust.
Helicals are more forgiving and have better bandwidth than a patch antenna. People often don't realize that the polarization must be reversed if the antenna is faced at a satellite reflector. A short jumper from the LNA may actually work better than a direct connection because you can make an ugly balun with the pigtail to isolate the antenna from it a bit bettter. What I've found. I also have a nanovna. But the trusty HP network analyzer is still tops. Good to 6 GHz.
I never dislike hands-on experience. Always respected. It's just that when you get "up there" in frequencies. The ittle things make a huge difference. My choice would be to fashion a nylon adjustment screw through the reflector to allow finite first 1/4 wind adjustment and limit body effect. But that's me. I've see a lot of sloppy built quadrifiler helix 137 MHz examples proudly displayed by folks. Shame because building one to exacting design specs simply makes for a better performing antenna. Hands down.
Haha. Just one thing from the page link. I read a lot of it. Remember. Silicon is ON the beach. Silicone is why you wear dark sunglasses when you go to it! Silicon makes for a good mortar mix. I wouldn't want to seal the tub up with it though. Gotta' love Dow Corning.