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Fieldcraft Radio Direction Finding

Sean the Nailer

Sergeant
Full Member
Minuteman
  • May 20, 2006
    6,773
    10,382
    Winnipeg, Mb.
    @Gunfighter14e2 what do you think of this?
    http://theleggios.net/wb2hol/projects/rdf/tape_bm.htm

    I ask because of the very 'low cost' to build, as well as the implied 'ease' of storage. As opposed to something that needs a wall/shelf of it's own when not in use. I/we have some Blessings coming our way right quick, and I'm thinking of expanding as much as I can. And I just thought that this was interesting in itself. Both as a project AND as a tool.

    Thoughts?
     
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    Yes that will work for you. I use cheap Harbor Freight tapes for quick set up an take down radials. The free ones you get when buying "anything" else with the 20% off coupon.

    The Yagi design hand held works good for RDF as that is what we use/d in the field to locate the interfering an often illegal source. One word of caution when building one for TX vs just RX all elements lengths need to be perfect or the SWR get out of hand quickly.
    HTH an good luck
     
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    This link is to a device that can help in many areas has it has some good radio if as well. They sell out quick so if you want one, you know.
    Back to the antenna. My first Yagi beam was just outside the shack window at about 40 foot. I made a 3 foot wood circle that was a fixed to the fiberglass riser. A clock type spring was a fixed to the circle an wound tight. Then a chain was a fixed an run to the window where it was marked each 3* and could be hooked. The hook was adjustable from 0-4 degrees. Worked will until I built what my beam is on now. Many ways to skin a radio cat with little to nothing once you think out of the box. Much like tuning a home made J-pole with a file to get it perfect. Another thing that works well is a home made Wfi reciever if you have local free hot spots. A quart bean can with the RX antenna inside, you can draw in low power signals an deflect the stronger real quick. A bud was having issues an now locals come to his home to use his computer. Ham Radio teaches far more than just CW (Morris code) if folks really want to learn. In electronics the impossible only takes a little longer to achieve,....LOL
     
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    STN,
    You might want to research, copper tubing or aluminum an PVC for making your own Yagi if your going to put it in the weather for very long. Many different designs out there depending the end result your looking for or willing to except. Also remember the feed line is part of all TX antennas. RX only not so much, but you can make a very good RX/TX antenna just using old Rg58 an a soldering iron, or pinning it in the right locations. Many people scrap 58 do to many issues, yet it still can be used in building an antenna array.
     
    STN,
    You might want to research, copper tubing or aluminum an PVC for making your own Yagi if your going to put it in the weather for very long. Many different designs out there depending the end result your looking for or willing to except. Also remember the feed line is part of all TX antennas. RX only not so much, but you can make a very good RX/TX antenna just using old Rg58 an a soldering iron, or pinning it in the right locations. Many people scrap 58 do to many issues, yet it still can be used in building an antenna array.

    What GF said!

    I used to build antennas on a regular basis at work and for fun. I really liked using copper water pipe. Was much better than the usual published plans using AL welding rods. Spacing will be different, but it was worth the extra time tuning it for me.
     
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    STN
    This link should help you as will the other links therein. The ARRL has a very good antenna book an most of them can be built with what others discard. We had a bet one time about the cost of building a tower, rotor, an hex beam. Long short it was 60foot AGL covered 30 to 6 meters an less the feed line, as 11.00 Dollars US, working.
    Always think out of the box,...
     
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    WOW! Very creative. Don't think I could have done that, even close.

    I did get towers for free for taking them down.

    Most of my antennas, except for mobile, were homemade.

    Bunch of verticals made from 1/2" copper water pipe on top of a 36'X96' metal roof. Five acres of fence with a hot wire that was mostly a loop or long wire. Made some "secret antennas" that were clothes hangars with a coat on them. One Yagi with copper water pipe, 2 mtrs.

    GF we still need to try HF one day. I did put up a 30' tower for "free" TV. Amazing how many people think you have to pay for it. Love the commercial that says the FCC MAKES the networks transmit for free and try to sell a little antenna what works for a crazy distance.... Anyway, might set up a station again. Bought a new truck a couple years ago and took out the Icom HF/Vhf/Uhf radio and ant tuner. Probably should spend a day and reinstall in the new truck. Just never drive far anymore.

    I might be flying to Mobile in a few months, we could try a Vhf simplex freq. Not sure where you said you were, Huntsville area...

    Don't forget to visit if you get to the Houston area. Bring guns and ammo!!!!!

    Enjoyed your thread on tracking several months ago.

    73
     
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    s.GF we still need to try HF one day.
    Just let me know an we can do it. If I'm driving I can do all bands in no more than 5 minutes max, 20 an down about 1 minute. Have 500 + chipmunks (1/2 a bucket to some)to draw on if needed, course mother-nature will get the last word. Can do SSTV an all digital from the truck as well. If at the QTH any band (as long as my beam is up) any band/mode in about 30seconds, with a Bucket + if need be. If the beam is down do to weather, about 8-10 minutes an we are good.
    The tower bet was interesting, an the new guys learned you don't have to buy much of anything if your patient, an have a few skill sets.
     
    s.GF we still need to try HF one day.
    Just let me know an we can do it. If I'm driving I can do all bands in no more than 5 minutes max, 20 an down about 1 minute. Have 500 + chipmunks (1/2 a bucket to some)to draw on if needed, course mother-nature will get the last word. Can do SSTV an all digital from the truck as well. If at the QTH any band (as long as my beam is up) any band/mode in about 30seconds, with a Bucket + if need be. If the beam is down do to weather, about 8-10 minutes an we are good.
    The tower bet was interesting, an the new guys learned you don't have to buy much of anything if your patient, an have a few skill sets.
     
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    Thank you Guns, I'm working on a few different tangents at the moment. Hoping to meet up with a few fellas this morning, to help me get 'up and running' on a few portables that I have here now. May even talk about this mast that I/we have here, and see about setting up some sort of HF system in the future. Not getting my hopes up, and taking small bites/small steps, but definitely moving in the right direction.

    So much interesting stuff, and the doors in the hallway are creating access to so many different tangents. With the HUGE help of another member here, I'm actually in the process of 'walking down that hallway' now. YAY.

    I'll keep you posted.
     
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    This is what we've put together so far. I still have to pick up some cable and some 'ends' to connect to different hand-helds. Figuring about 6' of cable, or for those who've used these before, what do you suggest? 2', 3', thoughts? Just trying to make it convenient to use.

    Going to put an 'end' on it, and seeing as I have two different portables (and each have different antenna connections) I was going to make a 'transition piece' for each of them. Is there a 'standard' antenna connection for me to think of using, and then make up little 6" 'transitions' or whatever, to match whichever radio I'll be using this with. Now and in the future?

    We've a Yeasu 6 here, and a Feng 5x so far. One day we'll have a mobile and a marine and a base/tower. Point is, I'm trying to make this antenna as 'ambidextrous' as I can. As opposed to 'dedicated'. Simply because, I've no idea which radio I should dedicate this to, IF that were to be a good idea or not. I don't even know that answer, hence why I'm trying to make it work for everything now, and in the future.

    7046882


    7046883
     
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    2.5'-3.5' works good.
    I'd do a BNC on the coax then get the correct SMA/BNC for the transceivers. Looks good so far, just make sure you get a good connection to the steel tape an you should be on your way. Have you ever hunted hidden transmitters before? If not there are some good fox & hound videos on you tube. One thing some don't point out is once you get real close or the signal is strong an bouncing off local stuff, move the VFO slightly off freq an the receiver will not get over loaded. Much like narrowing your receive beam to a pin point RDF.
     
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    Soldered this all up last night. Hoping to connect with someone local here, that knows more about these things than I, possibly has a SWR meter (that's what it's called?) and is able to give me a hand to test/tune/tweak this project.

    I'm hesitant to connect it to my Yaesu yet, as I know that I don't know what I'm doing, and I REALLY don't want to fry anything. Only antenna connection I've got so far (from local supplier) is for the Yaesu radio. Do have the BNC connections though.
     
    These tape measure Yagi antennas work great for direction finding and focused transmitting. I've made HT to HT distance connections where standard hi-gain whips will not even clear the noise floor on open squelch. That connection was using the Yagi on one side where the other had just the hi-gain. Adjusting the polarization horizontal vs vertical orientation will also help cut the signal reception and going slightly off frequency will help cut too for narrowing down detection signal azimuth.
    The wound coax taped over choke was suggested if being used for transmitting at the time we made these antennas. Instructions were pulled some web found instructions. I still think about picking up a semi-commercial made version too.
    IMG_0770.JPG
    IMG_0796.JPG
     
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    Tangotag
    Very nice job on radius'ing the ends, that is an area that is very important.

    Yea the wound coax makes a good RF choke, encase RF is running the skin(coax). Most HT's even set to high with the SWR way off will not bite much at all. A base station running above 25 watts will get your attention though. However if the antenna is 50 ohm at the feed point the odds of RF running the skin is low if it's fed with 50 ohm feed line. The other thing you can do is add Ferrite's either before soldering or the ones that snap on thereafter. I like them before with heat shrink right at the feed point, makes a more compact package.
     
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    No, not yet. Still trying to connect with someone that A- has one of these meter-thingy's and B- knows how to drive it.

    I can physically connect it to my radio here, but seeing as I don't know what I"m doing, I REALLY don't want to fry anything or 'let any smoke out'. So I'm just being patient and trying to connect with a few different guys here whom I've been "pointed to".

    Their schedules and my schedule hasn't worked yet. But I'm patient. It's sitting right here beside me as a constant reminder.

    I'll put some pictures up, to show what I've done so far. Some of these other detail 'just released' would have been good. They'll probably have to go into 'phase II' of the project now.
     
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    I would say! Was it WX related?

    I am keeping my promise to get back on the air. I pulled out my Icom 706MIIG and found the display is barely readable. After MANY hours research I found that the IC 7000 is even better than the 706 and the new 7100 as well as about the same cost as repairing my 706. SO I have one on the way, BUT I need the separation kit or at least the cable for the install. Another many hours research and talking to Icom ect, they have been discontinued and the connectors we only used on the 7000 so connectors can't be found to make my own...

    I was was thinking a little of maybe going and looking for the cable at the show. Too bad you can't hire a private shopper although seeing all the new toys would be fun.

    Steve
     
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    I UNDERSTAND! I have a little in the toy fund, so looking to get some radios back in the house, truck, and ranger for the shooting range. Also going to set up a friend with radios for his ranch.

    I see I just missed the big Houston HamFest... Might go to Texas City next month...
     
    My next big one will be the Huntsville Al. show, it's always good in every respect. The tail gate section is inside (w/ a/c) and it's huge. Lots of NASA an three letter types always there. Never been to that one, that I have not learned about new stuff/ways to do a few things. All the larger mfg's, with their eng'ers to answer any questions or run an idea past.
     
    When will that take place?
    I would like to go to a event like that. I am so outta touch with new features ect. I have been in and out of Ham Radio since 1976 maybe? Before I could drive. I am a couple decades behind on the new toys. Used to be able to tell you all the differences between the three major manufacturers and the classic equipment like Drakes ect. Not any more....
     
    When will that take place?
    This Link has the info. Huntsville has a good place to land as well, only a short trip from there. Beings Redstone is there, at times there are a few flight restrictions, if your behind the yoke. If it's RF anything it will be there, an somethings ( but very few) none RF as well. Never been that I did not learn about something new coming out or how to put a different twist on older gear. Let me know if you can make it, as it would be my pleasure to meet you. Saturday is my normal day, an depending the presentations, I take in one or two, depending subject/interest.
     
    thank you. If I go, I will certainly fly. If the WX is good can visit with you on vhf/uhf from the plane. I'll make it a Sat if I can go and take you up on the ride, thank you!

    FedEx has delayed my new toy, IC7000 for another day.....

    Probably need it anyway to decide what ants and mounts I will use. Last truck had the ants on a headache rack, but this truck is too tall to get into the garage with a rack, unless I make it, yet another project... Used ham sticks and an AH4 ant tunner. Thought that was a great place but reading that it is not and that ensuring all parts of your truck are grounded together is NOT BONDING.... So never heard of that.. So many new things to research....

     
    It took me 2 full days + to ground my gray Nissan when I installed the radio, an peripherals. Well worth the effort, but lots of work. Kenwood TS-480sat, ALS 500m amp, ATR 20 tuner, with 2 groups 29 deep cycles for the comms only that are only tied to the trucks DC system when the truck is running, no way for the radio to run the cranking battery down. I also installed a remote charging port that I plug into using a 100amp single wire GM alt being driven via a 6.5 hp Honda (that does everything required even with the amp at full power) at 1400 rpm. It is so nice to have that set up so not to have to run the trucks engine when parked. There is no hash from the engine but I dislike running it, the reason I installed the extra battery's for longer ride threw if needed, as the Honda is quieter than the V6 idling.
    Lots of work to ground a truck to a single report point as I did but well worth it. Some new vehicles are mostly fiberglass shells, so that requires a different approach similer to what I did with the camper shell on the Nissan.
     
    Putting the truck together as a station was an effort but it has paid off over an over. It's an older truck but is my do all, e-comms, range, work, play, ect. After I put the fiberglass camper shell on, Went to mount a CB style spring mount to holed the Ham-Sticks, but did not like the fact it would be mounted to the fiberglass w/o a ground. Thinking about it, took my pocket meter to Lowes an Ohm-ed the foil duct tape. The cheapest one was the best so I got 3 rolls then went to find bare copper wire. They had spools of 18gauge so get two of those an headed home. Took the copper an hooked it to the single reporting radio ground an used the foil tape to hold it in place on the inside of the shell. Found I could span 8" before the Ohm meter read 0.01 resistance so now the whole underside of the shell is lined with the wire an foil. Mounted the ant base an then made it report to the single ground as well. Installed a MFJ 1979 an turned the 480 to 20 meters. the ant in on the left side on the shell about 12" back from the front of the shell an about 6-8" above the truck bed. Checked tune an it is a flat 1-1 from about 13.854 to 15.252 I was shocked to say the least. Turned the power to 50 watts an keyed up in a QSO was listening to get get a check an one guy was in Calf. the other in Montana. They both came back saying a 5x5 to a 5x7. They seem to be interested in the set up so turned on the amp, set it to max an keyed up again now it was 5X9 an 5X9 with 15 over. To say I was happy was an understatement to say the least. The added ground plain made a huge difference to the trucks ability. Also carry a grounding plate with wire that I throw into local ponds/lake that adds as well. Most of the good remote parking spots have water near by. At the local range there is a stream that you have to cross over that work very well also. The range is in a valley but the Ham sticks work well that low of a AGL an get a lot of NVIS effect which is perfect for e-comms plus the 20meter set up has lots of reach for nation wide info.

    The truck has been used many times for local group/s(alike thinkers) E-com training (none ARES/RACES)an from parked to full operation on 70cm, 1.25, 2, 20, 40, 60 & 80 meters only takes 15 minutes total, which includes the Honda running if required. I made a antenna head the holds 6 ham sticks (3 band dipoles) that works perfect just like a fan di-pole. It sets at about 20-28' agl on military fiberglass poles the MFJ 1979 is mounted into the CB mount, an the antenna for 70cm -2 meters is a mag mount the sets in a pizza pan at 18' agl. Run a VX6R on that antenna an carry 2-3 baofeng BF-F9V2+ w/ pryme AL 800 antennas to mon all UHF freqs used. Also have a lap top an Signalink to send digital or SS/FS TV if needed with a digital camera to send photos if required. The 500watt amp was installed just for the SS/FS TV but I have found other uses for it at times as well. I also carry a portable 1/2wave 80 meter NVIS set up w/ reflector wire if mother-nature really wants to play. With that setup an 500watts I've never had issue to a 125-150 mile radius to date in the worst she as thrown at me. I would really like to find a 4X4 van some day an move all the gear into it, as I think the added space would allow for more interesting items to be played with as well as enhance some endeavors, I see coming down the road.
     
    SOOOO rather than continuing this on StN's thread, should we start a new one? Sorry Sean if I have broken etiquette.
     
    No worries Stevo, I appreciate the learning. I have SO MUCH FURTHER to go, to get to the beginning that it is crazy. But reading all this and trying to make progress locally and juggle life. It's fun.

    Now Guns, what I hear you saying is that you want to build the "surveillance van" from the beginning of True Lies, right? HA.
     
    Now Guns, what I hear you saying is that you want to build the "surveillance van" from the beginning of True Lies, right? HA.
    Not really but have ideas on how to put a twist on a few things. Mostly for comfort of being able to watch more than one monitor at a time an patch all the freq's being used together if required. As well as being able to be sending SS/FS TV while doing another task/s at the same time. It would be nice to be able to tap Sat's as they pass by an up-load for a dump where ever you want an receive their info/replies back next orbit. With Sat's it matters little what mother nature is doing but time becomes a factor with Ham-Sat's.
    Yes, a rolling chair an a snack bar would be nice,....:coffee::love:
     
    No worries Stevo, I appreciate the learning. I have SO MUCH FURTHER to go, to get to the beginning that it is crazy. But reading all this and trying to make progress locally and juggle life. It's fun.

    Now Guns, what I hear you saying is that you want to build the "surveillance van" from the beginning of True Lies, right? HA.

    I actually did. Nothing like Hollywood where you could see through walls ect, but the latest greatest in the mid 90's.

    Because of my experience in playing with ham radio since I was a kid I was able to piece some equipment together that other agencies never thought. Nothing really high tech, just using equipment they had not thought about. Another ham would have done it if I had not.

    Fun days!
     
    Great job!

    Well I am not going to go as far as you did, don't have a camper lid, don't want one. I was given a light duty headache rack yesterday. I have been cutting it up and welding on it. Making it fit on my truck and low enough to get in the garage. I modified my garage door opening so I could get my truck in. It clears by less than an inch. So as you know most racks are taller, then ant mounts. So making this on a couple inches lower and different way to mount to the truck tool box. Going to run the station the way I have the last two trucks, mount a VHF ant and a mount for HF. The HF mount will have an AH4 tuner and I will change out ham sticks for the different bands. I will certainly have to take the ants off before pulling in the garage. I'm running a IC7000, so I will modify my sunglass case I never use, and place the control head in there. Place a remote mic jack in the console and place the radio under the console with a fan that comes on when the radio is on. Will bond the headache rack, bed, cab, frame, and hood together. Run test and see where I need to go when I get there......
     
    Another option is have the ants tilt/hinge back & down to enter the garage. I have seen many that were motorized & when up a LED was lite on the dash. A flip of a switch an they lay down. I built a motorized screwdriver set up for a guy that did that an used a 12Vdc cordless drill I wired to the truck. Put a DPDT switch on the mic, he could raise an lower it an he got good enough later on to do it by ear. He'd then key up an look at the SWR an fine tune if he wanted it flat. Used a manual Super-Antenna an it worked as good as a TarHeel, while saving the coin for other trinkets.
     
    I have thought of a motorized unit. Had one YEARS ago, don't remember what happened to it, but sure it was bad or I would still have it. Might see what is on the market today.

    While thinking of ways to remodel the headache rack I thought about using a pipe for the top rail and allowing it to turn 90 deg. I would use a bonding strap to keep good ground and a pin to lock it in place. LOTS of ideas! If I tried to use them all I would still be building/installing next year. Have ammo to load and guns to shoot!

    Finished cutting and welding today. actually sanded and wiped with a pre painting cleaner and found out that the cans of primer I thought I had were cans of grey paint! So after shooting tomorrow, painting and installing the rack. THEN I can start on installing the IC7000. Hope you might be my first HF contact in over 3 years...
     
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    Let me know an we will do it. Storms here this weekend but as long as lightening is not very, very close I still work the rigs. Depending mother I'm thinking 20 for phone, your thought's?
     
    Shooting today, Working at church tomorrow, separation cable comes in Monday.
    Still have to paint the rack and install under tool box. THEN I can start with the install......
    So still a few day s out, but it would be great. Yes 20 sounds good to me. Have to sort through the ham stick and see what I have, think I have one for every band.
     
    When parked The MFJ 1979 can not be beat on 20, on my truck.
    16.5' max, an with the extra ground plane the topper added, it all most competes with my hex beam at 42'.
    I have learned it's pattern an can park the truck accordingly then mod the pattern a little by opening a door/s or the hood. I'm like a stopped clock most of the time but every once in a while, the sky's part an light shines threw,...
     
    Impressive! Well I will try my Ham Sticks again and then maybe try a center loaded ant for fun. I don't have the great ground plane like you so thought that might help.

    I just checked email and saw my separation kit will be here today! So I will install between coats of paint on the rack.

    Shooting put to 800 yards today but can't see most of our targets due to high grass. When the wind blows just right you met see a head, so figure where the center is and shoot.

    I have a camera on the 800 yard, so I can see hits.
     

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