This was cool to find. I just got my GMRS and my technician license, and getting into the hobby way late in life. However, I did have a love for radio back in the early 80's growing up. As a very young boy, I got my hands on some old discarded CB radios, no antennas power or anything. I would take those with a power supply, sometimes just a car battery, some old junky speaker wire for my antenna, and I would hook them up to the tower TV antenna we had outside of the house for watching TV. I really had no idea what I was doing, I just knew with the TV you could hook a wire coat hanger up and get a better picture. To me that meant I could hook those CB's to that tower and get a better signal. So I set myself up outside and ran a wire to that big metal TV antenna. Boy, I was picking up truckers for miles and miles! I would mostly listen, being less than ten years old, not many truckers wanted to hear me talk. However, some were really nice and would engage with me. Now I'm all grown up and over the hill, got my license, got a radio, and I still feel like that little boy with those CB radios just itching to be on the airwaves again. Just thought I would share my story, because this video took me straight back to that. Thanks for filming it. This brought back a lot of memories of being so enthralled with radio. I'm stoked to finally be doing it again.
Hi Walt, That was a good experiment. Back here now in PA, there are a few old windmill structures on abandoned farm fields that now I would like to try. Some are metal into the ground; some are wooden with metal up in the air. If I get the opportunity, I’ll let you know if successful. As always, thanks for the fun video. ‘73 my friend! AC3EA 🏡
I promise you they are not abandoned farm fields. Someone somewhere owns them you should really get permission before you go so ng your thing on someone else's property
At least you gave it a try with what you had on hand at the time. Part of ham radio is experimenting with antennas. One of my fellow club members always says "If it can radiate, you can communicate." If you aren't in the area long enough to get the supplies needed to turn that tower into an antenna maybe you can have them with you on a future trip.
Another thing you could try is some type of capacitor in the lead feeding the antenna. I know the rig has an autotuner but perhaps a good variable capacitor one could "peak" the receiver on then try to load up.
Suggestion; Since you really don't know what the feed point impedance is, take an analyzer with you next time then use a transformer closer to that range, as checked at the FEED POINT. The 1.2:1 SWR isn't the best measurement for effective antennas. Sand off the connection point at the tower if you hadn't, and at different heights (that tower just might be grounded since it's really a robust lightning rod). If you're close enough to revisit the park again, this might be a real good mini-series!
That was fun just watching you load that up. That was more than 1 wave length long . I wounder how much RF went into the ground . I would have tried 40/80/160 meters. You know know that a great RX antenna. 73's
4-sided tower. Maybe the other 3 legs created a “parabolic” or reflective “bowl” so to speak, and sent your signal in a direction not wanted?? Just a thought.
I have the exact same problem using your Coastal 20 antenna on 10M. It kicks ass on 40, 30, 20, 17, 15, and 12M, but nobody hears it on 10, even though the swr is easily matched by an antenna tuner. Maybe it's the angle of radiation?
The only thing I can think of is a Gamma match to the tower leg. No idea how long the tuning bar would have to be. Might get arrested too. The other idea 💡would be to throw a line as high up as you can and pull a random wire up the middle, feeding it accordingly. Nice attempt and the receive was awesome. 73 de N4SHO.
Some years ago, we were in Dublin and I'm looking at the 120m tall 'Spire of Dublin', thinking how do I match and load this thing without anyone noticing nor taking offence.
Great effort Walt. I'm very glad you tried this. I think the issue here is you are feeding a signal into a near dead short. The bottom of the tower is grounded through the rebar in the concrete. I know it's not possible, but if you were to connect that feed wire up about 1/3 of the way on the tower, you'd have different results. Think of a yagi and how a gamma match feeds the driven element. The middle of the element is at ground potential, so the gamma is connected at a point away from ground (center) where there is some impedance that will accept power from the line. Also, the 9:1 may have been working against you. The feed impedance is perhaps 1 ohm where your connection was made and we're dividing that by 9 so the coax probably only sees 1/9th ohm impedance. 20 watts in may render 0.001 watts out. The best part of this experiment is that an antenna may hear exceedingly well, but that does not mean it will radiate equally well. Keep up the super work bro. 73 OM
@@joewoodchuck3824 You are correct, I can not tell because I was not there and did not build it. I should have said, "The bottom of the tower MAY be grounded at RF". Clearly it was an assumption on my part. Even If there is no rebar or other metal structure within the concrete footings, it is likely that there is an impedance path at RF frequencies at the footings which is helping to bring the bottom of the tower closer to electrical ground instead of isolated from it. Most freestanding towers used for AM broadcast were predominantly shunt fed for this exact same reason. Only those that are sitting on a porcelain insulator are series fed. Hope that answers your question. 73
Even it is was actually say 20 watts into the structure, my mind goes to how much of it there is mass wise and the steel resistance. I appreciate that AM stations do put KW in structures, but am I right in thinking that signal would ...I am tempted to say absorbed into the mass? Like feeding 20w into a copper wire vs Steel bar. Thanks Tim VK8LLA
@@mowtown75 Hi Tim, great question! From what I've seen and learned on the job, the skin effect definitely plays a part in how well a conductor radiates, but only when the frequency is very high and not at MW. The "mass" of the tower doesn't play a role here. The tower is just a conduit surface that the RF can ride on to generate the H and E fields. The thing is, the resistance that I think you're asking about is all in the skin effect on the surface of the tower. At MW frequencies, it really doesn't matter like it does at UHF and up. At UHF and higher frequencies, the surface must be very smooth and greatly benefits from a silver electroplating. It's all about the radiation resistance of the structure. Generally, the higher the "radiation resistance" (not to be confused with DC resistance) the better. In this case, the "Rr" is so low that the material of the structure and/or the surface condition or coating is such a small percentage of the total, it can be omitted. All MW towers that I've worked on are painted and most have serious surface corrosion under the paint, so the iron in the steel really doesn't play a part in affecting the RF. IMO, the significant reason why this particular tower would not accept power was due to both the location of the feedpoint, and the fact that there was no proper groundplane below the tower for the RF to push against. If Walt were able to connect a 3 wire skirt somewhere about halfway up the tower, then it could be fed as a "folded monopole" on perhaps 160M and 80M, and have a much better chance of accepting power due to a higher Rr (provided of course that there was a proper groundscreen below) At the higher frequencies, the tower would act like a vertical Beverage. There would be two main lobes from each end. One would feed RF directly into the ground while the other would place the main radiation lobe straight up and be a "cloud burner" because it's much too long for SW. There would be some minor lobes at very high angles, and yes it would make some contacts, but the majority of the power would go up to the heavens. Tim, back in the really old broadcasting books (1920's) I recall hearing of a weekly wipedown of the SW antenna wire by a newly hired technician. The purpose was to remove oxidization on the exposed wire which was usually made of phosphor -bronze. I'm not sure how successful this weekly chore actually was, or if it was more of a probation ritual for the tech to "pay his dues". At SW, I don't see any electrical benefit. Great discussion. Keep thinking about antennas! It's a wonderful exploration. PS. If you haven't seen it, watch "Standing up for standing waves" (just paste that into the search at the top of YT). The video is a rebroadcast and is presented on the KN4AQ channel. It is one of the best demonstrations on traveling wave theory and worth it's weight in gold. 73 OM, de Hollywood 🎙
When I was getting my technician license a long time ago, the Elmer loaded up a metal stool that was in the classroom and was able to make a contact on 20 m. Pretty dang cool!
That's a great idea! Using old abandoned tower for an antenna! One thing I thought that could make a difference possibly is to clean the contact point on the antenna tower. I would sand/grind a clean contact point for connecting to it. All that scale and crud on the surface may attenuate your output. Just a thought. I would like seeing a follow up in the future with mods to the tower antenna experiment.
Nice…! All you need to do is make the ground resistance higher (shunt feed) and it won’t act like a dummy load my brother… very cool to see folks tuning up random stuff
@@1crazynordlander haha.. Those towers are great.. We did a old WInd Mill tower a few winters ago.. It worked great.. i worked Steve in SC ko4gms on 1 watt.. Probably just a lucky day, LOL..
I would have used some scotchbrite to clean the contact patch on the mast.Was the G90 set to 20 watts - bright sunlight can fool the eyes lol ? Maybe get Calum to model the radiation pattern lol. It's all about the fun in the end Walt - I have spent endless hours on my newly aquired Black Brick qrp sdr transceiver including insde of it. The tinkering alone is entertainment. 73 M7BLC
Great experiment Walt. I had very similar results when I tried tuning up a farmers fence. Great receive but hopelessly inefficient on transmit! Wondering if the tower might be grounded for lightning protection (other than through the concrete)? Either way, it was worth a try & made for an interesting video.
Receive is microvolts. Transmit is volts. Your tap point on the tower is a short to ground at the volts level. Get those transformers out of the circuit - this is a low impedance load, not hundreds or thousands of ohms. Stay back 15 or 20 feet and run a sloping wire up the tower leg as far as you can. Remove the counterpoise wires from the tower and connect only to the ground lug on the radio. Had you done that "maybe" they would have heard you. Try it again. 73
VK3YE tried this with a 100 foot light pole. He actually brought a manual tuner and wrapped several feet 60 feet of insulated wire tightly around the base of the pole...and operated it like a transformer...or an Inductor... worked well. try it again after watching his video. This is the title to search.."Trying a 28 m light pole as an antenna on 3.5 MHz"
I'm not an amateur, just a shortwave listener, and this looks really tempting to try. If nothing else, a bow and arrow to take a long wire up there would be neat to try. Might have write off the wire if I could not get it down though, I'm not climbing up there to get it back, ha ha.
We have some abandoned fire towers scattered around Northern Ontario Canada...they are all 99 feet tall. Thought of climbing up with a radio and dropping a 62 foor vertical with a 49:1 balun off the top. (these towers are REALLY remote) VA3IRF
If I tried this over here I would be arrested. No joke. Mixture of health and safety, jobsworths, and national security issues. I got reported in the late 80s as a potential Soviet spy because Morse was heard coming from my car.
Thanks Walt: it is nice to see that every of your activations do not go as plan. It makes you more ham real!!! Same thing happens to me sometimes! ke9le 73
That was fun! I follow K0KLB on RU-vid and see him connect to some crazy farm implements and structures. I connected to an insulated electric fence surrounding a quarter section of DNR land behind my farm. I did this before the rancher that rented it and electrified the wire. I was able from Western Minnesota to make contact with a friend of mine in Oregon that is a control on the YL System. I heard you try and contact Rick from the YL System and Art later. Art usually hears everything. Thanks for sharing. I wonder if I have ever made a contact with you. I'm KA0KAE Kevin
@@BKHD605 Could use a hook or "tie a knot", I've done it with trees. You need skills operating a drone. Drones don't have long battery life, you couldn't HAM for too long while just holding it there. Also difficult to call CQ while flying a drone...
Actually, I think that you have a good idea there. But I THINK that what you need is what they call a "shunt feed" to do that. I'd love to know if you found anything on that, and let me know! All the best! 73 DE W8LV BILL ("good in the book" as they used to say when we used the "Flying Horse." 🤣
I’ve done this experiment and similar about 30 years ago. Shunt feed it. While I was still Playing with the gamma tuning I accidentally made a ssb contact and subsequent short QSO with Bermuda on 160m. The tower was a Rohn 25 at only 80 ft with a TH-7DXX on top. No ground system but the grounding rods on each leg. Otherwise that tower is only useful if you could climb it. I’m gonna guess that’s not an option. I always thought that a much larger tower shunt fed would be very interesting. Later in my career I worked for the navy and had access to a 1200 footer. I always dreamed of making a shunt feed for it. Never did. I do applaud you for your efforts.
Ok , I hear your problem . THAT TOWER IS GROUND . Your mission , should you choose except it is to get a RADIATING ELEMENT to the top of that tower . UNDERSTAND , the two parts of your co-ax must be SEPARATED . Weee doggy , you’ll beable to get out then by golly ! The FCC has rules about how high your antenna is allowed in height , but man ! You will be king of the airwaves then !
It would be interesting to know how disconnecting the vice grip affects the SWR. I wouldn't necessarily trust he metalwork joints in the tower to be conductive. Concrete, on the other hand, can be surprisingly conductive. A proper shunt feed would use two connections, on at the bottom, and one higher up, and would be low impedance, so even the 9:1 is going the wrong way. Another possible feed would be several turns around the base, though that's a pretty big base. It's pretty tall: did you try 80 or 160? Happy field day.
Hey I do it same not abandoned tower but near radioclub tower was almost exact same and well grounded. So 1 wire I connect much more high. Some ⅓ hight from ground another wire on grounding bolt. First wire I connect anoter side to old Dentron antena match on single wire terminal. Second wire I was connect to GND terminal . this wires work like delta match. And need to be on some heigh not just 3-4 foot. Impedance is too low. Transceiver what I was used was Atlas 210x Same idea you can find in book all about vertical antenna. It is proven. Tower and delta match it work. If tower is well grounded work better. Everybody around me told, huh just wire radiate but no all tower work like radiator. How exlpain 59 on ssb and 599 on cw over 1000 kilometer distance. Find delta match and connect wire 30 feet high.
I wonder if you had a bad connection to the tower. I'm sure they'd frown on you sanding a spot to clamp the wire, but that may be (part of) your problem. If so, you may have just had an OCFD with the long leg on the ground. Cool experiment. Who hasn't looked at a tower and wondered if they could tune it up ;D
A bit of simple trigonometry would give you an idea of the height. A protractor, distance out from the base and I forget which, but sin, cosine or tan would give the height. G4GHB.
Obviously, the tower is grounded. The ground loss is so high its ridiculous. Tower needs to be isolated from ground. A low vswr means nothing! A dummy load has a low vswr. Pshhh, elementary antenna 101.
It would be interesting to put a nanoVNA on that tower to check what portion of the impedance is radiation resistance. SWR can be perfect, yet performance can be terrible. Just try transmitting on a 50Ohm dummy load.
I'm not an expert of any mean but I think that such a huge structure needs way more power than the 20 watts the G90 provides? For a reason broadcast stations run killowatts? Its not the same 20ga wire vs a huge chunk of steel. Also thats why you reception its amazing but the power get lost before getting out? I will love to try that again but with an 100 watts at minimum like the FT891 or something similar. Dang it, now I am looking around for abandon towers lol. Thanks for the video.
walt...try wrapping your feed point with heavy alumium foil and then clamp with the pliers. that should provide a capacitor at the feed point that may work better then the pliers alone. ken WB4AKK
Great experiment in portable ops plus no one walked up to or into your antenna! I will be up there in July for two days and plan to activate a park with my KX2 on CW. Perhaps I'll give that tower a try. Also, I need a recommendation for a good place to go for a lobster roll...thanks!
The tower height is not that important here. But if interested one could determine by counting ladder steps. My very ROUGH estimate is 75 to 80. due to combining different shot angles.
Well the first thing is the tower is not insulated above ground so you can't use it as a series of vertical however you can shunt feed it. This is done by taking a climbing up the tower anywhere from 10 to 20 ft and attaching your wire at that point. Then running that wire a quarter wave away from the tower at roughly a 45° angle. At that point where the wire now meets the Earth is your ground point. That would get the other half of your coax you are a fan meter goes in between the center of your coax a large variable capacitor in Ceres and then the wire leading up to the tower. My adjusting the capacitor you adjust a coupling and the slope radiator connected to the tower acts as an electrical shock feed and usually you try to do this at a certain distance that creates 904 degrees but since you can't calculate it you can pretty much guess about 20 feet
What I do when I get to work early as I use an LG 9:1 an alligator clip it to one of the light poles in the main parking lot with an 8 ft of counterpoise and I'm able to to qso with WI
🎉 Any chance you formed a high impedance connection for transmit? I don’t think speaker wire and vice grips are going to cut it. You need to bond to that tower better in order to radiate.
If you could find an obscure spot, could you drill a hole and tap it for a bolt with two nuts? You could sandwich a connector between the nuts and have a great contact to te structure. Doug
all your rf was going to ground if the tower ws insulated from the ground it would have been epic u could use the tower as an rx ant and a verticle ore resonant ant for tx nice idea though
Got a friend here n Palestine tx who stop by the nat armore ask if he could try to hook up his ham radio to a army tank for a ant they said yes so he did and it worked and he made contacs
