If you're running a website with Apache, you can configure Apache to look at the HTTP_REFERER header and see where the web surfer was when they made the request for the image. If they weren't on your website, (or if they don't provide the header, an act to be widely discouraged), just re-direct them to your home page instead of serving the image.
I would think that other web servers could do the same thing, one way or another.
For most people, it costs money -- perhaps not a huge amount, but still, real money -- to put up a website and serve content to the world. The expectation, if not agreement, is that you'll look at the site's content on the site.
The webmaster's position is no more hostile than that of the deep miner: There are expectations, but no promises.
Google's search goes far beyond fair use, as far as I'm concerned.
Exactly. At 60+, there aren't even any open doors if you are skilled.
There's talk -- you can get interviews -- but you won't be hired.
Here's how corporations really see it:
Older workers screw up insurance plans, are assumed to expect higher salaries (or to be discontented even if they claim they'll take a lower one), they have more extended families, they get sick more often, they take more time off, they're more chatty/garrulous, they won't integrate well with "the kids", they pose higher slip and fall risks, it's more difficult/stressful for them to travel, their knowledge tends to be stale... and you probably look like crap in a miniskirt.
Ok. WTF. I've been seeing that phrase for years now, and I *still* can't quite figure it out.
Where can I get this free beer? Because apparently, for some reason, my area doesn't have a source. I've looked and looked, and beer, even really lousy beer, just isn't available for free. Not even if you make it at home... you still have to come up with the ingredients. And bottles.
Would someone take a moment to explain this strange turn of phrase to an old dude?
Congratulations, you've just handed all land over to whoever has the physical power to conquer it.
In the US, in most cases, your land can be taken by the courts for any number of reasons. It can be taken if the government wants to build a road, or, in many states, if a corporation has a plan for your land that will earn more taxes than you are presently coughing up for the same parcel, or parcel plus its neighbors. So while you might think of the government as "backing" your property ownership, there are also many situations where the government is adversarial in that regard.
You posit a world where disputes over the positions of garden fences would be resolved at gunpoint. Thankfully, most of the rest of humanity is smart and mature enough to see that this is ridiculous, and disregard you.
Well, the tradeoff for this apparent peace of mind, at least here in the USA, has been creating a situation where you can't defend your land from the remaining entities that want it. And, if your neighbor has enough money, that includes them, too, in any state that hasn't enacted specific types of laws controlling eminent domain, since SCOTUS took a pants-poopingly stupid position on the matter (in Kelo v. City of New London.)
Huh. I thought the livestock were the ones doing the grazing. Of course, if the cattlemen's heads are down there cropping grass, I probably wouldn't have noticed them, so there you go. Slashdot: Where you can learn something new!
We made it unlawful to sell other humans into slavery for moral, religious and social reasons
No, actually, we handed the government a monopoly on slavery and indentured servitude. The 13th amendment:
Neither slavery nor involuntary servitude, except as a punishment for crime whereof the party shall have been duly convicted, shall exist within the United States, or any place subject to their jurisdiction.
Considering the overwhelming nature of the web of law as it stands today... it's pretty easy to find yourself involuntarily making license plates, etc., for a corporation.
Related stat: At this point in time, about 3 million US citizens are jailed (about 1% of the population.) Furthermore, some prisons are moving to private ownership, so they essentially inherit the forced labor value of the prisoners.
Which is the opposite of the intent of US copyright (note this is not a US app/project), which is to, for a limited time (too long right now, but that's another discussion), secure the rights to the author so that eventually the work will promote progress. From the constitution:
To promote the Progress of Science and useful Arts, by securing for limited Times to Authors and Inventors the exclusive Right to their respective Writings and Discoveries;
In the US context, at least, this would work against such a thing. The way I see it, someone writes a book, eventually, that book should become part of the shared knowledge base, arts base, etc. I'm wary of a concept where a book is only available in part, where readers may never get the whole thing, and where e-readers... not exactly known for avoiding DRM and other such intellectual poison... contain the only (partial) copies.
A used book should be a treasure, something saved and valued and passed along. Electronic or not.
SDR performance advantages: ability to dig signal out of noise. Ability to remove noise. Ability to control the bandpass. Sharpness of filtering. Ability to see what's going on around the signal, and spot signals, in unbelievably low-signal or high noise conditions -- or both. Time division multiplex filters that pull out many carriers at one time and leave excellent audio behind. Ability to ID digital signals visually in just moments... every type of digital signal has a different spectral "signature", and so I know I'm looking at Olivia, or RTTY, or SSTV, or whatever. Ability to record, and play back, entire bands. High resolution realtime carrier analysis. Ability to remote the receiver head. Precision metering. Completely reconfigurable in seconds. Direct integration with all manner of analog signal processing (eg soundflower, Audio Hijack Pro, and just about every audio plugin you ever heard of.)
Ability to get right in there and code whatever feature you want.
I had a Yaesu FT-2000, with the DMU and speaker and all the goodies. My $500 SDR-IQ wiped that thing out. On the same antenna, it could pull signals out of the noise that simply were impossible to hear at all on the FT-2000. It eliminated noise the Yaesu couldn't do a thing about, not with DSP modes and not with the blanker. The bandpass control (shift, width) wasn't even remotely comparable to the ability to drag a razor edged upper or lower bound. I sold the FT-2000 and its accessories. It was pointless, just a ton of knobs and buttons that couldn't even come close to keeping up.
I also have an FT-980, an old school analog ham radio; also can't keep up, just hears noise, mostly.
Here, the FT-2000's (presumably) greater sensitivity was useless; the noise level was too high, and it couldn't get rid of it. The SDR-IQ, plus software, eliminates the noise, so I heard much more. Then, having heard it, I can isolate it better because of the bandpass.
It doesn't do you any good to have certain types of specs unless you have a pristine signal environment. And where can most of us find that? Unless... unless you have RF signal processing that's so good as to obviate the noise. And that's what sits on my desk.
The SDR-IQ is not a top of the line SDR; RFSPACE (and others) make much higher performance ones. Yet it just kills in operation. I'd like to try the higher end ones someday. But I know from using this that an analog radio just can't get there.
I have lots of other SW radios, receive-only, also. The FT-2000 was the best receiver, but I've been collecting them for years. None of them can touch the SDR-IQ.
And finally, all this at about the cost of the high-end microphone for the FT-2000, the MD-200.
I'm not really talking about "stick" type SDRs here. You need a decent front end, and you need stable, high resolution sampling to avoid various artifacts. But if you can meet that fairly low standard, it can be an eye-opener.
Also -- like any radio -- you need to know your way around the tools you have. Given that I wrote my own, it's fair to say that I'm an expert user. But I also spent a lot of time with that FT-2000, I can tell you, and it's limits were surpassed the very first day I put the SDR-IQ on the same antenna.
I can't help but notice that you weren't able to come up with an example of a better SDR for my application.
I can't help but notice that I didn't claim there was one.:) You do know what a "straw man" is, right?
"cuteSDR" doesn't seem relevant because I write all my own code to control the radio, demodulate (FSK/NFM) the signals, correct the parity-checked bits so the CRC matches, decode the content, etc. It's really irrelevant
CuteSDR is a great starter app that can be tweaked to work with anything. You didn't mention that you wrote your own code, just that you wanted "linux support", and inasmuch as that would mean, get ready, "software", I pointed you at the software that would support whatever hardware you wanted to run, which I had already assumed you had identified, because, get ready, you had said so. If, as you say, you write your own software, then "linux support" is pretty irrelevant, because you'll be doing the writing. I just figured you were looking for software because I'm unaware of any SDR with a "linux connector" or a "linux spectrum", ya dig? Consequently, I pointed you at something that had already done most of the difficult stuff. You're welcome, even if you're maybe kinda working a bit too hard at missing the point.
Public agencies trunked radio
I see. Something commercial, then, from the secrecy, etc. Good luck with the project.
Why you would imagine that a $20 dongle could arrive with an FM broadcast tap
"trap" -- typo, dunno if it was yours or mine, too lazy to look. A trap can be as simple as a coil and a cap, especially in this kind of setup. Small, too, at 100 MHz or so. Nothing expensive.
Are you having a bad day? My sympathies, if so. You seem to be grasping at the idea I'm your adversary. I'm not. I'm just some guy on the Interwebz.
You mean like VOR? Those are up in the low 100MHz, of course...
No. I'm talking about CW format beacons. They're all below 540 kHz. Very useful to see what LW prop is going on.
It's true those are all present, but "interesting" is in the ear of the listener. None of those qualify as "interesting" in my book.
Well, sure. That's the way everything is, isn't it? I'm answering you from my perspective, because you asked me.
Are there other military signals
Yes, tons of 'em. Not just out of the US, either. You can also see spectrum probes sliding across the various portions of HF; hear mystery "coded" signals (numbers stations), even see some weird stuff that's (thus far) eluded any explanation, like slow carriers that transit the 49 meter SW band, right through the commercial stations and a very sedate and extremely stable pace. No idea what that is. Just find it interesting.
Ok this [flares] is a little interesting, I'll give you this one.
LOL, thanks.
Ummmmm. Those little buggers [bats, insects] use radios?
All you do is for your "antenna", you hook up a tweeter or a supertweeter, and hang it out by your eaves, attic entrance, etc. Feed that to the SDR-IQ. All manner of hilarity ensues. Including the lady of the house going "what, bats? We have BATS?!?!?"
What is interesting or useful about this, especially given the GPS timebase being globally available?
Well, they're also typically frequency references. You can do a number of things with them. First, they tell you about propagation (because they're always on, so you know what's on bounce by what you can hear.) You can do some cool experiments like these. They give you deep sea weather reports, too. WWVH (Hawaii) and WWV (Colorado) give you an instant tip because one uses a womans voice, the other a mans. You can tell how prop is going by what you hear. There is also BCD coded time on there. And many nations have time signals, if you know where they are (and my software does.)
[CB] One person's interesting is another person's ridiculous, I suppose.
Well, yes, exactly. CB is bloody hilarious to listen to. At least to me. And it also, because it's so busy, serves as another type of prop indicator. Even if the ham bands are dead, for instance, you can tell they are open, just not in use, when the CB bands are open.
You mean 27MHz R/C? The servo signal seems particularly boring, unless you are operating the R/C device, in which case you can look at it.
What it tells me is that it's time to go outside and check the skies for our local air club, so I find it quite useful. Think of it as a "beacon for fun." I can also tell the guys if they're making a mess - too broad, etc. Listening is not everything; analysis and reaction is interesting as well.
I think 1090 MHz is more interesting than anything you mentioned. 121.5 is worthy of note. The 450s and 850s (public safety and government) are pretty interesting to most people. Other people enjoy trying to figure out SCADA traffic in the 400's.
Ok, great. More power to you.
My complaint with your Score-5 first post
Dude, seriously, don't blame ME for slashdot moderation. It's totally broken and I've said so for years, but in any case, I didn't mod the darned post myself so I don't see how I should accept any blame for it whatsoever. Seriously. The mods here are only on crack when they aren't on meth. It's something in the perl code. Nasty stuff. As for the first post, I saw the story (twitter
Don't use the original remotes for any complicated system unless you want your family to hate you
The pre/pro I use is a Marantz AV7005, and it's got a nice system where after you label the sources (so they show in the fluorescent display on the front panel) and then set it up to skip (delete) sources you're not using, then there's a rocker on the remote that steps through the enabled sources one by one, in a loop, so it's trivial for the fam (and me) to pick a particular source. No fooling around and no guessing. I do have a Harmony, but the Marantz remote sort of rendered it almost useless (I still use it to turn on the projector... stupid projector remote went nipples north about six days after the warranty expired... the harmony knows how to deal with the projector, so it sorta saved my bacon there.)
Now, the problem I have with my Harmony remote is that it's really, really slow. Even moving up and down in the projector menu takes about a second per entry or adjustment step in a brightness slider, for instance. The original remote was snappy. I dunno why it's so slow, but it sure doesn't make me want to use it. It really doesn't make me want to set up an external HDMI switch. I can just imagine the confusion when things get out of sync (yeah, I've seen the Harmony start to prompt... "are things ok now? how about now?"... yowza.)
The Marantz remote is a learning remote, etc., and I did set it up for a couple things, it seems to work fine. It's got some cool features, too, one I particularly like is you can tap a direct access source once (say, TV) and then the controls on the remote adjust that unit, but you have to tap it twice to actually switch to the source (this is above and beyond the rocker control.) So you can fiddle with stuff while on another source. It's kinda trick and I use it fairly often.
And: For gaming, if at all possible, try limit format conversions and extra help from your processor -- every step adds more latency.
LOL. Great story. I have a similar one; guitar hero and rockband really require good synchronization; took me a bit to get all that squared away so the games were playable. Yeah, you gotta watch whose scaler is on first, etc. And there are scalers in the game machines, in the pre/pro, and in the projector. It's like swatting flies sometimes.:)
So do you have a recommendation for a really, really good HDMI switcher with IR remote control? I'm convinced there are no good component switchers, I've got a heap of them and they all suck rocks. But I could perhaps get the HDMI systems (XBox 360 and PS3) onto something like that, then maybe add future systems to it as well, leaving the pre/pro to handle the older component units.
Probably should grab a copy of "cuteSDR" and get the linux version working (it's a QT project.) From there, build yourself an ethernet server for your chosen SDR (there are linux examples out there), and you're up.
So what's at 850-869 mhz of $400 worth of interest to you?
By the way, I live a few blocks from a commercial FM station and use the RTL-based dongles at present. I don't have any problems with overload, even when tuning 120 MHz (same band in the e4000 LNA). I don't think the dongles really have the problems you stated. They do have a lot of problems (particularly birdies, and a high noise figure), but the concern about overload is urban legend.
Not a legend at all. I use an outdoors discone for above 30 mhz; I'm about 5 blocks from the sheriff's department, and listening to 154.785 or 154.920, I get a huge desense when 155.385 (ambulance) is active. Probably the reverse too, though as I don't monitor the ambulance, I can't say. Even listening around 136 Mhz (WX satellites), I get de-sense when the railroad or sheriff's department fires up locally. That's with an RTL dongle and with the FUNcube, and FUNcube Pro+, all three. I can see the noise floor pump right in time with the signal. When I trap the (huge) ambulance signal out, the effect goes away.
Re your success with FM, your dongle may have an FM broadcast band trap. Or your antenna system might be doing it for you. Heck, your antenna cable might be doing it. RF is somewhat tricky unless you're pretty knowledgable. Another possibility is that you are seeing the de-sense as a constant thing; in that case, you wouldn't know until/unless they take the station off the air.
Also, just FYI, overload is a concern with any radio. Dynamic range is one of the key specs we look at. At some point, once the RF is too hot, radios get in (deep) trouble. Prior to that, they start to de-sense, etc. Depends on the design. An SDR, which depends on digitizing a wideband signal, will get in trouble if the signal exceeds the A/d's highest sample; at that point, all the detail goes out of the signal and the entire bandwidth being sampled is effectively poisoned. That's aside from what happens if there's an RF front end in there, filter(s), a mixer, etc., which quite often, there is.
LOL. Well, let's see. International shortwave broadcasts, both analog and digital. You know, news about other than the Kardashians. AM radio broadcasts (US and elsewhere, depending on your antenna systems.) Longwave broadcasts. Aero beacons. Military and utility monitoring. Solar flare monitoring. Monitoring ultrasonics, such as bats and insects. Submarine communications. Time stations. Citizens band. R/c device monitoring. Coast guard. Commercial marine communications. Weather reports (teletype, naxtex, FAX WX maps, greyscale satellite images.) All kinds of analysis of all of these. And yes, all kinds of ham radio monitoring too... you don't have to be a ham to listen and/or decode. There are eleven ham bands in the range 0-30 Mhz.
Just a brief overview, of course. HF is where the fun is, I assure you. I can monitor from almost DC to several GHz here, and HF is definitely where it's at as far as I'm concerned.
No, the reason is that TFS says "The frequency range to be covered is planned as 300MHz-3.6Ghz.", and "12-bit samples" and this is slashdot, pal. You're bloody lucky I read TFS. lol.
And given that TFS puts the F range at "why would I be interested in that?", and the sample depth at "yawn", why would I *then* go researching more about the unit?
As for my involvement, if any SDR manufacturer wants support, I've been willing to write it free of charge. Just FYI. I've probably put as many hours into the whole SDR thing as anyone you're likely to ever meet; but the fact is, there's an entire range of capabilities out there. This one, according to TFS, falls somewhat short. If TFS is wrong... well, then, perhaps you should be pestering the person who wrote TFS, eh?
Nope. There are still experimenters bands, ham bands, etc. There's even "the lost band" down in LF where we can fool with transmit capabilities without concerning ourselves with the FCC.
In the US, you can also broadcast at low power in the AM and FM broadcast bands, though there are some restrictions on antennas and so forth.
The FCC is basically the enemy of the people here; it spends its time making sure the RF spectrum is kept from the people and given wholesale to corporations. But they've not quite managed to kill off hams and experimenters. Yet.
Heck, there are a *lot* of brands of SDRs out there for sale. It's quite surprising, perhaps, but there it is. I own several.
The thing is, you can get far better performance out of a decent SDR than you can out of any analog radio ever made. For a fraction of the cost, and with features you could never have had.
Just think of the many radios that have sold in the past, then imagine all those people waking up to the idea that they can have tons more performance. Everything from AM radio and SW radio to ham radio and police monitoring... all for relatively cheap and *amazing* performance.
How different? You could have bought yourself an ICOM R-8000 for over ten thousand dollars... yet today, slap a little box down on your desk and *wildly* outperform the thing. For a few hundred bucks.
Every radio person I've been the first to show my SDR systems to has done the gape/jaw-drop thing. Every one. And well they should. My friend Bob told me "It seems like you're cheating":)
Nah, even knowing that, it's motivated by the fact that connecting the DAC to anything would be a royal PITA. There are SDRs out there that plug an play almost DC to L band; slap 'em into the USB port and get on with it.
Sorry, there are just too many good SDRs out there already that are basically plug and play USB or ethernet. 14 bit, 16 bit and more. A 12 bit SDR that doesn't get below 300 Mhz? Nah. Not really in the running unless you want to deal with the (very, very few) interesting signals above 2 GHz or so.
The little tuner sticks are cute. but RF wise, they stink. The best one is about $200, and it's just ok, though the bandwidth is amazing. You want a *good* SDR, go visit RFSPACE, that's bottom of the price stack, and they go up from there. There are *many* vendors.
For hams who want to transmit, check out Flexradio. A decent range of SDRs. All plug and play.
Slashdot Mirror
If you're running a website with Apache, you can configure Apache to look at the HTTP_REFERER header and see where the web surfer was when they made the request for the image. If they weren't on your website, (or if they don't provide the header, an act to be widely discouraged), just re-direct them to your home page instead of serving the image.
I would think that other web servers could do the same thing, one way or another.
For most people, it costs money -- perhaps not a huge amount, but still, real money -- to put up a website and serve content to the world. The expectation, if not agreement, is that you'll look at the site's content on the site.
The webmaster's position is no more hostile than that of the deep miner: There are expectations, but no promises.
Google's search goes far beyond fair use, as far as I'm concerned.
Exactly. At 60+, there aren't even any open doors if you are skilled.
There's talk -- you can get interviews -- but you won't be hired.
Here's how corporations really see it:
Older workers screw up insurance plans, are assumed to expect higher salaries (or to be discontented even if they claim they'll take a lower one), they have more extended families, they get sick more often, they take more time off, they're more chatty/garrulous, they won't integrate well with "the kids", they pose higher slip and fall risks, it's more difficult/stressful for them to travel, their knowledge tends to be stale... and you probably look like crap in a miniskirt.
Ok. WTF. I've been seeing that phrase for years now, and I *still* can't quite figure it out.
Where can I get this free beer? Because apparently, for some reason, my area doesn't have a source. I've looked and looked, and beer, even really lousy beer, just isn't available for free. Not even if you make it at home... you still have to come up with the ingredients. And bottles.
Would someone take a moment to explain this strange turn of phrase to an old dude?
In the physics of weapons, mostly. Without force, or the threat of force, the concept of ownership is meaningless.
Just like every other "right" you can name.
At some point, weapons and the threat of their use come into it.
That's what makes sure the things you left behind in the morning are most likely the same things you'll come back to in the evening.
In the US, in most cases, your land can be taken by the courts for any number of reasons. It can be taken if the government wants to build a road, or, in many states, if a corporation has a plan for your land that will earn more taxes than you are presently coughing up for the same parcel, or parcel plus its neighbors. So while you might think of the government as "backing" your property ownership, there are also many situations where the government is adversarial in that regard.
Well, the tradeoff for this apparent peace of mind, at least here in the USA, has been creating a situation where you can't defend your land from the remaining entities that want it. And, if your neighbor has enough money, that includes them, too, in any state that hasn't enacted specific types of laws controlling eminent domain, since SCOTUS took a pants-poopingly stupid position on the matter (in Kelo v. City of New London.)
All over Montana, for one, particularly out on the eastern high plains.
Huh. I thought the livestock were the ones doing the grazing. Of course, if the cattlemen's heads are down there cropping grass, I probably wouldn't have noticed them, so there you go. Slashdot: Where you can learn something new!
No, actually, we handed the government a monopoly on slavery and indentured servitude. The 13th amendment:
Considering the overwhelming nature of the web of law as it stands today... it's pretty easy to find yourself involuntarily making license plates, etc., for a corporation.
Related stat: At this point in time, about 3 million US citizens are jailed (about 1% of the population.) Furthermore, some prisons are moving to private ownership, so they essentially inherit the forced labor value of the prisoners.
The devil's in the details, as per usual.
Thanks, read every word. :)
Which is the opposite of the intent of US copyright (note this is not a US app/project), which is to, for a limited time (too long right now, but that's another discussion), secure the rights to the author so that eventually the work will promote progress. From the constitution:
In the US context, at least, this would work against such a thing. The way I see it, someone writes a book, eventually, that book should become part of the shared knowledge base, arts base, etc. I'm wary of a concept where a book is only available in part, where readers may never get the whole thing, and where e-readers... not exactly known for avoiding DRM and other such intellectual poison... contain the only (partial) copies.
A used book should be a treasure, something saved and valued and passed along. Electronic or not.
No sir, don't like it.
I think I retired in the 1990's
I don't exactly remember...
I have poopheimer's. That's where you forget shit.
Don't touch that! It's a pixel! A dirty, dirty pixel!
That's right. Just put it in the cloud. We'll take "care" of it for you. That's right. Sleep now.
My comment was spot on accurate, near as I can tell. So I'm perfectly happy to take it as "my fault".
If the thing starts at 300 mhz, as TFS says it does, then there's the basis for the comment.
As for the rest, ok, whatever. You have a nice day.
SDR performance advantages: ability to dig signal out of noise. Ability to remove noise. Ability to control the bandpass. Sharpness of filtering. Ability to see what's going on around the signal, and spot signals, in unbelievably low-signal or high noise conditions -- or both. Time division multiplex filters that pull out many carriers at one time and leave excellent audio behind. Ability to ID digital signals visually in just moments... every type of digital signal has a different spectral "signature", and so I know I'm looking at Olivia, or RTTY, or SSTV, or whatever. Ability to record, and play back, entire bands. High resolution realtime carrier analysis. Ability to remote the receiver head. Precision metering. Completely reconfigurable in seconds. Direct integration with all manner of analog signal processing (eg soundflower, Audio Hijack Pro, and just about every audio plugin you ever heard of.)
Ability to get right in there and code whatever feature you want.
I had a Yaesu FT-2000, with the DMU and speaker and all the goodies. My $500 SDR-IQ wiped that thing out. On the same antenna, it could pull signals out of the noise that simply were impossible to hear at all on the FT-2000. It eliminated noise the Yaesu couldn't do a thing about, not with DSP modes and not with the blanker. The bandpass control (shift, width) wasn't even remotely comparable to the ability to drag a razor edged upper or lower bound. I sold the FT-2000 and its accessories. It was pointless, just a ton of knobs and buttons that couldn't even come close to keeping up.
I also have an FT-980, an old school analog ham radio; also can't keep up, just hears noise, mostly.
Here, the FT-2000's (presumably) greater sensitivity was useless; the noise level was too high, and it couldn't get rid of it. The SDR-IQ, plus software, eliminates the noise, so I heard much more. Then, having heard it, I can isolate it better because of the bandpass.
It doesn't do you any good to have certain types of specs unless you have a pristine signal environment. And where can most of us find that? Unless... unless you have RF signal processing that's so good as to obviate the noise. And that's what sits on my desk.
The SDR-IQ is not a top of the line SDR; RFSPACE (and others) make much higher performance ones. Yet it just kills in operation. I'd like to try the higher end ones someday. But I know from using this that an analog radio just can't get there.
I have lots of other SW radios, receive-only, also. The FT-2000 was the best receiver, but I've been collecting them for years. None of them can touch the SDR-IQ.
And finally, all this at about the cost of the high-end microphone for the FT-2000, the MD-200.
I'm not really talking about "stick" type SDRs here. You need a decent front end, and you need stable, high resolution sampling to avoid various artifacts. But if you can meet that fairly low standard, it can be an eye-opener.
Also -- like any radio -- you need to know your way around the tools you have. Given that I wrote my own, it's fair to say that I'm an expert user. But I also spent a lot of time with that FT-2000, I can tell you, and it's limits were surpassed the very first day I put the SDR-IQ on the same antenna.
I can't help but notice that I didn't claim there was one. :) You do know what a "straw man" is, right?
CuteSDR is a great starter app that can be tweaked to work with anything. You didn't mention that you wrote your own code, just that you wanted "linux support", and inasmuch as that would mean, get ready, "software", I pointed you at the software that would support whatever hardware you wanted to run, which I had already assumed you had identified, because, get ready, you had said so. If, as you say, you write your own software, then "linux support" is pretty irrelevant, because you'll be doing the writing. I just figured you were looking for software because I'm unaware of any SDR with a "linux connector" or a "linux spectrum", ya dig? Consequently, I pointed you at something that had already done most of the difficult stuff. You're welcome, even if you're maybe kinda working a bit too hard at missing the point.
I see. Something commercial, then, from the secrecy, etc. Good luck with the project.
"trap" -- typo, dunno if it was yours or mine, too lazy to look. A trap can be as simple as a coil and a cap, especially in this kind of setup. Small, too, at 100 MHz or so. Nothing expensive.
Are you having a bad day? My sympathies, if so. You seem to be grasping at the idea I'm your adversary. I'm not. I'm just some guy on the Interwebz.
No. I'm talking about CW format beacons. They're all below 540 kHz. Very useful to see what LW prop is going on.
Well, sure. That's the way everything is, isn't it? I'm answering you from my perspective, because you asked me.
Yes, tons of 'em. Not just out of the US, either. You can also see spectrum probes sliding across the various portions of HF; hear mystery "coded" signals (numbers stations), even see some weird stuff that's (thus far) eluded any explanation, like slow carriers that transit the 49 meter SW band, right through the commercial stations and a very sedate and extremely stable pace. No idea what that is. Just find it interesting.
LOL, thanks.
All you do is for your "antenna", you hook up a tweeter or a supertweeter, and hang it out by your eaves, attic entrance, etc. Feed that to the SDR-IQ. All manner of hilarity ensues. Including the lady of the house going "what, bats? We have BATS?!?!?"
Well, they're also typically frequency references. You can do a number of things with them. First, they tell you about propagation (because they're always on, so you know what's on bounce by what you can hear.) You can do some cool experiments like these. They give you deep sea weather reports, too. WWVH (Hawaii) and WWV (Colorado) give you an instant tip because one uses a womans voice, the other a mans. You can tell how prop is going by what you hear. There is also BCD coded time on there. And many nations have time signals, if you know where they are (and my software does.)
Well, yes, exactly. CB is bloody hilarious to listen to. At least to me. And it also, because it's so busy, serves as another type of prop indicator. Even if the ham bands are dead, for instance, you can tell they are open, just not in use, when the CB bands are open.
What it tells me is that it's time to go outside and check the skies for our local air club, so I find it quite useful. Think of it as a "beacon for fun." I can also tell the guys if they're making a mess - too broad, etc. Listening is not everything; analysis and reaction is interesting as well.
Ok, great. More power to you.
Dude, seriously, don't blame ME for slashdot moderation. It's totally broken and I've said so for years, but in any case, I didn't mod the darned post myself so I don't see how I should accept any blame for it whatsoever. Seriously. The mods here are only on crack when they aren't on meth. It's something in the perl code. Nasty stuff. As for the first post, I saw the story (twitter
The pre/pro I use is a Marantz AV7005, and it's got a nice system where after you label the sources (so they show in the fluorescent display on the front panel) and then set it up to skip (delete) sources you're not using, then there's a rocker on the remote that steps through the enabled sources one by one, in a loop, so it's trivial for the fam (and me) to pick a particular source. No fooling around and no guessing. I do have a Harmony, but the Marantz remote sort of rendered it almost useless (I still use it to turn on the projector... stupid projector remote went nipples north about six days after the warranty expired... the harmony knows how to deal with the projector, so it sorta saved my bacon there.)
Now, the problem I have with my Harmony remote is that it's really, really slow. Even moving up and down in the projector menu takes about a second per entry or adjustment step in a brightness slider, for instance. The original remote was snappy. I dunno why it's so slow, but it sure doesn't make me want to use it. It really doesn't make me want to set up an external HDMI switch. I can just imagine the confusion when things get out of sync (yeah, I've seen the Harmony start to prompt... "are things ok now? how about now?"... yowza.)
The Marantz remote is a learning remote, etc., and I did set it up for a couple things, it seems to work fine. It's got some cool features, too, one I particularly like is you can tap a direct access source once (say, TV) and then the controls on the remote adjust that unit, but you have to tap it twice to actually switch to the source (this is above and beyond the rocker control.) So you can fiddle with stuff while on another source. It's kinda trick and I use it fairly often.
LOL. Great story. I have a similar one; guitar hero and rockband really require good synchronization; took me a bit to get all that squared away so the games were playable. Yeah, you gotta watch whose scaler is on first, etc. And there are scalers in the game machines, in the pre/pro, and in the projector. It's like swatting flies sometimes. :)
So do you have a recommendation for a really, really good HDMI switcher with IR remote control? I'm convinced there are no good component switchers, I've got a heap of them and they all suck rocks. But I could perhaps get the HDMI systems (XBox 360 and PS3) onto something like that, then maybe add future systems to it as well, leaving the pre/pro to handle the older component units.
Seriously? LOL... what part do you "not believe", O doubtful one? Perhaps I can shore up your faith in mankind. :)
I should also have mentioned that LF, MF and HF signal propagation is endlessly entertaining. If you roll that way. I do. :)
Probably should grab a copy of "cuteSDR" and get the linux version working (it's a QT project.) From there, build yourself an ethernet server for your chosen SDR (there are linux examples out there), and you're up.
So what's at 850-869 mhz of $400 worth of interest to you?
Not a legend at all. I use an outdoors discone for above 30 mhz; I'm about 5 blocks from the sheriff's department, and listening to 154.785 or 154.920, I get a huge desense when 155.385 (ambulance) is active. Probably the reverse too, though as I don't monitor the ambulance, I can't say. Even listening around 136 Mhz (WX satellites), I get de-sense when the railroad or sheriff's department fires up locally. That's with an RTL dongle and with the FUNcube, and FUNcube Pro+, all three. I can see the noise floor pump right in time with the signal. When I trap the (huge) ambulance signal out, the effect goes away.
Re your success with FM, your dongle may have an FM broadcast band trap. Or your antenna system might be doing it for you. Heck, your antenna cable might be doing it. RF is somewhat tricky unless you're pretty knowledgable. Another possibility is that you are seeing the de-sense as a constant thing; in that case, you wouldn't know until/unless they take the station off the air.
Also, just FYI, overload is a concern with any radio. Dynamic range is one of the key specs we look at. At some point, once the RF is too hot, radios get in (deep) trouble. Prior to that, they start to de-sense, etc. Depends on the design. An SDR, which depends on digitizing a wideband signal, will get in trouble if the signal exceeds the A/d's highest sample; at that point, all the detail goes out of the signal and the entire bandwidth being sampled is effectively poisoned. That's aside from what happens if there's an RF front end in there, filter(s), a mixer, etc., which quite often, there is.
LOL. Well, let's see. International shortwave broadcasts, both analog and digital. You know, news about other than the Kardashians. AM radio broadcasts (US and elsewhere, depending on your antenna systems.) Longwave broadcasts. Aero beacons. Military and utility monitoring. Solar flare monitoring. Monitoring ultrasonics, such as bats and insects. Submarine communications. Time stations. Citizens band. R/c device monitoring. Coast guard. Commercial marine communications. Weather reports (teletype, naxtex, FAX WX maps, greyscale satellite images.) All kinds of analysis of all of these. And yes, all kinds of ham radio monitoring too... you don't have to be a ham to listen and/or decode. There are eleven ham bands in the range 0-30 Mhz.
Just a brief overview, of course. HF is where the fun is, I assure you. I can monitor from almost DC to several GHz here, and HF is definitely where it's at as far as I'm concerned.
No, the reason is that TFS says "The frequency range to be covered is planned as 300MHz-3.6Ghz.", and "12-bit samples" and this is slashdot, pal. You're bloody lucky I read TFS. lol.
And given that TFS puts the F range at "why would I be interested in that?", and the sample depth at "yawn", why would I *then* go researching more about the unit?
As for my involvement, if any SDR manufacturer wants support, I've been willing to write it free of charge. Just FYI. I've probably put as many hours into the whole SDR thing as anyone you're likely to ever meet; but the fact is, there's an entire range of capabilities out there. This one, according to TFS, falls somewhat short. If TFS is wrong... well, then, perhaps you should be pestering the person who wrote TFS, eh?
Nope. There are still experimenters bands, ham bands, etc. There's even "the lost band" down in LF where we can fool with transmit capabilities without concerning ourselves with the FCC.
In the US, you can also broadcast at low power in the AM and FM broadcast bands, though there are some restrictions on antennas and so forth.
The FCC is basically the enemy of the people here; it spends its time making sure the RF spectrum is kept from the people and given wholesale to corporations. But they've not quite managed to kill off hams and experimenters. Yet.
...of which there seem to be a very large number.
Heck, there are a *lot* of brands of SDRs out there for sale. It's quite surprising, perhaps, but there it is. I own several.
The thing is, you can get far better performance out of a decent SDR than you can out of any analog radio ever made. For a fraction of the cost, and with features you could never have had.
Just think of the many radios that have sold in the past, then imagine all those people waking up to the idea that they can have tons more performance. Everything from AM radio and SW radio to ham radio and police monitoring... all for relatively cheap and *amazing* performance.
How different? You could have bought yourself an ICOM R-8000 for over ten thousand dollars... yet today, slap a little box down on your desk and *wildly* outperform the thing. For a few hundred bucks.
Every radio person I've been the first to show my SDR systems to has done the gape/jaw-drop thing. Every one. And well they should. My friend Bob told me "It seems like you're cheating" :)
Nah, even knowing that, it's motivated by the fact that connecting the DAC to anything would be a royal PITA. There are SDRs out there that plug an play almost DC to L band; slap 'em into the USB port and get on with it.
Sorry, there are just too many good SDRs out there already that are basically plug and play USB or ethernet. 14 bit, 16 bit and more. A 12 bit SDR that doesn't get below 300 Mhz? Nah. Not really in the running unless you want to deal with the (very, very few) interesting signals above 2 GHz or so.
The little tuner sticks are cute. but RF wise, they stink. The best one is about $200, and it's just ok, though the bandwidth is amazing. You want a *good* SDR, go visit RFSPACE, that's bottom of the price stack, and they go up from there. There are *many* vendors.
For hams who want to transmit, check out Flexradio. A decent range of SDRs. All plug and play.