There was a time when you could do what you wanted in your yard and hams could build giant antenna farms. These days, there are usually laws or deed restrictions that stop that from happening. Even if you can build an antenna, you might want to quickly put up something temporary in an emergency.
[Eric’s] solution? Suspend a wire from a weather balloon filled with helium from the local WalMart. The 8 foot balloon took two containers (18 cubic feet) of gas before it would rise sufficiently. Once you have a floating balloon, the rest of the concept is simple: connect a wire (100 feet of 26 gauge), use a tuner to match the load to the transmitter, and you have instant antenna.
The Army used this same technique with the SCR-578 survival radio. Instead of helium, a chemical reaction produced hydrogen that lifted a balloon that would hoist a kite that kept the antenna aloft.
Usually, when we see balloons, they are going much higher. We’ve thought about lifting antenna wires temporarily with drones, but maybe you just need a potato.
If you are going to use a drone to trail your antenna why not add a SBC and SDR then down-link the data via WiFi so you can get your antenna up as high as you can legally go. i.e. Put the radio in the drone too.
The military has been doing this off and on but with blimps. Either putting the whole radio in the blimp downlinking via another RF method to the ground or just the RT portion with a cable down.
It makes a lot of sense to do it for them as the down-link is a tight beam and therefore their exact location cannot be easily located. You can take out the drone but never be sure where the owner is.
The tether kinda gives the location away
Only if you are on top of it. tethers are invisible from any real distance away. and the military used very thin ones so they were hard to see even when you were close.
You put a tether on your drones? You_Failed_Drones
I miss ham radio
I miss tolerant next door neighbors.
That too…but having a inverted v in Denver…hmmm…might be fun and the antenna described here…i miss ham radio
I miss trolls saying “not a hack!”
Wasn’t there a law passed that prohibits cities, HOAs, etc. from restricting the installation of outdoor TV antennas? While that wouldn’t work very well with HF, for the VHF/UHF amateur bands, it could be possible to install a dual purpose TV antenna that also happens to work for amateur radio.
Not HOA’s they protected the Gestapo HOA by putting a clause in that if you signed away your rights you dont get to have your rights.
Yup, don’t support the ARRL.
Uh,the ARRL is supporting the Amateur Radio Parity Act that’s before Congress right now, it will override a lot of HOA restrictions on antennas. Maybe try reading up on what the ARRL is doing instead of knee-jerk “don’t support the ARRL” BS.
Natural house gas works too. Not as much lift but a lot easier to get.
Methane would give better lift than this awful helium-air Walmart gas mixture, plus wouldn’t escape through the latex in approximately nine heartbeats like helium does.
Their $40 worth of diluted helium lifted 350g. For about ten cents.
Something funny there with the text editor and greater/less symbols… Repost:
Methane would give better lift than this awful helium-air Walmart gas mixture, plus wouldn’t escape through the latex in approximately nine heartbeats like helium does.
Their $40 worth of diluted helium lifted less than 300g. That 18 cubic feet should lift 600-700g if it were the real stuff. But if it were 100% helium then a Walmart customer huffing it would die. Adding half air keeps their customer base alive to buy more junk.
18 cubic feet of Methane will lift more than 350g. For about ten cents.
I understand that they payed way too much for that amount of “helium” but the tanks they got aren’t intended to be pure, or even a good lifting gas – it’s for filling party balloons.
Nah, they dilute it ’cause He is expensive and there’s a (real or manufactured) shortage of it. The dilution is because you don’t need pure He for balloons.
I believe the original military antenna used H, not He, and generated it from seawater, possibly mixed with something dry.
H is available cheap. It’s what they’re using now for weather balloons, I believe.
Diluting it also removes it from the controversial assisted-dying market and its associated bad press. Image is everything.
And it would be H2, not H.
Sticking a motorcycle battery vent tube into a garbage bag and overcharging the heck out of it makes a dandy little lifting balloon too, but makes one heck of a bang when it ignites, and can blow out your garage window (and make your ears ring for a few days). No, you don’t need to ask me how I know this.
Leaving this here because it’s relevant: http://hackaday.com/2016/07/11/the-dubious-claim-of-a-world-helium-shortage/
Re: the dilution being to thwart the assisted-dying market.
Sure hope nobody tells them about the nitrogen you can get from a welding supply store. Breathing that will kill you just as quickly.
(but your last words will be at a normal pitch…)
They cut their helium like street drug-pushers? Unbelievable.
LMAO!
Doesn’t using a balloon have a ‘static’ issue?
I just looked it up; watch out for lighting, sometimes it’s a sunny day…
You ‘Hamsters’ are awesome.
Yes, it does. We found this out at Field Day one year. There’s a voltage gradient in the atmosphere (voltage at the balloon end is higher than the voltage at ground level), so you will see a DC current trying to flow down the wire. Easily fixed, just use a coil to ground as part of your matching circuit. But beware when connecting or disconnecting, you don’t want to be between the end of the antenna wire and ground. Use a jumper to ground the antenna before unhooking it from the matching network.
Good point re the DC current. I was thinking of flying a kite antenna for a crystal radio and hadn’t considered that.
We’ve used that current deliberately here http://hackaday.com/2015/11/22/who-is-john-galt-finally-answered/
How much power/current could you get from this?
Enough to wake you up. My friend got a pretty good shock from it. The balloon acts as a charge collector, too…magnifies the effect.
So what happens, is that you get a charge buildup on the balloon. The longer you wait before discharging, the higher the voltage. Not much current, but a heck of a voltage kick, IIRC. If you constantly bleed off the charge, you’re fine. He just used a tapped coil with one end grounded as the last element in his matching network and was fine. I suspect he had a series cap on the radio side to keep any voltage spikes from blowing his rig’s final transistors.
Now, as to how much power you could get…it’s probably not a lot, though if you let the voltage get high and sipped currrent, you could charge a capacitor bank, then regulate it down with a DC/DC to something you could use. Might be a fun experiment, but make sure your caps can handle hundreds of volts.
Tried this once, with inconclusive results. Might not have had my long-wire long or high enough…
I’ve been toying with this concept for a while, I have some nice thin telephone grade wire I’ve considered doing this with. The problem I have is that I can’t justify wasting that much helium on such a temporary setup. It absolutely makes sense for emergency or in remote locations where it is impractical to build a proper antenna. At my house? Not so much.
Also **** neighbors that get pissy over the things you do in your own yard. If it’s structurally sound and posses no risk to them or their property then they can stuff their complaints. “Ooohhh it’s blocking my perfect view of the trees on miles over there…” Screw that noise. Nobody owns a view, and not blocks a business from building next door becuase it will lower property value, level our antennas alone. I think a law should be passed that places radio under freedom of speech. Get your license to operate potentially dangerous equipment and your good to go.
As far as wire goes, a surplus electronics dealer called Greenweld used to advertise in all the electronics hobby mags in the UK, back in the day (1990s / 2000s). Dunno if they still do.
Anyway, for a pretty low price, they had reels, kilometres long, of guided missile wire. For wire-guided missiles of course. Ludicrously strong, very thin. That’d be great for something like this, better than telephone wire I think. The fact Greenweld had it, means that it’s available on the surplus market, or at least was, maybe they were scrapping some old missiles. Do they still make wire-guided ones? Might still be a few kilometres worth around somewhere to buy. One use they suggested for it was fishing line, not likely to break for any fish slower than the speed of sound.
Greenaum – They have a website but I couldn’t find your wire spool. You can try if you like:
http://www.greenweld.co.uk/cgi-bin/ss000001.pl?SS=wire&ACTION.x=7&ACTION.y=5&PR=-1&TB=A&SHOP=
The BGM-71 TOW is still in the US inventory.
jack324 – Supposedly you can make your own HYDROGEN with sodium hydroxide, water, and aluminum foil. The Sodium Hydroxide can be found in commercial oven cleaners like Mr. Muscle (SC Johnson Co). Potassium Hydroxide may work too. I’ve seen YouTube where the balloons once filled and tied off, take off for the cieling.I believe HYDROGEN has more lift than HELIUM. However, this is dangerous as hell!
Use a kite, helium free!
One way to extend your UHF radio range is to make a Quad-Perch (QP). A QP is a large flat wooden landing pad with a bulls-eye target on it for the quad-csam to see and maybe flashing LEDs. This is like the Amazon quadcopter package delivery idea. The QP would be mounted on top of a high building, tree, pole, mountain, etc. You’d take a SIMPLEX REPEATER (SR) and a simplex walkie-talkie aloft to the QP. You’d carefully land on it and cut your engines to save battery power.
The SR and the W-T is self-powered. It’s nothing more than a delayed audio store and forward device. Radio Shack used to sell them. You can build one with an Arduino, You’d need a very small W-T to reduce payload weight.You would be repeating your voice several seconds later on the same frequency.
Hopefully the wind wont blow your quad off the QP.
Vertical polarization though right?
“There was a time when you could do what you wanted in your yard…”
Welcome to Socialism Comrade. Your local Community Organizer will be watching you!
That’s Fascism not socialism. Pure socialism is about everyone giving a little to help those who need it. Fascism is the one where the government is in every aspect of your lives. And from every HOA I’ve seen they are Fascist orginizations.
Actually you can’t do WHATEVER you like in your own yard (i.e. walk around naked, use open toilet, erect outbuilding without town authorization, etc.) Take a lesson from CELL phone tower companies. They are erecting fake flag poles and pine trees with a vertically polarized antenna system in side. Citizens protest new cell phone towers as being unsightly and lowering their property values. This is how these commercial landowners replied: https://goo.gl/2Azqyg
Also since 911 DHS did ask people: “See something say something”. It’s not socialism to have common sense in a new world of bad guys. Also USPS (e.g., federal employees) is ordered to do it everyday. They are supposed to report high-strangeness to their route-supervisors when they see it. The supervisor calls DHS or FBI.
Also when you SIGN a HOA agreement you are basically screwed. You can’t out-trump a voluntarily signed contract. If you didn’t like a clause in your HOA agreement then cross it out and initial it.
FYI – A new concept no one has noticed yet… ever see an outbuilding on top of your favorite store or business? It’s a new concept called RADOME CONCEALMENT BUILDINGS (Google: ConcealFab Corporation). It was originally design for US Military to disguise critical radio systems in the field as an innocuous shed or outbuilding that is invisible to EMF by way of the special building materials. Cell phone companies have adopted it now and they are quietly popping up on roofs nationwide. You notice a strange shed on a commercial flat roof. Go to the side of the building and you see the tiny masonry bunker they erect to contain the electronics. The RF cable goes up the wall to the shed. The roof access door in the store is usually marked EMPLOYEES ONLY, ELECTRICAL CLOSET, or any thing to make you mind your own business.
RE: Flying Kites: I saw a small kite at the store that had a pocket for releasing confetti. It had a string-release mechanism. So yes if you had a windy day and no trees to foul up your kite then do it. However, don’t do it during an electrical storm like Ben Franklin did! :-)
In regards to antennas the military uses, the weather balloon antenna are rare. We still climb trees, poles, water towers, and cliffs to place highly directional antennas for our comm systems. Don’t stand in front of one, but feel free to cook your hotdog on a stick from a safe distance (at least with the sat uplink trucks).
I’ve seen USG use small airplanes (FBI and local ANG) as mobile repeaters, Also the US Border Patrol uses small blimps as relay systems.Local LEO’s (i.e. Staties) have RATs, which are mobile walkie-talkie to main radio repeater from his car. He can operate his longer-range car xcvr with a small w-t on his shoulder.The most clever (if not stupidly administered) was the PDA SPY ROCK method of store and forward repeating. It would have been a great way to distribute your message traffic to several different field assets if you didn’t try to fix the battery in the field right in front of watching state security personnel. (http://news.bbc.co.uk/2/hi/technology/4639782.stm)