How to decode HF ACARS (HFDL) free with your SDR - Monitoring Aviation Communications Episode 8

[@rider275]

I finished this series and the series for the 2020 SDR series. I picked up quite a bit of information. Thank you for your efforts!

[@FrugalRadio]

Glad it was helpful!

[@jackofalltrades28]

Awesome 8 ep guide, I’ll be using these vids for a very long time as references!

[@FrugalRadio]

Great to hear, thanks for your comment!

[@chrispowell3664]

Thanks for another informative video. I just set my monitoring station up in Minneapolis MN this last weekend with my SDRPlay RSP1A and SDRUno. PC-HFDL is a awesome program. I just got my licensed version today. Having great fun.

[@FrugalRadio]

Great to hear about your station Chris and thanks for commenting. There's so much to enjoy with an RSP1A. Enjoy the HFDL decoding!

[@Wayne-Pr]

G'day mate wow what an awesome video with incredible results & how timely Thank You so much I haven't yet got around to decoding HF Acars yet but you've inspired me to pull my finger out & get on with it, to many challenges with SDR's. :-) I've just spent the last few weeks playing with just about every known "VHF" Acars program out there ( no doubt you saw my comments on the SDRPlay Facebook Group I saw you were a member ). I have purchased a licence for PC HF DL & find it a great program currently only running it on VHF Acars, after several weeks of trying to get Acarsd working I finally managed to but from what I can see Acarsd is dead program & no longer supports showing aircraft tails, livery's or rego's nor does it seem to interface into any Acars web servers anymore which is a shame it looks like the Author has abandoned it. I'm really surprised just how little Acars programs there are out there these days & from what I have been able to see over the last few weeks it looks like PC HF DL is the only one that might have any upkeep about it all the rest ( not counting Blackcat Systems which is a very generic Acars decoder ) look like they are dead in the water long ago & are no longer supported by their original authors. What a shame there the likes of PC HF DL or any other Acars decoders out there don't or can't interface into the likes of Flightradar24 or planefinder it would make life a lot easier & a lot more exciting. I have found running dual screen a lot easier running say Acars on one screen & Flightradar24 or Planefinder on the other screen saves jumping around to much. Well done & Keep up the great work, as always looking forward to the next video especially on Web SDR's. Rgs Wayne.

[@FrugalRadio]

Thanks Wayne. You might be interested in Planeplotter if you haven't seen it before. It can take data from various ACARS sources and display the positions on screen in addition to the ADS-B data. Also your fellow Countryman Mike Agnes has a program called Display Launcher that might interest you! Rob

[@Wayne-Pr]

Thanks@@FrugalRadio I'll diarise to look him up.😊 I'm sharing all your videos with an comms aviation buff as well who also loves your videos. Rgs Wayne.

[@FrugalRadio]

Appreciate your passing them along to an interested party. Cheers mate.

[@Wayne-Pr]

@@FrugalRadio Pleasure Rob, do you run an Amazon Affiliate I try to buy as much as possible through the links in your videos.

[@mxcollin95]

Awesome video!!! Thanks for posting! 👏 👍

[@jaym1301]

Hi, Rob. I have a question about the HFDL frequencies listed on your HFDL Resources page. What exactly are the "timeslots" and how are they used? Do they represent the UTC time when the frequency starts being monitored by the ground station, and if so do they stop monitoring the other ones at that time? I'm asking because I've noticed that in the Philippines the Guam, Thailand and South Korea ground stations (or at least the aircraft in SE Asia and Oceania sending messages intended for them) remain quite active at 10:00UTC and later. I'm using an SDRPlay RSP1A and an active K-180WLA 55cm loop antenna with 2 or 3 meters of RG58 coax between it an the antenna's power supply. (I use dumphfdl as I have a Debian Linux OS on my computer.)

[@FrugalRadio]

Hi Jay. Thanks for your question. The timeslots related to a portion of a timeframe. Each ground station is assigned a timeslot & frequency for its squitter. That way when an aircraft tunes to a particular frequency it knows exactly when it should receive a signals from the ground station. The frequencies in use are dynamically allocated by a system wide controller that keeps track of propagation. That way, the central computers can reliably stay in touch with an aircraft anywhere across the world. It's just a matter of selecting the correct frequency and ground station for the time of day. Because of propagation, you'll often receive aircraft that are connected to a ground station that is not closest to them. Hope you're enjoying dumphfdl. I've heard good things!

[@ralphthebrick]

Brilliant, you put some work into this. Thanks for a great explanation and sharing your knowledge.

[@FrugalRadio]

You're welcome!

[@jamesdecalais2619]

Interesting video. You can also use Sorcerer to decode HF Acars with no time limit.

[@FrugalRadio]

Great tip! I tried getting Sorcerer running a while ago, but had no success with it. Glad to hear that others managed to get it working!

[@Wayne-Pr]

Hi James. Can you give me a link for this please ?.

[@timvlismas4578]

Thanks for another interesting video. A Google search for 'hfdl system table 51' will give you the current list of ground stations and frequencies. Downloaded, it can then be used in PC-HFDL.

[@FrugalRadio]

That's right. I updated my copy of PC-HFDL with System Table 51 😃

[@Kriden19008]

Many thanks! Great posts, much appreciated..

[@FrugalRadio]

Thanks for the support!

[@thewind-ne8rh]

great video Rob

[@FrugalRadio]

Cheers!

[@radiokingpin]

Thanks for the excellent video!

[@FrugalRadio]

You're welcome. Thanks for watching!

[@speedbird01]

Rob, can you access any historical ACARS data with regard to mh370? Newbie in London really enjoying your channel.

[@FrugalRadio]

Flight Radar 24 had publicly released it at one time. There may still be replays of it available. You could try ADSB Exchange as well, but I'm not sure if they maintain historical data.

[@dkadayinthailand3082]

Hi. Maybe I missed it somewhere. What mode do we use? USB ,LSB ............. Nice video. Thanks. O , is it USB? Looks like it in SDR Sharp

[@FrugalRadio]

Yes, USB is the correct mode for aviation related transmissions, regardless of the HF frequency in use.

[@dkadayinthailand3082]

@@FrugalRadio Thanks

[@drmisfit]

I was wondering if the HF acars messages transmitted be the same in Inmarsat ? Also have you tried receiving LES ship communications ? Thankyou for your video’s kind Regards Peter

[@FrugalRadio]

Haven't tried LES. The HF ACARS messages are a bit simpler, but you do see some of the same traffic as on satellite.

[@drmisfit]

@@FrugalRadio thanks for your reply very much appreciated 😊

[@mariaviklund4546]

Will PC-HFDL automaticly update the System Table if left on for en extended amount of time? I have DB version 51 but i can see that it's DB=52 that is used now. I have my own license.

[@FrugalRadio]

I believe you need to track down the system tables from elsewhere.

[@consciousness1237]

Another question sorry does pc-hfdl automatically switch to the active frequencies when you have downloaded the table of frequencies. And on a sdrplay can you use a scan list of hfdl frequencies to monitor the system ?

[@FrugalRadio]

No, PC-HFDL doesn't manage the radio. You have to manually tune it yourself. The registered copy makes it easier once you update the system table file as it displays the active channels. But when they change, you have to do it manually. Some folk in the community have cleverly written scripts that read the data from PC-HFDL and tune their SDRs. However I am not one of them!

[@consciousness1237]

Great video as usual, one question I will be setting up my aircraft monitoring system and hfdl will be part of it. The question is do all the comms get forwarded to the IMARSAT side including the vhf acars, I thought they were all connected systems. And its so easy to monitor IMARSAT with a patch antenna. Or do I need separate capabilities. AA4CP Chuck Port Salerno FL USA

[@FrugalRadio]

Hi Chuck. Thanks for watching! There are 2 organisations, SITA & ARINC that handle the back end services. All the messages sent and received travel through those providers. When ATC message an aircraft, the signal goes to a central server. The server knows which media the aircraft can be reached on - VHF, SATCOM or HF. The server then chooses one of the active connections and relays the message. The controller sends a CPDLC message. She / he doesn't know if it gets delivered via ACARS, VDL/2, HFDL or SATCOM. The same process happens in reverse. When you decode the various ACARS messages, you can see the aircraft communicating with the ARINC / SITA server advising them when a connection status changes, and what the current default standard is (VHF / SATCOM / HF).

[@alainbroekema5000]

Thank you very much Rob !

[@FrugalRadio]

Glad to be of help!

[@thewind-ne8rh]

hi Rob the link for PC-HFDL is for vista os and is not compatable with windows 10 that i use can you point me to a nother trusted site?. Tim

[@FrugalRadio]

To the best of my knowledge, there has not been an updated version made. It runs fine on Windows 7. Perhaps it would run on Win 10/11 in compatibility mode. However this is not something I've tested.

[@joseneves2822]

Another excellent video 👍

[@FrugalRadio]

Thank you Jose.

[@greywolf3211]

Just found your channel and love it thank you. Can you do a tutorial on the SDRUNO?

[@FrugalRadio]

Welcome to the channel, sir! I haven't spent a lot of time on SDRUno, but perhaps it's time I did 😉

[@stevehageman6785]

Thanks for sharing! :-)

[@FrugalRadio]

You're welcome!

[@MarkPentler]

step 1: get HFDL up and running step 2: get angry at how many planes ping the wrong ICAO hex on HF vs ADS-B step 3: run node-red to find/replace hexes on the way into your map. This was my week last week.

[@FrugalRadio]

Wow, good job! I keep wanting to play with node red, but haven't quite got there yet!

[@Lordabememes]

can i use RTL-SDR V3 ?

[@FrugalRadio]

In Direct Sampling mode, you certainly can. Reception won't be as clean, but if you are not picking up too much noise, then yes!

[@tristanmills4948]

The paid version also only displays numbers, unless you have the latest system table. That might be received off the air, but you can download it - either the HFDL groups.io group, or a bit of googling will lead you to one. The latest seems to be 51 (hex 33) which is from 2019 I believe.

[@FrugalRadio]

Yes, System 51 is current.

[@zazugee]

I found the HF frequency of canaries ground station by chance when i was combing the HF band some couple of days ago, but today i got shocked that i picked the strongest signal from Thailand's ground station, i'm using a 12m wire dipole here in south algeria, i think it's not the ideal length tho (my roof's limit )

[@FrugalRadio]

Longer would be better, yes. See if you can get a wire be 20-30m long (random wire). It's always exciting to catch signals from a long distance away.

[@zazugee]

@@FrugalRadio i made a mistake, bc some GS use same frequencies, i'm positive it's GS 17, so canaries, makes more sense to me. I'm gonna put a long wire on my garden, i can use a 30m dipole there

[@FrugalRadio]

HF doesn't always make sense. Quite often the strongest signals are from greater distances. Got example, after dark, you're likely to hear US Air traffic and Caribbean, and South American voice traffic easily. If you run HFDL audio through the free PC-HFDL decoder for Windows, you'll know exactly which stations you are receiving.

[@zazugee]

@@FrugalRadio you're right, i tried and found i could receive shannon, iceland and even NY on some frequencies, but nothing from ME, Russia, or South Africa i guess ground waves maybe over the ocean and continents are bad or maybe multiple reflections over the ocean

[@MitchLambert]

These videos are utterly pointless for novices. You're basically just saying ‘with my red-hot setup and years of experience I can do this’, but not really explaining how to get around the potholes. I’m constantly pausing the videos to see if your settings match mine to try to troubleshoot (largely unsuccesfully) why I’m not getting the same results. Can you try to put yourself in the boots of a true novice when you’re making these videos please? Thanks, though, they are useful. Just a minor criticism .

[@FrugalRadio]

Thanks for the comment Mitch. I didn't realise people were getting stuck on steps. I know I go through things quickly (trying to keep the time down). I'll try to be more mindful, for sure.