Comments on: WSPRing across the Atlantic

By: Janne

Janne — Fri, 15 May 2009 15:16:50 +0000

Very cool experiment. The furure in in low-energy communication, and if you can send a message across the world just using 20 mW, then compare this to send a mail over the internet that uses many-many millions of Watt in power for all hardware needed.

By: Oren Beck

Oren Beck — Sun, 10 May 2009 16:10:28 +0000

There’s a phrase “SHTF” denoting something hitting the fan. Among the possibles are several that would not only have no “utilities” -but severe havoc wreaked on the whole RF spectrum. And from that, any established robust paths become very good things.

The same tech that holds a signal at 20 milliwatt across oceans might do likewise across planetary or farther distances. Or in the true hacker thought process- 20 mw across oceans or 1 mw across a city- or how low power can we go for across the room?

By: Hitek146

Hitek146 — Sat, 09 May 2009 22:53:28 +0000

^^^lol… there are no different “senses” to the word bandwidth. bandwidth!=speed, although wider bandwidths are better capable of easily transmitting larger volumes of information…

By: Pouncer

Pouncer — Sat, 09 May 2009 13:29:28 +0000

While the unit is impressive, and of course it’s equally impressive that it crossed the Atlantic on such low power, I’d really like to see the antenna used.

By: pakbehl

pakbehl — Sat, 09 May 2009 05:34:27 +0000

the magic isnt lost in having it wired to the web, it’s distilled

By: David

David — Sat, 09 May 2009 05:05:13 +0000

Congratulations to Bill N2CQR for achieving this. Especially when the transmit antenna is, “just an end-fed wire among the buildings of central Rome”.

It should be noted that the receiving end requires a powerful (and power consuming) PC running some pretty sophisticated Digital Signal Processing (DSP) software.

The transmission bandwidth is very small and therefore the information rate is very low. The signal is something like 25-30 dB BELOW the noise.

By: silic0re

silic0re — Fri, 08 May 2009 22:54:42 +0000

bill: oooh, bandwidth in the signal processing, ‘narrow frequency range’ sense of the word, as opposed to the ‘information throughput’ sense. thanks for disambiguating that! :)

By: Bill

Bill — Fri, 08 May 2009 19:46:07 +0000

silicOre: You trade speed for bandwidth in this sense: To receive REALLY weak signals (like my 20 milliwatts after crossing the Atlantic!), the only way to do this is to cut back drastically on the noise. You do this with VERY narrow filters. Like .3 Hz narrow. But Shannon tells us that as we reduce the bandwidth, we have to slow down the rate of info transfer. So as we narrow the filters, we have to slow down the code. In QRSS, the Morse code. So to use the narrow bandwidth, you have to trade in lots of speed.
Whhat: My rig is on 10140200 Hz.

By: emilio

emilio — Fri, 08 May 2009 19:21:15 +0000

sol, actually ham radio is one of the most un-regulated pieces of government licensing, at least in the united states. the FCC monitors a very tiny slice of amateur radio activity, and the rest is “self-regulation” where hams keep an eye on themselves and each other.

in fact, the FCC just says “these are amateur bands” and then amateur radio community agrees upon usage plans, without significant further input from the government. but, legally, you can do pretty much whatever you want in amateur bands if you abide by basic regulations on power and identification (you cannot, for example, intentionally encrypt or obfuscate communicaton).

but the real discussion is about regulation. hacking != illegal, hacking == innovation. radio spectrum regulation is a *good* thing, it keeps this very, very wireless society on the air; without at least basic regulation radio would be useless. the alternative is that private business regulates the airwaves, because they would have the money to crush any new signals. what, you think companies would play nicely without the government? *that’s* antithetical to the hacker spirit.

and if you really wanna stick to your guns and somehow be “better” than everyone else because you’re “independent” or something (have fun in your cave in the hills), then low frequency is the place to be: it’s unlicensed because it’s not used for much.

By: sol

sol — Fri, 08 May 2009 17:29:48 +0000

Isn’t ham radio’s constant focus on conforming to government licensing requirements antithetical to the hacking spirit, regardless of the homebrew history?

By: silic0re

silic0re — Fri, 08 May 2009 16:16:58 +0000

just a quick thought about an edit, but in the sentence “WSPR (Weak Signal Propagation Reporter) trades speed for bandwidth and allows for the reception of signals that are far below the level of radio noise.”, the phrase “trades speed for bandwidth” doesn’t make very much sense, because speed and bandwidth are essentially synonyms in the “throughput” sense. I think the writer is trying to say ‘trades speed for reliability/robustness/the ability to traverse vast distances on very low power’.

still, this is very intersting stuff!

By: Wwhat

Wwhat — Fri, 08 May 2009 16:11:49 +0000

Took a long time before I finally got what frequency is used, seems damn basic information to me though, and in fact saying how many milliwatt you used is pointless without knowing what frequency is used, I mean radio’s upper atmosphere reflection needed for long distance is highly dependant on the frequency

(It seems to be used around 10.14MHz and 7.04MHz and rarely 14.09MHz I gather from the reports)

Also it might be nice if someone created a wikipedia entry for WSPR, someone who’s willing to put in all basic info including frequencies generally used ;\

By: Jason

Jason — Fri, 08 May 2009 13:34:42 +0000

Very cool, love the ham hacks. :)

73′s de Jason, VE2 RIF

By: Chris

Chris — Fri, 08 May 2009 12:52:35 +0000

@ Muri & M0GDU

Here in the states, licensing is split into 3 levels, with the tech test (lowest level, mostly giving VHF and higher frequencies) mostly focusing on the rules, and some limited technical.

I love the idea of having a working radio project as a requirement for higher levels, but I can’t see the FCC doing that. Our higher level licenses here do have more and more technical tests required. Here, the question pools are public, and you can take practice tests online from a number of sources.

By: Richard

Richard — Fri, 08 May 2009 09:09:53 +0000

@ muri – go do it, you’ll have a lot of fun learning the stuff you need to for you ham license, I know I did. :-)

although these days quite a lot of amateur radio relies on shop-bought ‘black boxes’ the original ‘if you want one, build one’ spirit is very much alive and well too.

I don’t know what the licensing protocols are where you live, but here in the uk you must build a project of sufficient complexity that works in order to pass the intermediate license testing – this is, imho, a very good thing as it ensure that at least basic diy and component-level fault-finding skills are there. the full license is much more theoretical and contains some heavy math, but all of it is useful… if I could have said the same about the math i learned in school I’d have been much more interested!

73 m0gdu