- some cryptobro
/s
From a quick Google I see that HFT carries out trades in an average of 700ns, which is close to the cycle time of a 150kHz carrier, so you'd have to come up with some really clever phase modulation scheme that could carry meaningful data in *one single cycle*.
You're definitely going down the SDR route for that.
At least in VK/Australia, there’s the 2200 meter band, but it’s quite limited (1W power limit, CW/digital only, 135.7–137.8 kHz).
At the same time, as much as I don’t want the AM broadcast band to die, I’d love an amateur band in the lower/middle part of MF/MW.
I meant just the broadcast band 148.5-283.5 kHz. (Though I'd love if 2200m and 630m were just a bit wider.)
> and NDB beacons.
Good point[1]. So 148.5-200 kHz in ITU Region 2 (and keep LowFER allowances on 160-190kHz as a consolation prize.)
We've also got a chunk just off the bottom of MW around 475kHz, which ought to be good for long-range night-time communications. It's licenced for CW, QRSS, and narrow-band digital modes.
Doesn't GPS utterly replace this?
Building equipment that works on frequencies this low, and avoiding natural interference, can be extremely difficult.
Actually generating the signal you could do with a moderately expensive USB soundcard, directly synthesizing it with simple VST-like plugin. Mad to think about, really.
There's also high frequency firms that want to muscle their way into shortwave frequencies as they can have lower latency between trading sites (eg NYC and Chicago) since the physical infra isn't a direct link as the crow flies (as well as the speed of light being slowed in fiber optic lines). They've even restarted some microwave links, as they don't necessarily need a lot of bandwidth, just latency.
My 7 Mhz antenna (HF, 40m band) is 67 feet long, and goes across by whole house.
The smallest antenna you could get away with for LF would be hundreds to thousands of feet long.
You might be able to go smaller if you enjoy suffering. Though, there are some pretty creative antenna designs that defy logic.
I wonder if you can couple to your local distribution grid, and not get arrested.
Coupling into my power upstairs is a bit of a problem sometimes though.
Pirating power is something I've heard that happens, but I looked it up, and couldn't find an actual cited example of someone doing it via induction.
Plenty of people doing it via extension cords and device tampering though.
I haven't worked with my end-fed on 40m for a couple of years. We've recently all had our crappy old aluminium-cored BT lines replaced with shiny new fibre though, so this time I am unlikely to lift the coveted Worked All DSLAMs trophy ;-)
The next logical step in that direction would be cracking down on HAM, not liberalization of it.
We'll see.