diy microwave alarm

Haven't seen any DIY but before you try to re-invent the wheel you might want to consider how you are going to design a microwave perimeter intrusion detector that will ignore bugs, birds, animals, blowing leaves, snow, and plants moving in the wind.

Also, when fooling around with microwave emitters ..... "you can put your eye out".

It is explicitly *not* my intention to re-invent 'the wheel'. That's why I'm asking for links to successful (hence useful) diy projects, i.e.: projects that are completed and available for copying.

Re other-than-human objects: I think those absorb a lot less energy than humans, except for cows and the likes of course. But then, who wants a cow in his strawberry field?

Yes.

Thank you for your thoughts,

joe

I mention those events and the "re inventing the wheel" because even those products that have been designed years ago and developed and improved over the years still suffer from false alarms due to these types of environmenta l issues. There have been a few of mfgs who have tried to market "electroni c fence" devices for residential use but have not been successful for just those reasons.

Because of the high rate of false alarms, the usual usage of these types of detectors are in situations where it is used in conjunction with video con firmation and on site guard response.

Photo electric eyes seem to have a better record but for it to be less fals e alarm prone and require less attention, it can get expensive. The use of multiple beams and a lot of tinkering and adjustment is required to be abl e to filter out the many false signal events ..... which, of course makes i t more prone to being defeated by someone entering with a purpose. The bett er units have fog, snow and other compensation circuitry to help reduce fal se alarms. Look at Optex line of products.

Sure, just bypass the door safety and turn it on by remote when the alarm is activated. While it won't stop the immediate problem it should have a long term affect on the rate of reproductive mutations. Hopefully these genes which produce thieves will be among those harmful mutations that die out as more beneficial mutations are maintained in the growing root stock.

Sounds pretty simple to me, but you will have to wait half a dozen generations to see the benefits of your DIY microwave alarm.

Now that's exactly what I'm talking about.

How about heavy rain...

thanks

I don't think you really are responding to *my* post :)

cheers

You don't want a DIY microwave alarm?

Let me just say: There is no door in a strawberry field :)

cheers

There is on a microwave.

Yeah, well, that's what you get when you (Americans) give the devices the name of their physical working principle, instead of their function, as is customary elsewhere (in Europe): 'microwave' vs. 'microwave oven'. (Pun intended :)

You would prefer that Americans were more verbose?

"We're about to be over run! What should I do?"

American, "Shoot the bastards."

European, "You must first weigh the merits of defending yourself against the certainty of arrest by agents of the government for both possessing and utilizing a method of defending yourself against an oncoming attacker versus the merits of remain alive long enough to do so by making proper and optimum use of your illegally possessed Webley revolver to strike by explosive acceleration of a projectile as many as six, or half a dozen if you prefer, of the oncoming horde depending on your skill, accuracy, and nervous level to remove some of the threat by use of force thereby ridding the third planet of this solar system colloquially called Earth and occupied by humans among a host of other life forms from a harmful infestation some of whom may be children of descent of unwed parental stock."

Hmmm.. pun-ishment huh?

I would just use a CCTV system with motion sensing. You can cover huge areas with few cameras for that type of use. Make sure the DVR has external contacts to trip whatever annunciation or actionable device you are planning to use once something is detected. At least you'll have a picture to go by if someone is stealing fruit!

Are you just trying to be notified if a person is roaming the field? Why not PE beams along the fence line? Or infrared/microwave combo units if you are going to use lots of short-range detectors? That will drastically cut false "alarms".

Three acres is a lot to cover, and microwave sensors would be way down on my list to consider (if they even made the list). You're looking at range issues, false positives, undetected positives, and a general pain in the ass all the way around.

Jeeze Bob, that was pretty good.

I could hardly understand your accent.

Now _that_ was verbose :)

Prohibitively expensive.

Why? There is a guard ready to shoot him right away :)

Yes!

YES! That was what I was looking for: (successful) DIY designs for these. Or even reverse engineered would be ok.

(What is a 'PE beam'?)

Again, costs should not become prohibitive.

I think the 3 ha (hectares) that I mentioned is even a much larger area (3 x 100 m x 100 m). So yes, it _is_ a lot to cover, but luckily we only have to cover the boundaries (totalling about 800 meters).

Yes, I admit we have a problem :/

Oh, you mean like saying microwave alarm instead of microwave motion detector for an alarm system?

Photo-electric

Read the O.P., it's all written in clear language what I meant to (and did) say :)

PE beams would be fine if they could span about 200 m in heavy rain.