Cost of the Cheapest LoFi AM Transmitter ~ 20 - 30m Range

because they are resellers.

AM broadcast band? Chances are if you had to buy all new parts and build it yourself you'd spend more than $3.

I built those in the 50's. The 3.5 mhy choke I used might be more than 3 bucks today, and back then transistors were more expensive.

Thanks.

A mic isn't necessary -- just a tone to warn motorists that a cyclist is around the curve.

Components are nearly free these days. I doubt it'd cost me a cent to hairball a small transmitter. Those with no stock or knowledge would need to pay retail though.

You might consider Shark Tank. There are no patents on this AFAIK.

I'm too lazy for it. I'm extraordinarily lazy. I'm so lazy I'm gonna develop a low [near zero] maintenance bicycle even if it works me to death.

An epic battle is raging within: The irreversible force lazy vs the immovable object lazy.

So, being lazy, other than batteries, any time I do anything that involves electronics I assume 0 cost and, if power is involved, 100% efficiency.

Batteries gonna make me drink a cup of coffee, start a spread sheet, ruin my _entire_ morning . . .

So why use AM, why not BLE?

Radio amateurs, back in the heyday of home-brew, would make little AM transmitters operating from batteries so they could have "hidden transmitter hunts," with home-brew radio direction finding rigs.

The government still does the same things - on an industrial scale. I suspect they are using angle of arrival and time of flight to achieve the same thing fancy antennas alone used to do. (that's based on their abandoning the large circular antenna arrays that used to do the same thing, called a Wullenweber array)

they could just be using movable beam antennas like amateurs do,

s around the curve.

I thought high frequencies wouldn't go around buildings, rock cliffs on cur ves and through thickets of trees like lower frequencies. The engineer at the FCC seemed enthusiastic about AM.

As many motorists have smart phones as AM radios so, if it can be made to w ork, it might be just as easy to implement. Then you could listen to the r adio and get cyclist alerts on the PDA at the same time.

My niece-in-law just got a bicycle for Christmas. She suggested something more sophisticated than binary, an indication of distance. Maybe several b eacons or several different frequencies on the cyclist could provide locati on info to motorists.

It's really critical to know which lane the cyclist is in on "California Hi storical Highways" -- one mistake and yer history. All California is doing now is putting up "Share the Road" and cardboard "3' clearance is the law" signs which is almost insulting.

It may be easier to get some N. European country to do this first. I've go t exactly zero pull in Sacramento.

Bret Cahill

Not the way they do it. They have a radar type display and used a goniometer to "give rotating properties to stationary antennas" and had excellent triangulation accuracy. Several operators could sit at consoles and monitor different frequencies with the same system in real time. The op would just position the curser on the signal and read out the bearing. Speed and accuracy count when you are dealing with search and rescue, etc..

Those amateur antenna were only suitable for a single, relatively high frequency, and didn't have globe-spanning accuracy. A high tech game of hide and seek. The transmitters were disguised and put in hard to reach places, so you couldn't just drive right to them.

that's a good point.

I've not seen any smart phones that could receive AM. and none that could receive FM without an external antenna.

they do something similar with aircraft.

Be aware that this will also be applied to pets and pedestrians, because people are selfish.

Insulting to who? the aluminium smelters who voted for trump?

The simplest fix for invisible cyclists is to reduce speed until the become sufficiently visible, next simplest is separate roads for cyclists.

Traffic networking (which this seems a precursor to) is still a way in the future.

That would be for a Bluetooth version.

You get more fatalities cycling than flying. I've been sideswiped twice at freeway speeds and once in an intersection trying to stay out from under the tires.

Nothing like that has ever happened flying. Of course, I cycle more than I fly . . .

Motorcyclists could use it as well.

Cyclists.

Motorists won't reduce speed.

That's very very expensive, politically impossible.

They could do it almost overnight. The lowest of the low hanging fruit.

Bret Cahill

Where is the insult?

Driving at unsafe speed is legal? it sounds like you have an enforcement problem there.

So I'm driving along listening to spotify, and what happens?