In the past, while living in an apartment, we tuned the drainpipe on the building and used it with our ham rigs. It worked pretty well. We were in Washington state and we got contacts in Russia and Germany.
i do live in an apartment and the balcony has large fire escape stairs that are 20 meters tall, i could easily connect it to the stairs without being seen from above because i'm in the first floor and the angle prevents directly seeing into my balcony. though i'm not sure if it´s electrically safe,
Dono how pertinent it is here, But my father connected his am radio to the copper piping in one of his old places to get a better signal. Could you do something similar for ham radio? Be completely stealth?
When I was taking the class for my Ham license, the teacher/president of the local club told us that from his homebrew antenna, on some day in the early 2000's when the weather and sun spots were perfect, he was able to reach New Zealand on 5W... from Pennsylvania.
as a bored kid growing up in the country friends and i would go out to the tracks where a road would cross them at night. We would get a mag light and run down the tracks like we were a train. We also would run a wire from one side of the track to the other to make the arms come down and the lights come up stopping cars as we would run down the tracks like idiots with our mag light yelling WHOOOOOO WHOOOOO like we were a train LOL :) Bored country kids ;)
That is so cool - LOL - Reminds me of the scene in the movie War Games, when the character shorts the contact in the pay phone handset, to make a call. More related to this, professional truck driver knows, if stalled upon the track, to get a pryer and break the small cable wire bonding the track, to immediately alert the system of a problem
Buried radials with a flag pole in the middle supported by a sturdy old whiskey bottle made an excellent antenna for global communication for 35 years at my dads house.
if those radials are tuned like the driving element above it will only allow the wave to resonate at the tuned freq. you can play with capacitance a bit but that was something i found worked well a tuned ground field or a tank circuit of sorts. when you try to generate a wave at any other wavelength it wont get out and you cant receive off band either. i think this is why boats in the sea are the best place to transmit outside of a ground field radiating from your tower. the height of the tower is also critical inside the size of the wave. ie 10 metre the best location would be exactly 10 m between the radials and driving elements. the lower bands would need to be higher off the ground or use a a half quarter wave tuned driver .
I remember being a kid in the 6th grade we had a teacher that would take the notes we would pass around in class and read them out loud. One day I got the idea to learn Morris Code and I copied it down and made keys for my friends and we wrote our notes in code just dashes and dots on paper and it drove that teacher nuts and we laughed about it.
I remember those days. We also started in 6th (or _maybe_ 5th) grade and used simple encryption (we started with single character subsitution and gradually learned more sophisticated methods).
The meshtastic thing is extremely interesting. I just went down a 4 hour rabbit hole on that. Looking into building a solar powered meshtastic repeater network.
Careful with lithium batteries and cold temperatures. Ultracapacitors work in hard temps better, but they don't store as much power. You'd also have to tweak the code for the MeshNode so that it doesn't shutoff and stay off when the voltage goes too low - you want it to turn itself back on as soon as enough power is available to do so.
@@Real_Tim_S Adding a solar panel as energy harvester, ultracapacitor bank for energy storage and a microcontroller for watchdog timer. Very solid that way.
I believe the Cuban people have become the masters of covert antenna building. Theirs, of course, are mainly for reception. Among my favorite favorite hacks are the use of CocaCola bottles for insulators (their shape lends itself to wires being attached) and I once saw a bicycle wheel being used as an antenna on a Canadian cod fishing trawler.
I'm a sucker for their homebrew power tools and appliances built around "that one Soviet washer motor that never dies even when the tub has rusted away" I hear their price per gig at the nationwide bodega sneakernet has come down to a few cents.
Well done. Low power, spread spectrum, novel encryption using digital one-time pads, burst comms are hard to detect, hard to track, hard to jam, and very secure. 👍
The fun thing with the simple Baofeng repeater is that with the addition of some Raspberry PI you have a networked IP repeater. Basically the two PIs act as a very long cable streaming the interconnect over the internet. You will encounter some sub-second delays in most cases, but you can then setup many-to-many repeater networks covering any reasonable distance. (I've setup a test system playing around that relayed Boston suburban transmissions back and forth to Seattle and San Antonio without a problem). The ~150-250ms total delay didn't make to much of a difference in well disciplined radio use.
For just receiving, I discovered while living in the back of my truck while traveling that I could connect the broken stub of an old handheld SW radio (using an alligator-clipped test lead) to the inside of my windowless aluminum canopy at night, turning the entire canopy into a really good antenna with world-wide reception.
If I may say, without being a know it all. On every USN ship I was on from 1989-1997 and again from 2002 to 2007 we always used sound powered phones, both for watch to watch communications underway and station to station. I dont think they ever stopped using them, it was just noted in lessons learned as a organic/attached C4I asset for said event. In every Damage Control Scenario, and Basic Damage Control PQS, which every sailor must qualify in, within 3 months after arriving at a new command, you must also qualify in sound powered phones and associated damage control symbology.
I was in the Navy from 1974 to 1979 and was an internal communications electrician and one of my duties was maintaining sound power telephone systems. I know at that time they were considered a critical system and was still very much in use I can't speak to periods after that. I know I did some research on the topic of number years ago and sound power phones are generally relegated to Very specific military and industrial applications. They're not a product you can walk into the local electronics or electrical supply house and acquire easily and they are awfully expensive. A better option would be to keep an eye out in various surplus catalogs and suppliers for military field telephones which are generally powered off a couple of d cells. They also provide for signaling from one phone to another or between multiple phones. Soundpower phones straight from the manufacturer have no call signaling capability which must be added as an extra set of components. The sound power phone systems we had required a completely segregated signaling system which employed a specially modified receiver called a growler, a hand operated generator and a selector switch to select the particular station you were trying to signal and communicate with. One of the problems with both sound power and field telephone type systems is that you need to acquire wire. That may seem a simple topic however several miles of single pair field telephone wire can be difficult and expensive to acquire. You can often find thousand foot and random lengths. Creating waterproof splices can also be difficult without the proper materials and tools. Other types of one pair wire can be utilized but most are not durable enough be used in what is essentially a hostile environment, that is through woods grasslands Rocky areas etc. I hope this helps.
@@chrissnyder2091 The splices are these days very easy to do waterproof. These days in submarines are used heat shrinkable solder sleeves. Very easy to use, just like a normal heat shrink but it will same time solder the wires and make waterproof enclosure from both ends with glue. I was watching a ex submariner presentation about old splicing methods, how difficult it was by all the methods to get it done right, and then he said that those ain't anymore required for everything as submarines started to use as well same sleeves from aviation. Of course critical connections are still done via best possible method. The market has flooded with civilian use heat shrink sleeves now, I wouldn't take those for submarine but for any other purpose they should be totally fine, especially for civilian use.
@@paristo My comment was not so much regarding splicing and I am aware of various heat shrink products it was more towards the twisted pairwire to be used I know the old-style military field phone wire was three steel strands and four copper strands and was extremely durable it's not something you can generally buy through regular sources although it's often available to the military surplus market.
Fun fact: On 9-11 I was a soldier overseas in Germany. Watched the 2nd plane smash into the towers and our brigade commander instantly put the entire installation on lockdown. We ran steel wire commo lines to every BN HQs from the switchboard in BDE HQ and used those as backup. So yes, the old-school porkchop "tanker phones" that are part of the inventory on every main battle tank in DoD are still being used when needed.
A couple of other ideas - using electric wire fencing to make an NVIS antenna on the HF bands. Unremarkable in rural areas. For VHF/UHF, take an unused pizza-box sized satellite TV antenna and cut slots into the dish to make a "slot antenna". Cover the slots from behind with gray spray painted cardboard and the mods could be invisible.
Some fun facts: - In the USA, an HOA *can not* prevent you from putting up an antenna for HAM radio. You can slap a 199' tower in your front yard and they can't do a thing about it. - Aluminum gutters can make a quite respectable antenna for HF operations if you have a good tuner (and you *need* an antenna tuner). With a good amp and tuner, significant DX ops are achievable. - If you have a non-conductive roof (i.e. not metal or solar panels) then you can string an antenna in your attic or crawlspace. - Don't forget about satellite repeaters on the HAM bands. Modern software tools and antenna trackers make satellite ops somewhat consistent, and it's possible with nothing more than a handheld antenna and a baofeng.
Not sure why you think that, seeing as you are entering into a legal contract with the HOA to abide by their regulations. They use courts and law enforcement to legally enforce these contracts.
@@cmerton I guess you go by Karen at the HOA meetings. See 47 C.F.R. §97.15, then go try to find some meaning to your life at the bottom of a bottle of wine now that you know your position on the HOA board doesn't give you ultimate power over your neighbors.
It’s my understanding that ADSBXchange ignores all requests to block aircraft. As far as military aircraft spotting with ADSB goes, fighters will pretty much never have ADSB, bombers and attack helos will sometimes show up, and transports and trainers are pretty much always have them. This isn’t a matter of their hex ID being blocked, but of the aircraft not being equipped with a 1090MHz transceiver in the first place. I can’t say what logic goes into which are equipped and which aren’t, but that is the pattern I see across the US. It is also important to note that the military is not subject to FAA regs about keeping ADSB on inside of US airspace (like civilians are). They are probably turned on during flights through civil airspace to mitigate collision risk, but I am positive that under certain FPCON conditions that all aircraft will simply turn ADSB off.
Yes but i think it's about monitoring. If you regularly check and monitor aircraft, then one day a military transport plane isn't broadcasting when you know it usually does, then you know something is up.
You can make slot antennas with old satellite dishes for any frequency above 130 mHz. The problem with using a repeater is that people get complacent and lose trak of time so if someone detects the location of the repeater they just have to listen for a while and get the input frequency then they can just start locating the individual stations who are using it while the repeater is in use.
I suggest what I am doing gentlemen. Pick one communication system that interests you and go down the rabbit hole. There is tons of information out there
Ill add an important device being a nanoVNA, incredibly important. Battery powered device that will help you to build a low loss antenna. SWR or standing wave ratio is RF that is reflected back into the transceiver. A high SWR will result in a reduction in power output to the radiating element of the antenna. If you are into HF mix31 torroids are also a good thing to keep in stock. These torroids are great at reducing RF noise and even common mode noise on your antenna feedline.
One thing we got trained for on the HF 150 radio was a connector that allowed the connection to a chain link fence. It surprisingly is a good antenna for long reaching comms
That is coming soon, working on it right now. It's a broader topic though, because everyone's needs are different. Just takes a bit longer to make the vid
As a ham I know about gain from antennas. Some give 3db or more of gain. But then if you have to use feed line depending on the coax you might loose 1db of gain per hundred feet or so. Then you have to evaluate you average height above terrain or AHAT. The higher you get the better you avoid obstacles that would block VHF.
For radio antennas, people can also use directional antennas to significantly narrow the directions from which the radio signal can be picked up. That way, a device can send signal to a repeater which is further from it than other listeners, and still have the listeners not hear the sender but hear the repeater, unless the listeners are in the cone of emission of the sender. Although laser is used, a phone camera and a small or tiny telescope (which can be very cheap or home-made) can transmit data without lasers, making it more difficult to be intercepted without knowing where specifically to look like. A few lights, which can be camouflaged as an internet router or broken screen of a device still powered on, can be used to send a message, and small electronic devices can decode the message. And the emitters and observers can be split to be located in the most camouflaged locations. Also people underestimate the power of using even if not satellites, just hot-air balloons or kites, to effectively get a device high up in the air. It could be used as a repeater, it could be used as a better antenna, it could even be used with medieval levels of technology (mirrors and/or lenses) to get an aerial image of other areas, or it can have cameras which to be used from the air. And an autonomous radar+lidar airplane+parachute could very well fly above an area, send or receive a message, then move to a different location. With some ingenuity, a solar-powered or wind-powered autonomous tiny plane/blimp/drone system could be used to periodically send and/or receive messages. Even those use-cases are useless in most situations, there are edge-case situations in which they would be very useful. Imagine looking at an enemy base using a phone, a telescope, a mirror on a tower or inside a house, and a series of camouflaged plastic lenses, to see from home what is going on at your job on the other side of the town spanning tens of km or tens of miles.
Atak used with the ttgo tbeam meshtastic units and a plugin called atak forwarder works beyond LOS with a simple tbeam at higher elevation or just simply between and some decent antennas
Your Repeater setup in the picture is flawned ! Transmitting on VHF (2M) will cause the 3rth Harmonic to jamm the HHF (70cm) receiver. You should do it just the other way around... Transmit on UHF and receive on VHF. Also note that suggested frequencies both are VHF 2M Which won't work Cause the TX will jamm the RX. Finaly if you'd build a repeater setup, at least respect the bandplan such novice users can use their default setup and other users are not jammed.
Great point about one way comms at 38 min. In OIF 1 I sent a one way message to a PSG with a rendezvous point based on his pistol serial number. Eg digit one up three digit two down four
One doesn't need 2 separate handhelds to create a repeater. There are a number of Dual-band (or multi-band) radios that have the ability to perform cross-band repeating (e.g. 2m to/from 70cm) within the single handheld radio. Single radio repeater functionality has been around at least 40 years or so. I'm pretty sure I remember seeing Bao-Feng also has at least one handheld model offering this functionality.
Problem is duty cycle. Using an HT for this is barely cutting it unless low duty cycle you would want a mobile unit. The reason you would want two units is for space diversity and to do something without cross banding, of course you would need some sort of cavity tuning system to prevent full duplex signals from coming back into the input especially if using common offsets like on 2M 600khz isn't much and a duplexer is needed. Also operators use two units dedicating one as a control link unit.based on preference and second unit as redundancy.
@@kerbalairforce8802 Have you seen the price of sturdy good quality ammo cans lately? A serious OUCH! However, I've also seen used cross-band repeater handheld and mobile units that were quite inexpensive and one of the nice things about them is they're a very fast no muss-no fuss to set up and take down solution: one need not mess with control wiring weather proofing, and adding solar charging isn't a major challenge. Like many things, the simplest solution can work for many even if not all situations or requirements.
You have to do the baofeng repeater with the two radios on different bands. Otherwise the antennas will interfere with each other. That's why repeaters that operate on one band are so expensive and rare. Also, you said nobody could direction find you with a repeater, but they can just look for the uplink frequency and find you no problem.
Was going to say the same thing regarding a portable repeater using same band radios. Tried it, did not work even with a duplexer and moderate horizontal antenna separation.
sorry, but I think he said to transmit to the repeater with a directional antenna; from what I know directional antennas are very difficult to find because you cannot intercept the signal from different angles making RDF useless. do you think it is correct or I have left something out.
@@gregh9237 its incorrect. Even the best directional antennas will have side and back lobes. They'll be reduced, but not eliminated. Equally you'll increase the range over which folk can find you in the direction of the repeater, your signal does not just stop at the antenna of the repeater. So yeah, it's just incorrect to state it protects against direction finding. Additionally, if they do find the repeater or get between you and the repeater they can then find you much easier as you'll be blasting signal in their direction. If they get off axis at all from you the signal strength will drop considerably, better giving a bearing to your location.
I did a video on the range of GoTenna, in the woods, its about a quarter mile to half mile. I live in north Georgia, there were hills and such. But I still like the idea of having them prebuilt, app included.
Railroad tracks have current or signal running through them and isolators that interact with the train location which measure the impedance of the signal running from the track to the signal source and tell crossing guards when to lower/raise amongst other things. You can listen to the signal with a earbud and a wire wrapped around a coil.
If you want something to do with burst on the cheap, use a Digi device FLDigi (plugs into a phone or ipad 3.5mm audio jack to provide impendence matching) then an APP like PSK 31 and run the FLdigi into a Baofeng and send complete PSK31 burst transmissions to another point. I did this out of boredom with another ham buddy using a simplex point to point Yagi 8 element 2 M beam on both sides for something to do. Watch the Baofeng TOT and heat output issues.
That was the best information. I have ever received about communication. I have been building little small Antennas, collectors boosters things like that. To increase my cell phone radios strength I live I live in the woods closest tower to me is Approximately 15 miles. I've had to turn 5G off. But I have 4 bars of 4G right now. I have built several Yagi antennas. I got one right. Thank you It may take some time but I intend on watching all your videos.
Just so you know railroad tracks are electric and are connected to each other The expansion gap is still connected to the other track because they are all bolted together Using hydro pole grounding wire works plus if you're near a power station the power poles are metal
Run coaxial underground to close telephone pole. Find cable support with turnbukle mounted in ground. The pole support cable works if you are high groung especially.
Modern track with signals has copper leads connecting each piece, each rail is half a circuit and the train wheels complete that circuit and show up on a screen at the dispatcher's office.
It's not only antennas the Lora protocol is fhss and if you have a gps you can have a time synced key so the radio not only knows what frequencies to hop on it also uses the ones with the least amount of noise
Not to be nitpicky but in your repeater example you show both input and output on the same band. This works on a full scale repeater with “cans” (mechanical band/notch-pass filters). It doesn’t work very well at all using two radios linked like this if they are next to each other. They will more often than not interfere with each other. Ideally you want to set up a cross-band repeater. One radio is listening on say VHF and one on UHF. This works well with some dual VFO mobile radios that can do it internally to the radio allowing you to turn your car into a moving repeater. Of course if you have a crossband repeater you need a dual band radio capable of being programmed to work with your repeater. An advantage of the crossband setup is also that the input and outputs are far apart and a bit less likely that someone can cause you interference, at least not as easily, since they may spend time trying to find the input frequency on the same band when it’s not even close! A trick I’ve used in the past when I want to operate with a portable that can’t reach my local ham repeater is to set up my crossband in the car with one VFO on the repeater input/output and the second VFO simplex to my portable. That can also be used to link repeaters on different bands with a station in the middle.
modern railroads are welded to be perfectly uniform (or as close to as possible) by stretching them out while cold first, so that when they expand, they dont have cracking problems or severe warping problems, and because they were already set up as cold as possible, they wont pull apart without significant wear prior
with more or less conventional radios, some mention of digital modes would be good. Consider various non speech systems, such as Hellschreiber, RTTY or various PSK variants. Some things are almost indistinguishable from noise unless you know what you are looking for and could be used on plain vanilla CB, UHF CB (via a repeater) or pretty much any radio system, just a matter of feeding it with audio from a computer with the right software and the same stuff at the other end. Plenty of free PC apps that handle a number of these systems.
To make a repeater, you'd have to use VHF on one side and UHF on the other. VHF to VHF would desensitize the receive so much that you'd never hear a thing. Real repeaters use tuned notch circuits to isolate the signal on the input AND output.
Still needs a lot of repeaters to cover distance. Also terrain can limit the freq more. I feel that mesh networks still need a lot more innovation. Definitely great on a local level for comms.
Tap code and Morse are the same thing I believe. It’s just presented differently. I haven’t heard of tap code before, but the pic you posted during the video was standard Morse.
LOT of focus on 'antenna camouflage' in various environments...without a lot of focus on frequency. Understand, that the standard AN/PRC-117F works across ALL FREQUENCIES between 30Mhz and 550Mhz (that's from 10-meter, across all FRS/GMRS frequencies, and more)! So, no matter 'how covert' your antenna is, if you aren't scrambled, a 'standard field radio' can eavesdrop on your conversation easily...and scrambling isn't cheap. AND, fresh out of DARPA research is the Rydberg Quantum RF Field Probe, they expect to be an 'all frequency' scanner for use by the military to seek out ALL RF use from FM to Microwave...(no word on where, exactly, they are in terms of completion on this project)
I love 117F if you know what you’re doing it’s easy to use and has way more functionality than the AN/PRC 1523 since the 117F can use VHF/UHF and if I recall it can also be used for HF coms
@@hussamgunter7381 Lower end is 30MHz to 60MHz that it can speak to an HF radio such as the AN/PRC 150. That may be what you're thinking. The newer 117G is even more wideband and is more of a networking radio kinda like how they are using the LoRa here. They've got an upper limit somewhere around 2.2GHz, although 250-512MHz is used for SATCOM. I've yet to use the upper band antenna jack on one because we use an HCLOS panel antenna for site-to-site networking.
@@danielvia8705 thanks man, I was thinking of the 117g but for some reason 117f was on my mind. I’ve used the 117g for satcom but not for HF yet. It’s a shame a lot of my guys don’t know how to use it, I’ve tried to get them trained on it but requesting satélite airtime is a process
I am no expert, but if someone has SDR, and comes in the vicinity of your repeater, wouldn't they see that you are simultaneously broadcasting from a different frequency (because the spectral view will show both transmissions)?
If you can find the repeater, you can find the input frequency and listen to the input frequency for continued searching for the rf source transmitted to the repeater
0:25 Even if the pins on the Kenwood connector used on baofengs matched anormal 2.5mm to 3.5mm audio calbe (which it doesnt) the audio level of the headphone pins in the 3.5mm jack on one radio is VERY much to powerful for the microphone pins on the 2.5mm jack on the other radio.
Heard it's possible as well but not sure of connection...would like to use w/Meshtastic. Possible/easier hookup may be near ground connected to vertical downspout that then connects to horizontal gutter.
20:05 actually, virtually every receiving radio emits radiation! It is extremely low level but can be tracked and located. An operator with appropriate equipment can determine exactly what “you’re” listening to as well. Radios have a local oscillator that mixes with the incoming RF signal and this difference frequency is what the rest of your radio process’s to extract the information (voice/data). It is this local oscillator that is transmitted via the antenna and/or circuits within the radio. Most people would be astonished by what information a seasoned electronic warfare operator can recover just my “listening”.
Your diagram is incorrect for repeating, one radio is UHF the other is VHF but the frequencies are both VHF. To do something like that you'd need a (very large) set of cavities. The reason you can do it cross band is the spacing lets the filtering in the radios work properly instead of over running the front end of the radios. If you guys are playing with the soldering iron something neat for you is the DRA818U or DRA818V RF modules. A full 1W transceiver in what is roughly a 2X1.5X.25" package. They're about $15-20 each. You'll have to add a micro processor, antenna, I/O and a battery. I was thinking about building a cross band repeater with some form of a weather balloon. Also I have as of yet to find a radio that doesn't suck to program by hand.
