Check it out here: https://www.4sqrp.com/T41main.php
(hint: you know it's a group of hams as soon as you see the colored fonts and grey background)
I assume that the v4 does as well. The earlier versions apparently also have this mode but it requires opening the devices up and a bit of soldering here and there.
The amateur radio community is very aware of the problems and several initiatives have been launched to quantify the effects. One of them is the DARC's ENAMS, which is described in detail here:
https://web.tapr.org/meetings/DCC_2020/DK5HH/F_ENAMS-DCC-DK5...
That can be effective but it's really only useful for cancelling out one noise source. I once used a similar device when there was something bad happening on a power pole down the street. It's no use if you have general noise from multiple directions.
The noise here is really bad due to my area and the construction of the building I live in. Much creativity is required to get QSOs from here.
Side note: if you read Hacker News, enjoy tinkering with electronics, and want to meet/talk to more people like you, I recommend becoming a Ham. The Technician and General exams from the FCC are relatively easy if you have any technical background and it's a great outlet for experimenting.
Next time I guess.
But I am very curious. Did you use a balun or antenna tuner?
I am however, for whatever reason, adverse to the social, or seemingly kinda social, aspect of the proctored exams.
Am I just making a mountain out of a molehill?
Also, you can take the tests online as well, you usually just have to have a camera setup so they can see you aren't cheating: https://hamradioprep.com/ham-radio-license-test-online/
Let's say "radio 1.0" is as it existed since radio was invented: convert raw analog or digital packets into a signal of a given wavelength as assigned by the FCC for the "type" i.e. nautical, hobby, aero, etc. Roughly associated with physical distance.
It's obvious we have the technology at this point where multiple streams of information can be reconstructed from one wire/pipe. My cable internet is mixed with thousands of other users and yet the cable internet system delivers me just my data.
Why is the airwaves not just another physical medium (metal wire, fiber optic, air)?
If I want to build an amateur transmitter to airstream my Twitch to my friend in Brazil, the FCC would say no, because
1. Can't clutter up the airwaves (the FCC manages the wavelengths) 2. For "safety" (government wants to monitor the stream)
In "radio 2.0" I can build my hobby hardware to whatever transmit power I want and use whatever wavelength I want because air is just another medium for the same signal. My question is roughly, why cant the organizing principles of my router, isp cable internet system, etc apply to over the air transmission?
Is it a physics limitation? Or a "we always did it this way therefore you can't have it" (FCC, etc)
Let's say I hypothetically have a high power handheld transmitter in my pocket powered by modern batteries, the FCC doesn't exist, and the power is the best that the modern batteries can provide, with the only tradeoffs being weight of the transmitter and duration of batteries, i.e. physics based tradeoffs.
Don't we have the technology to mix thousands of such handheld transmitters so that everyone can carry one, broadcast their own stream, and intermix the streams, and deconstruct the stream back to my own data?
Your hypothetical high powered handheld transmitter (e.g. you cellphone?) is limited by the amount of power from your batteries and other factors.
EDIT: The bandwidth of radio waves is also limited and there's noise which limits the total amount of data you can broadcast.
On point 3, we have made huge strides in miniaturization of electrical components since the dawn of radio; we have also made huge strides in battery technology.
That would suggest it's physically possible to build better devices, so maybe the limiting factor is more #2 nowadays, the ability to innovate is capped not by physics but by regulation.
Sure, things like LoRa exist, but are not widely useful.
If iPhones were a little more brick-like, maybe we wouldn't need to dump money into ISPs pockets; we could just have a standard communication language to bounce packets around. Then we don't need to pay cell phone bills, just buy new batteries.
I tend to agree that likely regulation is part of this but maybe a counter example is people opening their WiFi networks, which isn't regulated against, but people generally don't do. OTOH we could have regulation forcing all WiFi networks to be open? With some mechanism of paying people for bandwidth usage? But who would drive something like that? I think that's not different than me going through your phone on the way to the next hop? You will need to give me some battery life, and some of your bandwidth, so what do you get in return?
https://en.wikipedia.org/wiki/IEEE_802.11s
https://en.wikipedia.org/wiki/Wireless_mesh_network
The limitation is probably Metcalf's Law. It's difficult to mesh enough users to get the value of the network to match that of the cellular network, so the cellular network wins.
The trade-off for the long wavelengths is better permeability of the signal, which is why the author of the article is able to transmit so far on seven watts, but your Wi-Fi (high frequency and very short wavelength) has trouble getting through walls.
It just implies packet switching instead of circuit switching or message switching, and can be done at any frequency.
APRS is packet; anything that hears a position report can decode the data and decide what to do with it, as a unit. This is versus circuit switching or message switching-circuit switching being a dedicated channel (e.g. a phone call, regardless of what the underlying protocol is, since I know we can do things like VoLTE where the underlying network packetizes and multiplexes traffic) and message switching being like email-routed all together somewhere, perhaps via multiple hops.
Basically just want a glorified walkie talkie with a bit more range (a few miles through woods and across hills of possible).
I just got my GMRS license and some cheap 5W handhelds to experiment with, but I'm not sure if that is the best option.
We might also have the option of setting up a "base station" at the trailhead (our cars or someone relaxing at a picnic table) to act as a higher powered repeater if that would help.
How much of it is frequency (radio type), wattage, line of sight, operator skill. etc.?
I think in some places you can set up a repeater for GMRS? You'd have to check up with the local regulations.
Of course, you could get everyone (or a few designated people) ham licensed. In many areas, operators are allowed to let other people use their radios under their supervision, so you might not need to even get every single person licensed.
Frequency plays a very big role, and the rest "depend".
There are some frequencies that'd just simply be impossible to use for communication that close (in the grand scheme of things) and others that would struggle to penetrate the trees.
Without knowing the area, I'd guess that 2 or 6 meters would be your best bet. (Probably 2m)
Your next challenge would be getting good antennas. The antenna matters a lot (even more than power output. (See me hitting Australia with 7w))
I'm always available for questions via email. You'll find it in my website.
> Without knowing the area, I'd guess that 2 or 6 meters would be your best bet. (Probably 2m)
What is this in reference to? Is that a measure of wavelength (e.g. 2-6m ~= VHF?) or did I misunderstand? I thought for longer-range comms, you would want to utilize not just repeaters but things like ionosphere reflections and HF. Are you saying that's actually not the best thing to use for wooded areas a few miles apart?
I appreciate the info :) If I really get into this as a hobby, I'd love to hit you up via email. Please give me a few weeks to test the waters first.
A 50kb/s bit rate is fast enough for texting, but I guess it'd take some specialized voice protocols to do a walkie-talkie over that.
Regardless, thank you for sharing.
But generally yes, latency is too high and bandwidth is too low for synchronous voice. The upside is that real-world performance often exceeds the range of analog UHF even at significantly lower frequencies, e.g. GMRS.
As a non-radio enthusiast, I was following along until this sentence.
14080Kc ( = 14080 KHz = 14.08 MHz), 10136 (=10.136 MHz) and 7074 (=7.074 MHz) are the frequencies of the radio channels being used.
The ionosphere (which is partly powered by the sun) tends to dissipate at night and not reflect higher frequencies as well. Thus one tends to use lower frequencies during the evening/night and higher frequencies during the day.
As an aside, an ionosonde is a radar which can measure and display the reflectivity of the ionosphere in real-time as function of things like height/range, radio frequency and direction. Not many people get to play with them, but they are a great tool to learn how the ionosphere works. You can sit in front of the display and watch in real-time as the ionosphere's response changes and it's height increases as night approaches and see how it varies from day to day. Beats reading about it in a text book and it's fascinating to watch.
Here's a link to an online ionosonde, displaying ionograms in real-time, updated every 5 minutes:
The other comment under yours does a great job explaining things too.
As an additional note KC (Kilo Cycles) is the old way of writing Kilohertz. I just happen to prefer writing Kc for some reason even though I know it's no longer "correct"
* https://en.wikipedia.org/wiki/Random_wire_antenna
There are also commercially available products that are fairly portable and probably give you a better SWR; e.g.:
* https://www.youtube.com/results?search_query=Buddipole
From one of the photos, seems like the author is using an Elecraft KX-2, which is really a clever bit of kit that packs a big bunch in small package:
* https://elecraft.com/products/kx2-ssb-cw-data-80-10-m-transc...
On this particular trip, I had my antenna at a perfect 1:1 the whole time.
The receiver is very sensitive and the filter can be adjusted to clamp down on one signal. I do CW most of the time so I can setup and make contacts in a lot of noisy, challenging places, from Grants Tomb in NYC to a little POTA site just north of KC airport with power distribution lines high overhead, I've been able to work coast to coast with either an end-fed halfwave or a Chelegance MC750 vertical. (Far easier and less bulky than my Buddipole or Buddistick). I also have an end-fed random wire for use with my KX2. I took it to Old Town San Diego and was able to band-hop while a friend was on 20m at the same picnic table. With the random wire I was still able to pull in Italy on 5W!
I'm headed for Madison, WI tomorrow and will be playing radio in the evenings weather (and solar storm) dependent.