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My other Aviation hobbys

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Hi all,Thought I would post on my other aviation hobby:Very High Frequency/High Frequency Radio aircraft datalink/voice, beendoing this hobby for more years that I care to mention! I use a HF ICOM RC-75 base station rx along with a Yupiteru MVT 7100 for VHF/UHF.Sortware: PCHFDL HF ACARS decode, Airnav Suite4 for VHF ACARS/SELCALdecode and of course 'normal' voice comms, antenna's are Datong HF Dipole and Wellbrook HF magnetic loop both have rotators also SkyKing VHF/UHF.The amount of traffic to listern to is enormous even with the goodold HF and infact new HF a/c datalink stations are coming on-lineit appears that only a few airlines use it at this time but I believe more are looking into it.a few screens:you can see where my 'handle' comes from now :-) soory about the quality of some of the pics :-(1/ PCHFDL ( HF datalink main screen ) showing info, position reports tx stations, on occasion aircrew send info to ground, arr times wxrequests etc which are sent back and come up on my screen.2/ The Squitters, now you can see where my handle came from :-) but first some info about the HF/Datalink/Squitters:-How does HFDL Work ?ARINC 635-3 aka HFDL aka GlobeLink/HF is based on a number of interconnected ground stations. Each ground station transmits a frame called a Squitter every 32 seconds. The Squitter frame informs aircraft of the system status, provides a timing reference and provides protocol control. Each ground station has a time offset for its Squitters this allows planes to jump between ground stations when trying to log on to the best one. When passing traffic Time division Multiplexing is used (TDMA) this prevents two aircraft transmitting at the same time causing collisions.Let us pretend we are an aircraft. We have taken off and want to logon to the system.Firstly we look at all the ground stations local to us, i.e within 3000 miles, we compare signal strengths look at multi-path and see how busy each one is. Once we have decided which ground station we want to use, we listen to that ground station to see what slots are to be used for random access. We decide on a slot and then send a log-on message including our ICAO 24 bit aircraft address using the log-on air address of 0xFF, we have to use this as we don

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:-eek :-eek :-eek ! Interesting Hobbies, more than I have ever done in aviation. Im mostly plane spotting, flying, Tail number collector,going to the local field and recording some takeoff and landings :) all the basics :-lol !

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Hey Jason :-waveThank you! I have to you send a ' I suffered this post ' certificate :-lol :-lolcheers,Steve

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Hi Greg,On the data link its more or less standard format messages, on voicehowever there has been plenty over the years, a recent one was aa flight travelling up the Carribean routes toward NewYork,he had a total transponder failure and request the NewYork OCA control ( these are only radio operaters and relay a/c info to a relevent atc center) center contact the NewYork Air Defence command about it, a sad sign of the times we live in :-(. Another good setof stations to listern to are the flight service stations ie StockholmRadio etc even with ACARS many companys are still using phone patches on HF ie maintinence problems, wx diversion, arkward and sometimes drunk pax! had one alittle while back (I wont put a name to the company ) had some kind of drastic hydraulic prob, although I didn't hear it from the start, they were talking about an emergency diversion and ' can they make sure the arrester nets are kept down ' no idea which uk airfield that was! I've been listerning to voice comms for 25 years and have only every heard one MAYDAY call, so I guess it is really the safest way to travel, although their have been 3 tragic accidents this last week, maybe you have to look at the wider picture.Concorde is one that people always ask about, heard her many timeson the SM fixed tracks, highest was 58,000ft, I did notice that if thetemp was lower the a/c would not reach a high alt in the gruise, guessthis has a big effect on Mach 2 cruising/height.9/11 and listerning to the NAT OCA Shanwick/Gander etc was very alarming, wont say what I think about the people responsible for that days events ( its unprintable ).Radio was the only reason I got a home pc, then someone showed me FS98, the rest is history and it would appear now that simming is beginning to overtake the datalink radio aspect, can't run both at once, although its cool to have say Cander radio in your headphones when doing an atlantic crossing.Thanks for the interest ;-) cheers,Steve

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Steve,Thanks for the original post which I read with interest.As it is Sunday and we have about 3ft of snow on the ground, I figured ACARS could be an interesting project for the afternoon....It turmed out to be easier than I thought. I already had the scanner and a sound-card, so all I needed was the ACARS software...I checked out your v(PC-HFDL) version but it was payware - however a google a search revealed this link: http://www.geocities.com/CapeCanaveral/Coc...9870/acars.htmlThe author Mike Roberts software (WACARC-07) incudes installation and getting started - but as soon as the software was running and a scanning receiver hooked up to the mic-input I was seeing aircraft (ACARS) messages even before final tweaking!You will need to know your ACARS frequencies for the part of the World that you are in but these are available HF and VHF on Mike's site and the other site below!Mike also includes a section on creating your own position-map display, so before long you too can see little airplanes all over the map :)Also please check out this site: http://home.kabelfoon.nl/~pdw/alp/It contains some additional ACARS information and other neat downloadsThanks again Steve (original poster - I got a new hobby now!)Terry

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Hi ya Terry,Excellent! really glad my post has brought you a new pastime :-coolI too run Wacars which is used to link with this software, which I canwarmly recommend:http://www.airnavsystems.com/ANST/index.htm the chap who programmed the PCHFDL is working toward linking hissoftware with the AirNav Suite4, you will need a 2 channel soundcard,one like SBLive I guess? A typical ACARS message: Flight Summary for KL0753 (PH-KCF) MD11[20021001 2330]/PIKCLXS.OC1/RCL 064KLM0753-DINIM/2355 M084F320-RMK/MAX FL 33082D6[20021001 2334]/PIKCLYA.OC1/CLA 2232 021001 EGGX CLRNCE 509KLM753 CLRD TO TNCB VIA DINIMRANDOM ROUTE51N020W 48N030W44N040W 40N045WFM DINIM/2355 MNTN F310 M084ATC/LEVEL CHANGE END OF MESSAGE527F----------------------------------------------------------------------One of the major snags with HF radio is using 'of all things' a pc near to the antenna's, my old 17in monitor used to send out the most dreadful racket, have now switched to a Dell and things are much better, but my radio gear is still in one room and pc in another,it helps being able to rotate the antenna's to help null localinterference, doesn't always work tho, another prime source is ourown tv, brand new wide screen job and the racket that kicks out! so much for IF testing!, A great deal of my HF voice time is listerning at night, 23:00z onwards, this is a great time with all the Eastboundtraffic, NewYork OCA is my fav at this time, also, so far ADS (vhf datalink posn reports via Satcomm ) is not used in their OCA although it is bound to come, much better for aircrews.--------------------------------------------------------------------- enjoy your new hobby bro,,,,, 3 feet of snow! :-eek and we Britsgrind to a halt with 5cm worth!cheers,Steve

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Steve,I have also d/l "PDW" (version 1.10) which again is FREEWARE and includes decode capability for POCSAG. FLEX, MOBITEX as well as ACARS.It seems to decode ACARS DATA pretty well, and again uses the PC's Sound Card - although there are selectable external FSK4 decoder interfaces built-in (schematic supplied).I live about 40mi East of Pearson (Toronto), and the scanner's rubber-duck antenna is ok for now, I may hook it up to the 2M beam and point it across the pond - see what happen :-lolI hope others, get to try this easy data-mode!TerryPS The snow hasnt deterred outdoor activities.. I live by a lake and there are dozens of ice-fishermen out there right now plus snow-mobiles! (BTW I am originally from Manchester)

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