Why is that expensive? It obviously can't require fancy hardware if it can also be done in software.
Imagine trying to design a calculator that isn't allowed to display the digit '8' on its LCD display.
In software, the implementation sees if the LCD is being set to a value that contains '8' in binary and if so, ignores the input.
In hardware, you have to have a camera that is pointed at the LCD, and a hardware OCR implementation that looks for the 8, and then a circuit that when the OCR implementation sees an 8, turns off the display.
1. If you have a single radio unit, you can easily do the "software" implementation where you look at what you're going to be broadcasting and cut it off if it's not legal. The problem comes when you have separate radio and amplifiers - the amplifier has no idea what whether you're feeding it 10M or CB frequncies. It will amplify either just fine, so the FCC really prefers you to build in a "hardware" type implementation there (a frequency analyzer that figures out what's going into it). It's just expensive to do so - like if you didn't already have a digital amp, you might easily add 1/4 or 1/2 to the cost just to get some dumb logic built in. And you can still probably get around it if you really try.
2. There is a disproportionate amount of cheap gear and old gear in circulation. We didn't get "smart" rigs until the late 90s at a minimum, and even so they are vastly outnumbered by stuff from the glory days of the 50s, 60s, and 70s. There has always been a relatively small amount of high-power stuff in circulation, and there's even less smart high-power stuff. A lot of the modern kit-built stuff like the Elecraft K2 focuses on QRP (effective operation on low power) instead of crazy high output.
3. This manifests as a CRAZY price curve. It's relatively easy to get an old radio from the 70s that'll do 50 or 100W (especially after factoring in weak, aging tubes, etc). A modern mini-rig that will do 25W or something is also relatively affordable. But if you want something new, powerful, or new AND powerful you can easily jump into the thousands of dollars. For the cost of a modern rig that'll do any given power level, you can afford an older rig and an amp that will put out an equally good signal with substantially more power. Or with a better antenna. And so on.
4. There's nothing wrong with the old gear and things like tubes can be fixed. If you trash your new wünder-rig it's garbage. So given that amateurs are crafty people (the proto-hacker, really) there's a strong incentive to make the old or lower-power stuff work, because it's repairable when it breaks.
Why is there significant expense in putting a ROM chip between the radio and the amplifier that cuts out certain frequencies? I can see where that's not as simple as mandating software that is simply incapable of generating bad frequencies in the first place, but it intuitively strikes me as the same sort of embedded programming that goes into, say, a microwave oven--I can see it adding some cost, but not so much that it would be unfeasible in e.g. an home wifi router. What am I not understanding?
The list of blocked frequencies changes occasionally (like time zone definitions); if you can't update the "illegal frequency blocking" chip then it becomes illegal to use your otherwise-perfectly-good product once the rules change. Plus, it depends on what country you're in, so ideally if you move (or just go on a vacation) to another countries you don't want to have to throw away your old router/smartphone/smartwatch and buy new ones in the other country.
Adding a protection device merely shifts the problem (being discussed) from the radio to the protection device.
It achieves exactly nothing.
An example of the former is "homemade AM radio", where you wrap a lot of wire in a coil, and changing where you complete the the circuit along the coil allows you to "tune into" different frequencies.
An example of the latter is the cantenna, a directional antenna that can be made from a Pringles can.
With the help of an auto-tuner to match the SWRs there's no physical reason I can't transmit/receive bands I'm not supposed to. It's not like tweaking a VFO is really a technical challenge, they're well-understood technologies. And the frequency display on my radio is literally just a frequency counter for my own edification, the base TS-820 non-S model doesn't even have one. To find your frequency you look at the dial, there's a printed scale for your band. You know what happens if you are pushing the limit too far? The FCC tracks you down and you get a pink slip telling you that they know what you're up to.
You both underestimate what older radios can do, and overstate what newer radios can do relative to them. The reasons that you didn't see people transmitting off-band before was primarily social, not technological. As for receive, the FCC was flipping out about people intercepting cellphone calls on omniband radios - 15 years ago. Omni SDR was around 10 years ago too, with the same capabilities (see: GNU Radio), it just cost more than $10 for a rig.
>Wideband radios are not all that new.
No, but super cheap ones are.
>It's not like tweaking a VFO is really a technical challenge
Well, it's a little bit of a challenge for most (especially non-hams), but sure, there's no magic involved.
>The FCC tracks you down and you get a pink slip telling you that they know what you're up to.
I've heard so many scary stories about the FCC, and yet their enforcement actions page is relatively empty; and hams are always heard complaining about both persistent abusive behavior that the FCC either does little, or is powerless to stop. My impression is that violators, both abusers and unintentional get a lot of chances to correct their behavior; and that FCC enforcement is mostly a paper tiger that can do a bit of damage to someone who wants to comply (for the most part), and can do very little or nothing to stop the worst abusers.
Enforcement actions: https://transition.fcc.gov/eb/AmateurActions/Welcome.html
Warning Letters: http://transition.fcc.gov/eb/AmateurActions/Legacy.html
>You both underestimate what older radios can do, and overstate what newer radios can do relative to them.
I don't think so. I know that these features, or reasonable substitutes for them exist/have existed for some time, but I also know that their widespread use was limited, primarily due to cost. Economies of scale in manufacturing mean that since a TV tuner chip which produced in the billions can be used as an SDR, now there are lots of very inexpensive SDR units available for purchase. For higher end equipment, there is also the fact that DSP tech has advanced at a pretty incredible pace enabling things like the ~$300 dollar 100MHz oscilloscopes in my lab and also the 500MHz scopes in my lab that didn't cost more than our minivan. Sure, many (maybe even most) of the things that can be done with an SDR can also be done with solder and wires, but an SDR can do any/all of them. A super cheap (as in < $10) SDR can act as a frequency analyzer (to use GP's term) can compliment a high quality analog radio design. I suspect that one could add that kind of feature to an analog radio and keep the total additional cost under $10.
>The reasons that you didn't see people transmitting off-band before was primarily social, not technological.
I think you've hit the nail on the head here. There simply isn't any/much of a problem, and where the problems do exist the FCC is largely toothless anyway (and that's arguably a good thing). The FCC sees the potential for cheap consumer equipment that can easily be made non-compliant; they know that they haven't the resources to enforce the rules against millions of people and want to simply prevent it from happening. There is a reason that the FCC has so little enforcement is because nobody who knows them, likes them.
>FCC was flipping out about people intercepting cellphone calls on omniband radios - 15 years ago.
Another reason to dislike the FCC, they made a rule which was almost totally ineffective, and today is completely moot; because the technology prevents the problem that the rule was supposed to prevent. The cost of scanners/radios went up, and some good products were taken off the market and replaced with junk, or simply not replaced. Yay FCC.
> Omni SDR was around 10 years ago too, with the same capabilities (see: GNU Radio), it just cost more than $10 for a rig.
A lot more than $10, and you had less "SD" for your SDR because your PC and the software was simply less capable. Now, a relative noob can start from practically nothing and point and click his/her way to receiving any number of things in an afternoon.