RSGB Tonight @ 8 - Discover more about amateur radio direction finding by Bob Titterington, G3ORY

[Music] so hello and welcome to tonight at 8 from the rsgb there are a few parts of our hobby which are guaranteed to get us out and about in the fresh air but amateur de radio direction finding does just that and as we'll see it also can be a great way to involve family and friends later on we'll be meeting kim and flora who've both been smitten by the direction finding bug but first we find out about the principles involved from the chair of the rsgb ardf committee bob g3ory good evening bob good evening david i'm going to be explaining the basics of the iaru international amateur radio union direction finding rules and then there's a few video clips to show you what it's like to actually take part in a competition and finally i'll be discussing ways in which we can make a rdf activity in more of the rsgb regions well we're looking forward to finding out more bob thank you and before bob's presentation a reminder that if you're watching this on monday the 17th of may then this is live and you can add comments and ask questions on either batc or youtube at any time during the presentation or straight afterwards please include your first name and call sign if you have one within the message also please note that you can make this video stream fill your screen on most devices usually by double clicking on the picture or pressing the full screen button but now it's time to find out more about direction finding and go back to bob hello bob hi there right tonight the three of us aim to to tell you about first of all the um a brief history of direction finding from the end of the second world war onwards and david has particularly asked me to say something about the legal obstacles to direction finding using cars on the public highway the format of direction finding competitions comes next because it's important to understand that and then i'll take you through the kit you need to take part and also very important the things are available on loan you don't have to have all the gear to actually go out and try it i'll give you a summary of the two frequency bands which are used we use 80 meters and 2 meters and and then you get the map five minutes before you start the the competition and in that five minutes there are a lot of things you need to be doing and so i'll give you a briefing about that and then we have a series of video clips to show how a competitor tackle the the problems and challenges of a two meter event there'll be a contribution from kim and he'll tell us how he came to take part with other members of his local radio club and then flora flora jolly will tell us how she came to try df by going out with her dad who just happens to be a licensed amateur would you believe um then i'll be describing the format of the regional 80 meter events which are tailored to cater for newcomers and finally the efforts being made by the board of the rsgb and and the ardf committee to extend um the coverage of ardf across more of the rsgb regions but first a little bit of history after the war finished and we started to get our licenses back ds started up again and in europe it was mostly the scandinavian countries who led the way now you need to understand that back then top band and privileges were only available to us the irish republic gibraltar and czechoslovakia goodness knows why czechoslovakia had it but anyway they did but none of the other european countries could use top band so when they started direction finding again using surface wave that's a lot medium waves where the signals are and propagated in contact with the ground they chose 80 meters being the lowest frequency band that they had available and it's just persisted to this day and it is still used as the surface wave direction finding frequency now the next thing that happened was in the early seventies um the arrival of the handheld radio the handheld two meter radio coupled with the issue of uh license free vhf only licenses this spawned um a bit of a boom in direction finding in radio clubs somebody would go out hide somewhere and back then the rules for rallying on the public highway were pretty much non-existent so you could do exactly what you wanted and we all roared off in our cars and looking for people hiding in pub car parks and we all had a jolly time now the next thing in my brief history may seem a bit odd to you the end of the soviet era in 1989. now the reason why this is significant is that in the um warsaw pact countries they had state-sponsored community clubs and these community clubs would pay you your expenses to go out and do orienteering and as it happens direction finding so all these eastern european countries have got 40 years of building up a chance of people who've done adr ardf are experienced in it are keen to carry on doing it and so there's a lot of activity in eastern europe but it wasn't until 2003 that the rsgb started using the iaru rules which i'll explain be explaining in a moment the classic format which i'll be telling you about was extended in the early naughties to encompass sprint that doesn't mean you have to run faster it means that you only get 10 seconds to take the bearing instead of 60 seconds and fox o which is a combination of direction finding and orienteering you get a map with circles on it you use orienteering to get the vicinity of circle and then direction finding to track down a very low power transmitter which you can then hear in 2010 all the other iaru regions adopted the region 1 rules and so therefore um df is now a world activity right so let me now take you on to the legal obstacles to car based df hunts and there have been some significant changes in the last 10 years i think most people now know that the road traffic act rta and bans racing and trials of speed on the public highway these um the tightening up of rally of car rallying came in 1969 with the motor vehicles competitions and trials regulations and the department of transport have now given the responsibility for operating these to the royal automobile club this is not the the mob who will collect your car from the roadside when you break down but the regulatory body for motorsport now the rac have introduced what they call navigational scatter events now for navigational scatter events you don't have to ask anybody for permission you can drive precisely where you like ideal for direction finding but unfortunately there's two or three snags first of all you can't you have any form of timing for any part of the competition whether it's on the public highway or not you can't use minimum distance as a way of deciding the winner and of your control points no competitor must visit them all so how could you devise a possible format for a legal event well what you could do would be to send somebody out to hide somewhere and then specify say six control points and tell each competitor to go to a designated four of those so you obey that rule and then at the end to give a good reference of where they think the transmitter was located so you're not actually driving to the location but you're using direction finding techniques to find out where it is so it is possible to legally have a car based df hunt perhaps of a different saw than you you first realized but i'm afraid there's another elephant in the room here and that's called third-party motor insurance cover now you only have to turn the tv on at night to be bombarded with ironconfused.com or go compare and some welsh tenor sings at you or direct line whose adverts look as though they borrowed something from the lego box or lv with their green colored cars and they're desperate for your business and they are trying to reduce the cost of your motor insurance and one way they can reduce the cost is by reducing the risk and so here's an extract from my issue policy which reads this policy does not cover use for racing pacemaking speed testing trials or competitions now somebody said to me well i i i take that to mean motorsport competitions so i said to him i'll tell you what his name was i said to him look if they meant motorsport competitions they'd have said motorsport competitions and they don't so it includes direction finding competitions now of course if you want to take part in a navigational scatter event you're going to have to go to these insurance companies and ask them for an additional third-party cover to cover you for taking part in specified types of competitions they will of course charge you more for that but you can get third-party cover but i ask you how many members of the average radio club have the additional third-party motor insurance cover so that they can take to the roads in a navigational scatter competition and without without being devoid of third-party cover okay let's move from that on to looking at the iaru rules and here's a diagram which shows you the race former now if you look down the left hand column here there are five transmitters to be found and they're numbered one to five all these five transmitters are on the same frequency but not all at the same time first of all transmitter one comes on and transmits for one minute shown here by this first red blob then it shuts down number two comes up and transmits for one minute then three then four then five and each transmitter will um send some some something in morse code and let me show you first of all um a transmitter here we are and they're quite small as you can think you can see and inside the box there is a dip switch and a pic processor and you can set the dip switches to give you the identity of the transmitter this one has got the dip switches set for number one so if i turn it on we can hear it [Music] one dot so that shows its transmitter number one let me just change it to something else let's have um let's do uh number four if i can get the dip switches check yeah there we go so now it's i've told it to be number four so four dots tells you it's number four now in addition to knowing which one it is in the in the sequence there's also um a procedure to prevent people from uh cheating well cheating who would she to prevent people on their way to the competition from tuning in to the hidden transmitters and taking a few furtive bearings so they arrive at the start knowing pretty much where everything is then a delay facility exists you can set the dip switch for a certain delay for example if you set the dip switch for three hours delay you then at seven o'clock in the morning get all the transmitters together in one place and there's a phono socket here on the pcb you plug a switch in as common switch to all five transmitters turn the transmitters on and at seven o'clock exactly you open the switch and that tells all the transmitters when time zero is and then transmitter number one is going to start transmitting at three hours exactly later ten o'clock by which time you've got all your competitors to put their track their receivers into a pound where they can't get at them and so therefore um cheating becomes unviable now um let me next tell you about the um the the the comparison between the the two frequency bands that we use 80 meters and two meters 80 meters uses surface wave and it's like using the ferrite rod on on the medium wave radio you've got on the window sill in the kitchen or which granny head on the window is still in the kitchen when you rotate the ferrite rod around there's always a point where if the ferrite rod is pointing directly at the transmitter you get a reduction in the signal strength and this is called a null and those nulls are very sharp and so the bearings you get are pretty accurate as long as you keep away from metal fences and power lines you'll get good results but the sensing of the threat rod is bidirectional and there's a procedure which you'll learn about if you come to an event for resolving that 180 degree ambiguity it's the best band to get started with because surface wave propagation gives such dependable results the other band that's used is two meters and here space wave propagation is involved the signal no longer follows the and certainly the interface between the ground and the air it will go in straight lines and when it gets to the top of a hill there'll be a bit of diffraction to take it down into the valley at much reduced strength the bearings that you get are affected by screening and particularly by reflections particularly in contoured areas where nearby hills can give you a very false idea of the direction of of the transmitter the direction of arrival of the signal in other words is no longer necessarily the direction to the transmitter however the best place to take bearings are the tops of hills as you might expect the sensing of direction is intuitive because as you'll see in the video and the the competitor is waving an aerial around and sensing the best direction so it's a much bigger challenge to assess the um the effects of all these reflections and so perhaps somebody with a bigger brain um has a better chance of winning um let me just now um tell you about what you need in an ardf receiver obviously you need something with tuning range filtering and sensitivity that goes really without saying but for best results what you need is an am receiver with no agc remember you're sensing the direction of the transmitters by observing when they're strongest you're observing the changes in signal strength fm receivers have a limiter to improve the signal-to-noise ratio and these limiters of course and will also have an effect on the strength of the signals and yes fm receivers can you be used successfully to for direction finding but an am receiver with no agc is always better the other thing you need is excellent gain control because you want to be able to sense the variation in signal strength four kilometers away and then when you get 40 meters away from the transmitter and the signal is pounding in because you're so close you don't want the receiver going into not quite meltdown but just becoming completely unusable it just gets load of signal wherever you point it you still want its directivity to be apparent right now the next thing that's necessary is to prove that you've been to the to each of the transmitters and there are three ways in which you can show that you've actually been there now at the transmitter you're going to to come across something like this a bit of a pole a marker of some kind so that you know it's not not not um hump the thimble this if if you get within um visibility of the transmitter you're not expected to pick the transmitter up you pick the marker up and this one's got an electronic timing box on the top by sport ident now the competitor carries a what we call a dipper here's my dibber and i have mine on my index finger and this is the the box for transmitter number three and if i insert my dipper into the box it lights to say yes i registered that and what's happened is that the box has written to the dibber its identity transmitter number three and the time so therefore i'm carrying back to the finish the information about which transmitters i visited and what time i got to them now that's really for the national competitions and international competition it's universally used but for regional competitions it's more usual to come across a different method and that is the use of the needle punch this is a simple punch which is hanging beneath the marker and you'll have been given a control card with boxes for each transmitter on it and you take the needle punch and if it's transmitter among the three you will punch the card in the box for number three and the needle punch might be a square might be a triangle a circle this one's actually the letter f and when you get back to the finish you'll have a certain set of symbols on the control card to prove that you've been there and finally something rather topical in these coved times um we generally have a paper plate on the ground with a letter written on it and you simply have to collect the letters that you observe at each of the transmitters to prove that you've been there and that's completely touchless you haven't had to touch any part of the equipment and deployed and for the event everything that you've used is an individual thing now having proved that you've been there let me um while i'm showing you a few things tell you about the other things you need to take if you're coming along fresh to the the sport you'll be borrowing a receiver and it's normal to ask the organizer beforehand to save one for you there's only about 10 of them available at each event and we don't want to run out and by offering them more receivers to people than we've actually got to lend so just let us know you want one and we won't put one on side on one side for you but bring your own headphones and a because there'll be better anything we can lend you and anyway we gave up let them lending them to people because the mortality rate is too great the next thing you're going to need is a compass and one of those with a rectangular base plate is ideal because it can be used as a protractor as well now there's not time in this presentation to tell you how to take a bearing and plot it onto a map but there are plenty of people who do know who can tell you but many of you will know anyway and you'll see in the second video me doing that at transmitter number two of actually taking the bearing setting the compass and then being able to plot that onto the map now having mentioned the map you're going to need some sort of lightweight board to put the mat top map on and here's a piece of sort of plastic corrugated cardboard it's it's the construction is the same as corrugated cardboard except it's made of plastic um this actually came from a waitress advertising thing on one of the bollards outside the store and i blagged it off them after the offer was was over and it's brilliant just cut it up into a4 slices and you got yourself a lovely and lightweight stiff mat board if it's wet you can bring one of those plastic folder a4 plastic folder things to put over your map when you've paint and stuck it onto the board with the plastic tape which i've stuck on the side there and you'll need a pen in order to write on the plastic so you'll need a spirit based pen a fine tip not super fine fine tip use red because red isn't used in the map printing and so always stands out and i have my pen on a bit of string and a safety pin and i pin it to my clothing it's one less thing to have stuffed into a pocket there's two more things which are useful a whistle in case disaster strikes and you need to you twist an ankle or something and need to call for help and finally for use in the bigger competitions the rules say that there will be no transmitters um within 400 meters of each other in other words at least 400 meters between transmitters and in this country we normally adopt there'll be no transmitters within 400 meters of the start so if you're doing a national competition you'll want to draw this exclusion circle onto your map and therefore this stencil of this type is quite useful this is the center point where you put that over the start and then for a one in ten thousand the distance from the point thing here to the edge of the circle is exactly four centimeters which is 400 meters on a 10 hour map and you'll see that in the video in a moment right so that explains the things you need to take now let's just go back to the slides and i'll just show you the typical sequence which you'll experience at a competition and you you rock up there register and pay if you ask to borrow a loan receiver then you can collect that no cost but if you lose it we expect you to pay for it nobody's lost one yet by the way now if you and you've done it before you you get your name on the start list and you do not get your map at this stage and then at the start minus five minutes you collect your map and you've got a crucial five minutes and the first video will show you something about that and if you're a newcomer you can we let you take bearings on all five transmitters give you the map straight away before you start you can take bearings on all five transmitters and plot them on your map there'll be a mentor there to help you deal with how to sort out the ambiguity of 80 meter receivers and also to look at your plotted bearings and say they look great you're good to go or i think you ought to have another go at number three or whatever the answer is and so by the time you start as a newcomer you will already have plotted five good bearings onto that map and then you get a time on the start time and off you go you all you will get this five minutes um also which this first video is now going to show you right we're now out in the terrain and i've just been given my map so it doesn't blow away i've already attached it to the map board using those bits of grey tape i showed you earlier first of all i need to use the stencil to mark in the region in which no transmitters are located you can see that quite a chunk of the area is taken up now let's just look at the contours which you won't be able to see very clearly on the video but let me tell you that the top of the hill is here and that it the slope goes down quite quite a lot and we have this low-lying area down here this part here isn't being used today now my assessment of this at the start is that anything over here is going to be trapped between the edge of the exclusion circle and the edge of the map it's likely therefore that the planner will want to put a couple of transmitters down in this low part and then this long tongue of land also offers opportunities for him and um so we might find say three transmitters down here two transmitters there and once the i'm allowed to turn on my receiver i can start taking bearings to try and find out and get some idea of where the transmitters are located okay can i just summarize the the things that came out of that um i was effectively doing three things there one was looking for a location to start taking the bearings and with the top of the hill being um pretty much due north from the start that was clearly in my mind as a good place to go for and from that top of the hill site and you look for somewhere you can get to within five minutes don't spend more than five minutes trying to find a good place so i head for the top of the hill secondly and i i worked out the contours and got an eye head around the topography of the land and then finally i was using um the the trying to pretend i was the planner and coming up with the conclusion there were likely to be three transmitters down the slope to the the east and a couple of transmitters in that bit that goes up to the the north west um so having learnt those lessons let's move on now to the second video and the this is quite a few things in in in this one it shows the first two minutes of the competition and you start at the time that transmitter number one starts transmitting the competitors start at five minute intervals you see and everybody starts when and then transmitter one first transmits so the video opens transmitter one has just started i've just started moving and i'll explain in more detail when you've seen the video what was going on so here we go plug in the phones see what we get [Music] swing the aerial round and max signal surprisingly from my left turn the gain down try and get better response yes it peaks up there that must be between the exclusion circle and the edge of the map well i'm not even going to bother to plot that because it's easy to find so that must pin that one down to within the nearest hundred meters so that's a real gift from the planner okay puffing away as i head up towards the summit [Music] okay transmitter one finishing transmitter two now starting up [Music] that's down the hill in fact let's plot that there's the bearing that was the maximum the compass round like that find me pin i guess you're out there so that's number two down there right carry on towards the top of the hill so i got that bearing taken and plotted well within the 60 seconds right on now onto the hill do battle with the highland cat right so i'll go up to the hill and take some more bearing of the other transmitters okay that was quite a confusing video and so let me just explain in a bit more detail what was going on first of all was that manic swinging of the aerial in all directions it looked completely random and uncontrolled but it wasn't now as i left the start here heading up the road in in this direction just draw a little line show up the road there and i i said that i thought there was um a signal coming in from the left now it's one thing to say i think there's a signal strong signal coming into left but what i wasn't wasn't sure about was is that a transmitter to the left or is there a stronger transmitter over here to the right even stronger and what i'm actually listening to when i point the aerial to the left is getting the real transmitter off the back of the beam so i swing the aerial all the way around to make sure that the loudest signal is coming in from the left so let me just plot where that was going to be i got it to the left so therefore the bearing which i didn't bother to plot was going to be like that and let's just call that transmitter number one now my comments about well it's between the exclusion edge of the exclusion circle and the edge of the map that's why it was such a giveaway because it can only be in this tiny area no more than 100 meters by 100 meters down here so what a gift from the planner that was the other thing which you might have noticed at that point was that i turned the gain down and that's crucially important because when the gain was high it's the human ear brain doesn't respond to changes of amplitude very well and on the video you may not have noticed but as when i turned the gain down it became much clearer that there was a peak in the signal whereas prior to that that wasn't quite so obvious anyway having done that i then trundle on up tottered up the road here to um the the top of the path there and i then set to and took another bearing and you might have noticed that as i swang the aerial from side to side um i was i sensed when the signal began to fall off to the right and i sensed when the signal began to fall off by the same amount to the left and then picked the mid point of that as the um that the bearing that i was going to take and it's that checking one side checking the other side choosing the middle which is the key to getting the bearings on two meters and i then can plot that bearing like that and that is going to is my bearing down to transmitter number two and this here is uh an outer bounds area and uh number two will be down there let's see i can draw a little two here i'm hopeless of this right that's supposed to be a two by the way okay i then went on to the top of the hill this wasn't shown on the video and i got to the top of the hill and i then took bearings on three and four and perhaps no surprises really um but the bearings on three and four were pretty much the same like that and i also got a bearing on transmitter number five and that bearing came in pretty much like this over there and so i've now got enough after once this one sequence it might take you two sequences you're lucky if you can do it in one because getting all those bearings plotted in 60 seconds each i don't often manage to be honest with you i usually go into the second cycle to get them all but anyway you end up with that picture and you can now come up with your game plan and my game plan which seeing that the prediction i made whilst waiting for the start that the be three transmitters down here in the lower part was wrong there's only two two and five i've then got two other transmitters over here uh one of them could be in uh the um this forest road comes up here around the edge of the hill so this is much lower than one could be on the hillside here in the bracken the other one is bound to be further down they might both be further down on the scale here you can see that 400 meters from there to there and can judge that and you can see the number of options for putting three and four in there i then come try and cross these fields if i could find gaps in the hedges so to come in back into the wooded area here come up this path get one here and then cut through to the finish that's my game plan that's how i'm going to do it the only other thing i need to sort out is where am i going to go for the second uh transmission i'm going to take i'm going to go for two where am i going to go to try and listen to the next transmission to two the place i've chosen is down here because if i run past it i can run back the outer bounds area is there so it won't be in that if i haven't gone far enough i can carry on down the path or if it's somewhere across in the this lower area i can take this track northwards so the next bit of video is going to start here at um this this track junction here so let's watch the next bit of video and then when we come back i'll explain what was going on there i'm standing here down at the corner of the outer bounds area and that's one just going off the air and there's two which i'm chasing it turn the gain down try and run it down there's signal peaking follow the bearing [Music] somewhere in there [Music] tree in the way [Music] goes off right keep going ah there it is great great not easy to find but just managed to run it down in the time i would have kept going on that last bearing if i hadn't seen it in the hope that i might spot it okay here we are punch that and the way to the next one okay get out of here and i'll just stop for a moment take time out and say explain what i'm doing next so i want to get out of there if i can right here we are right now i'm taking time out so i was standing here at the start the video at that track junction and when number two fired up um i opted to go up this track here northwards and then i became aware that the transmitter was off to my right somewhere and i went in somewhere like that and transmitter number two was about there and i got it as you saw now while i was uh hanging about waiting i got down there in time um to with some time to spare and i heard transmitter number five on the air while i was waiting so whilst waiting i took a bearing on five and got a bearing like that now you remember that i got a bearing on five from the top of the hill and so at this stage having whoops hang on a minute getting this to work it was flora's dad put me on to this way of uh doing things called snip and sketch right so there's the bearing i got from the top of the hill and so i've got two i think five is about here so what i did i came out of of two to this track came up here is the green bit's a bit gross he came up this oh sorry up the path there and then when the the next bit of video starts i'm standing about there that's there expecting number five to come up to my left so let's see the next set of video and see what happened okay since the last transmission i've got myself out of that track had to come down to here come up this track here and i'm now somewhere about here and there's five fired up heat up it's over there see how i move about take the bearing [Music] now the edge of the map's just over there [Music] somewhere by that yew tree yeah see how it peaks up keep swinging the aerial yeah dodge the grass right can't be far the edge of the area is just whether you can see the sky ah there it is straight in front number five brilliant okay a bit of breath and punch okay let's just take stock now right you will have seen there was a bit of confusion in my mind at the beginning of that bit of video because i was expecting it to come up to the left and i moved forwards and it obviously wasn't from the left and got onto this track started running around this track and then sort of curved into it with the edge of the wood which i kept blathering about and being there and that was was coming up and i was waving the aerial from side to side all the time in order to sense the direction of the peak and you can only sense the direction of the peak when you feel the signal dropping away to the left and then dropping away to the right now having shown you how to find the first two transmitters um i'll just summarize the rest of the competition from there i came out onto this forest road followed the forest road up beside the boundary wall skirted the high part of the hill went down got three and four came back crossed the fields into one and into the finish in order to complete the competition now that's the um sharp end if you like of direction finding but it's not all about lycra and running folks you can get a great deal of pleasure in direction finding um by taking um a rather different approach to it all i'd like to introduce kim who'll now tell us about how he got into direction finding and how he enjoys it and what he likes to go out and do kim hello kim taylor n0 knv a mere slip of a lad at 66 years old but only four and a half years in the hobby bob's asked me to say a few words on a rdf from a newbies point of view which i'm delighted to do now i'm interested in all aspects of amateur radio i'm active on lots of bands including contesting as well as being a volunteer at the national radio center at bletchley park i'm a member of our excellent local radio club the rugby amateur transmitting society the rats and one of the members there jeff g3 tqf he who's always trying to nudge us into new activities god bless you jeff um encouraged me to have a go at ardf a couple of years ago i managed to persuade my friend pete 2e0p and zed to come along as well on the first occasion we arrived at the site where we were greeted by bob david and some of the others we were given a full briefing and shown exactly what to do everything was provided apart from a clipboard a compass and a pen and they had everything else the receivers uh the maps everything we were then given extra time to hear the beacons run through their cycle in order to plot the initial bearings the lads were kind enough to check our bearings to make sure we weren't going to head off in the wrong direction initially although that might have been good fun for them we then set off to find our beacons into the woods and clip our record cards to prove we were there now obviously there is there's a target time to do this within we failed to get it done within the time and decided that we just wanted to concentrate on being able to find the hidden transmitters in the woods we walk by the way we don't run we were absolutely hooked after the first go and we've been back a good few times now and finally there's no pressure to wear lycra you'll be pleased to hear i'm in my mid-60s and i'm clearly no racing snake so you don't have to be athletic to do it it's great fun out in the fresh air a bit of exercise but playing radio in a different way there's only four in our club that are particularly interested in the ardf adrian m1aqx having joined us more recently so the regional events that bob runs are absolutely ideal uh our xyles even ended up coming along after we enthused about how much fun it was so so they came along too and they were hooked also so i can just say to you give it a go it's great fun you'll be given all the help and guidance that you need and why not give it a go the only downside is that you can end up getting so hooked you treat yourself to a really expensive posh receiver okay best 73 give it a go kim taylor m0kmv thank you very much kim now the the other person who's with us tonight is is flora jolly and she's going to tell us how she got involved and her reactions and experiences of direction finding flora hi my name is flora i'm 14 and i'm from lincolnshire a couple of years ago i tried ardf for the first time my dad asked me if i wanted to go and he'd done some before in the past and i had done some orienteering so i decided to give it a go at first when it was explained to me it sounded really complicated and i wasn't really sure what i was supposed to do but when i got there and tried it it was actually much easier i thought it would be we were given a headset and a receiver and also a map and we had a compass and we would listen to the beeps from the transmitter and draw a line on our map in the direction that it was coming from and then we'd move to a different place and draw another line and eventually they would all cross and that point that they crossed out was where the transmitter was so we just had to run and find it we're out for about two hours trying to find all of them it seems like a really long time but when you're actually there it doesn't feel like two hours it goes by quite quickly and you don't have to find all of them if you don't want to hopefully i can get better in the future so i can go without my dad and by myself and it's quite fun because it's like a puzzle that you have to try work out when i've done orienteering that's following a set course but in this you make up your own course to try to find them and i would recommend it to other people because you get to spend time running outside but you don't have to run you can just walk it if you don't want to run and often with your ice cream at the end which is nice right thank you very much flora both kim and flora are with us tonight to answer any questions which you have later on but let me move on to talk about the two different types of events which exists regional events and national events the basic fundamental problem is that there are an insufficient number of people interested in direction finding in any one radio club as kim said there's only three people or three or four people in his club who are interested which really best make it a once in a year club activity but the rest of the time um it's it's really a non-starter and direction finding is best operated as a regional activity so that the small number of people in each radio club can come together and have all the fun and enjoyment of doing direction finding within the region let me tell you about the difference between regional competitions and national competitions what would you expect at a regional event well we use 80 meters only at regional events because the bearings are so accurate as as has been said already the receivers are available on loan and there are two classes at a regional event one for people who've done it before and another class for people who are coming along as newcomers and the newcomers as i said earlier take and can take and plot the bearings on all five transmitters before they cross the start line so they can go out with the confidence that they know how to take bearings and plot them there's bet mentors on hand to look at these plots and tell you if they're okay and also to show you how to use the receiver to resolve the ambiguity of 80 meters the time limit which you've heard about proof of finding usually controlled hard and needle punch and there's usually a small fee just to cover the cost of the maps and incidentals now at a national event it is higher up the scale as you'd expect the traveling distances will be much longer um very often by definition both the two meter band and the 80 meter band are used with two competitions on the day to make it worthwhile can borrow receivers again no special arrangements for newcomers and as you saw on the videos you get the map five minutes before your start time there's a time limit of course usually there's a two meter competition with the classic format in the morning and then a smaller 80 meter competition after lunch perhaps a a five transmitter sprint or a full ten transmitter one or a fox oaring proof of finding the transmitter is usually electronic punching sometimes these events are organized alongside an orienteering competition in which case we'll be paying off the order of six or seven pounds to the per competitor to the orienteering club and that this would have to be recovered from you as the fee that you you you pay to us the orienteering club providing the maps getting the commissions paying any land access fees and for the really nice areas generally speaking there's a significant land access fee to pay so that tells you um the uh the the um type of um of competitions now the the the coverage um around the country with the types of event is very uneven um some regions have got regular competitions others do not and the rsdb df committee and the board are trying to extend the coverage of these regional events in more regions of the rsgb here's what we've got at the moment and the map on the right shows you the rsgb regions it's taken off the rsgb website and regional events take place in the west midlands in northern ireland they're starting this year and greater london and the south east and the east midlands and one of the things we're currently doing is is trying to get more people to run events in the regions now the rsgb board has provided us with some um financial support from the legacy fund to build two kits of of ardf equipment that's receivers and transmitters which are intended um to go out on loan to two regions where there is no activity on an extended two to three year loan so that they can kickstart activity in their region and the deal is is a simple one but the offer is that you provide in your region five simple events each year one a month from may to september and you'll loan the kit for two to three years to get you started and one of the purposes of of of tonight is to see if anybody will will step forward and to take up this offer at the stands which we've had at the ham fest and the convention and frequently we've met in england people in regions three and four and from the south west and east anglia and there is interest out there it's just that it's so thin um that it needs some sort of catalyst to bring people together and it only requires two or three people to get together to run such a program i think northern ireland got three people doing it and one's particularly building some transmitters and the other two guys are organizing the event and finding the area and so on right here are some events coming up in the near future for newcomers next sunday at hinckley there's an event in frost meadows on the 6th of june there'll be one in the area of high wickham and beckonsfield on the 13th of june there's an event in the west midlands adjacent to the m5 junction one and finally northern ireland have got their first event on the 19th of june now you can get more information about direction finding from a number of sources first of all the web pages can be found at so it's a bit faint www.rsgb.org that's the rsgb webpages and go to the main site and select on the air and you'll see the ardf tab over on the right hand side of the screen there's a reflector at www.groups.io you can sign up for the rsgb hyphen ardf group and your you'll find information there there's the rsgb book on radio orienteering and then you can see that on the screen the cover of that on the screen and and that is available from www.rsgbshop.org and finally there's of course me and you can contact me ardf dot chairman at rsgb dot org dot u k now to conclude ardf is a great radio based hobby it is huge fun an outdoor activity for for everybody it was once called hide and seek for adults and there's a lot of truth in that but it's great fun so why not come along and try it um thank you everybody and we'll be the three of us will be delighted to uh try and ask any questions that you might have thank you well thank you very much bob a really concise and detailed look at ardf and what it involves and it's really good now to to welcome kim and flora live as well as you bob so let's have a look at everybody tonight hello hi i think you'll need to by the way unmute both kim and flora before you ask some questions in a moment but we'll go back to some questions now and um we'll we'll come to you in a moment so firstly from let me have a look james g1 fqx he asks re the question of third party insurance for car based events has anyone considered buddying up with a local car club to do a joint df stroke navigation event uk car clubs have access to the relevant insurance and event permits he said have you heard of that bob no we haven't explored that i'm not sure that the the intersection of amateur radio and motorsport occurs and that often obviously does happen otherwise james wouldn't have made the suggestion but no that's not something that we have done okay well maybe that's something that we can explore um graeme bohr has said last did a df in the late 70s on top band we had a sense aerial to mute one direction is this used on 80 meters or is it an unfair advantage he says absolutely not it is used on 80 meters i didn't want to go into too much detail tonight but when i was talking about resolving the ambiguity on 80 i was in fact thinking of precisely this technique and it is used in exactly the same way today as it was used on top band in the 1970s so as an accomplished user of um sensing on 80 well you'll be feel at home if you come along to an 80 meter regional event absolutely flora let's let's come to you because um i think if i if i might be so bold it's unusual to see someone both where i say female and young on on a tonight today or indeed many of these sort of things to amateur radio so you really got a sense that you enjoyed this had you been involved with your father's hobby before this event he'd uh got some equipment at home so sometimes i might see him using it or i'll i've been out with him when he's talking on the radio so i've seen him using that so i had a bit of an interest in it and also my grandad uses it as well so do you know i'm going to let you into a secret now as well flora because actually we know your granddad sees it because he sent a little message on youtube he's watching you now and he says well done flora 88 from grandad g4 jco so there we are good to see all right and kim for you i mean this is i guess you you started in the hobby in the fairly or traditional things getting on the air with probably with voice and maybe other modes as well was this something that you knew about when you first got involved with amateur radio no absolutely not my name was jeff g3tqf of our club that cajoled us at first but then there was no holding us back it really it really is just great fun i think the only improvement i'd make is to the uh the hole punch system is to have a bacon butty at each one because you definitely want all five things that that sounds more that sounds like something i'd enjoy as well there and by the way i should remind you at home now by the way that um if you'd like and ask a question about this to bob kim or flora and you haven't already done so please do it now either on youtube chat or on batc messaging we'll be happy to read those to them and don't forget if you do that to include your first name and your call sign as well if you've got one i've got a couple of other questions come up now from phil2e0vz asks what is a typical time allowed to locate the five transmissions for a regional event he says it varies a lot you do get some very experienced people doing it who can get around the five in an hour um you then get people who are um coming for the first time or have only done one or two events previously and the the two-hour limit is is a good um a good objective for them but as you heard um you know guys can get really really into this and absolutely determined that they don't care how dark it's getting they are going to find all the transmitters yeah i mean one of the things i was going to ask you you did very clearly mention of insurance that would be needed if you're going to try and do it by car and clearly quite a few obstacles there but if a club was to arrange something like this on a local level on foot do you think they need to consider insurance for that because clearly there is the possibility of of tripping over falling over anything like that well the the rsgb um provides what's public liability insurance and your affiliated society membership gives you that cover which makes it available to you if it's the members of the rsgb committee or the officers there's a separate insurance policy for them which gives the same sort of cover of public liability and it's standard procedure that when you're going to a landowner say you want to use a country park and you go along to the local council then you can go along and i'll provide you with a copy of the rsgb insurance if you're not doing it as a local club but just as an rsgb group then i i'll send you a letter from the broker a copy of the letter from the brokers certifying that the the cover is in place and that seems to deal with the the all the insurance issues we've had so far good that's marvelous thanks bob i mean we don't normally give name checks because so many people are watching but i must say that we've got a real big contingent from belgium so it must be very popular there we've got on three fde on7 qr and on4 che so maybe you know them or maybe they've just got to hear about this but i presume that direction finding is is popular in belgium as well indeed it is um in fact it was um rock rick strobe on six uh federation school who developed the very one of the very early 80 meter transmitters and his design is still being used today and uh the the event which i i'm organizing on on sunday at hinckley will be using um rick's g o n 6 y d is it i think um we'll be using his design in the transmitters oh excellent okay well um by the way if you're watching this is a recording just to set you at the date of where we are in the covid map of britain um today is a monday when the last but one sort of unlocking has happened so people can freely travel and everything else in the country but clearly this has been a hobby that hasn't been able to be done at least in the full during the covid lockdowns before um we've got a question now from g8hlu from mike he says northampton he's with northampton scouts and says is there a good source for good 80 meter transmitter designs or kits he says well i can provide pcbs for rick strobe's design and it's a through-hole um design and you can then it's all documented on the internet you can but once you've got the pcb you can buy up all the bits program yourself a pick and find yourself a box and some batteries and away you go yeah do get in touch and i can give you some more information and i guess if you are keen on the aidf but you're not maybe experienced with construction or something you're going to find other people in a local club who are and can maybe give you a hand with making it yes i mean it's there's no surface mount necessary it's entirely through-hole construction and with a little bit of practice i'm sure in any radio club you'll find a lot of people who've got hold of printed circuit boards and put components on them and produce perfectly acceptable working equipment sure kim i believe some a little bird told me that you've got some equipment there that you can show us is that right ah well this is what happens if you get uh properly hooked you end up i don't know how well you can see yeah this is an 80 meter posh commercial competition why i've got a competition one is completely beyond me but um i wanted one and i had one end of so uh it's great fun um and that's what happens you just get like everything else in the hobby you get addicted to it and i i really can't emphasize how much fun it is it really gets under your skin when you can't find the last pesky receiver i chose the word carefully there but the um sorry transmitter and and you just keep going until the bitter end and poor old bob's had to wait quite late in the past and we've uh loped him very late in the proceedings but it becomes completely obsessive so well done bob good work great fun maybe sounds like for you at least we have to add a torch to that list of equipment that you need to take well not only that i think we need a third competitor a category there's newcomers uh more experienced and then there's the buffoon class in the place off so there we go and i don't understand this word run bob here when you're talking about random getting out of breath sorry no idea what you're talking about i think the bacon bunny sounds good we're all getting older kim well you're not you're going the other way i'm flipping out gasping i don't think anything like this would be a problem for our younger uh members and people who take part so what about you flora have you got managed to get any of your friends interested in this as well what do they think um not yet but i think hopefully maybe in the future i'll be able to take some of them out and let them try and some of it but i've taken my sisters that have done some of it before as well good and i mean is it something that you really do enjoy isn't it it's not just something that you you've come on here just to sort of impress everybody i mean this is this is a hobby that you you know you your dad assures us that something you really like enjoy doing yeah yeah definitely good okay uh graham has uh said he's just found a book that he got in norway in 1975 called scout radio orienteering by nick la5ch as a long time ago but great fun taking part yeah and age age is not a a restraint um it's it doesn't matter how old you are you can still go out and enjoy it so don't write yourself off no there's several people as well compliments to all of you by the way for your presentations tonight um john m says thanks for getting me into the sport well over a decade ago that was john m zero ojm i guess you know him indeed i do is it something i guess you know in these times when we've been used to being rather isolated and just talking to each other on the radio or using other modes maybe but is this maybe something as well that's an ideal part of the hobby to sort of get out there and get to know people and and and sort of rebuild those friendships and things is it that sort of hobby yeah it's a very interesting point actually david um seeing people face to face yes talking to people on the radio is interesting um but outside of direction finding it's only the convention and the ham fest that people have generally have and the local club that people have the opportunity to see each other face to face and this is another um i do say to some of my other committee chair chairman um that at least i see most of the participants the active participants face to face quite regularly and that's not true of of many competing committee chairmen no absolutely not well you've been very inspiring tonight all of you um and we haven't got many other questions if you have got a question do please ask it very quickly now we had someone comment now um onl2108 oh sorry owen6hi uh rick owen 7yd designed the transmitters he said that's correct that's the one i was trying to refer to when i was desperately trying to remember his call sign and the transmitters which i'll be using next sunday are rick's design on7yd um it lives on today it's it's got a life of its own another question from neil g3 ir rir can you explain why you initially had errors on tx5 transmitter 5. why i had errors well that's what he said i think um oh i see i'm on the bear why the problems i guess the you know what so that we can learn from you know what was going wrong there i think it's not so much an error but merely that on on two meters the um the the range of results when it's done by hand for example i i have you have to judge when the signal falls off by roughly equal amount now are you actually when it's falling off to the left is it that exact same level that you judge it to be falling off to the right and you then take those two points and then you have to bisect them by i that's not very accurate either so and then of course you've got multi-path as a possibility that there's something reflecting the signal and therefore you're not getting a signal from the true direction of the transmitter the signal is reaching you from a different direction and that's that's completely unpredictable uh and you just have to accept on two meters that the results that you get are going to be um only okay-ish they're not as sharp as they are on 80 meters but as you get closer those errors become less significant and of course you you're able to find the hidden transmitter at the end so like lots of things i guess practice is perfect indeed certainly practice makes you better yeah uh martin g zero gmb says is there a younger age restriction in other words could i take an eight or ten year old grandson on an event well we have a family um from birmingham who do it um and their two boys who i think are i think the younger one is is just started primary school and the older one has been at primary school for a couple of years so they must be seven and five um they go around with mum and dad and the kids have great fun when they get close to the transmitter as navigated by dad with the receiver and they're able to rush off and find the hidden transmitter and punch the box and so on okay yes kids of that age providing they're accompanied by their parents and can do it and and can have some fun doing it i'm sure they'll have lots of fun uh wolfgang dl1bjv says are there any competitions where teams of two or more competitors are involved um the short answer is not not in the iaru rules the the three formats are the classic race um and the foxo and the sprint now teams are formed by summing together the performance of individuals doing the same course in parallel it's not never done as a relay sprint competitions are done as a relay but the classic competition is not and things like the world championship european championship and so on they are the the team events are classic races with the the teams doing it in parallel with each other and aggregating the times okay well i think that's all we've got time for tonight but i'd like to thank you all once again let's have another look at you that's uh to bob kim and to flora thank you ever so much for tonight i think you for sure that you've inspired other people to have a go with this wonderful part of the hobby thank you very much aaron i'm going to leave you with one comment actually which came in a bit earlier on from tui 2m1 cjl bob and it says can't believe i'm only discovering now this side of amateur radio it looks like great fun and he's looking forward to it and lots of other people have said something similar so well done to all of you to bob kim and flora thank you very much indeed for tonight bye everybody and don't forget we did mention this book it's available for just under 10 pounds from the rsgb shop now if you want further information at all but that concludes this webinar and thanks once again to our guest laura jolly kim m0knv and bob g3ory we hope you've enjoyed this tonight today and you'll join us again next time and we'll be getting an introduction to meteor scatter communications if you'd like to see details of that and other webinars or to send any comments or feedback please visit rsgb.org forward slash webinars and remember if you subscribe to the rsgb's youtube channel you'll also be notified of all upcoming tonight at 8 webinars as well as other new videos and presentations from the society on a wide range of amateur radio topics but until next time this is david g7 erp signing off and clear bye [Music] so [Music] [Music] [Applause] [Music] you

Channel: Radio Society of Great Britain

Views: 1,264

Rating: 4.8974357 out of 5

Keywords: RSGB, Radio Society of Great Britain, amateur radio direction finding, ARDF

Id: ZuLkRdisXco

Length: 79min 5sec (4745 seconds)

Published: Mon May 17 2021