How to build a small radar?

[coolchip]

Any ideas/help/links?

Thanks!

 

[fastelec]

will you specify more?
i mean range,minimal distance,frequency and so on.

 

[flatulent]

There are also the laws to consider. You can only operate in unlicensed bands and the laws in some countries do not allow pulsed operation in these bands. You will be restricted to Doppler type systems either monostatic or bistatic.

 

[eddyboy]

I am also looking into constructing a small radar, but for weather, similar to the usa weather radars.
Being a licenced radio amateur, I may be able to use certain microwave freqs.....

thanks
eddy

 

[FANT]

To build a wheather radar you need a lot of power and this is not allowed on many countries.
Also the frequencies used are quite high and you need a lot of experience.
Last take care not to interfere in the other transmissions because the laws are very strict in this field and overall if you disturb the military frequencies ( very common in X band ) you will be in trouble.

Mandi

 

[eddyboy]

I can use frequencies as high as 24ghz....and beyond....
The power level does need to be too high as its not for extremely long range......maybe 2 miles max.
I want to look at the contents of storm cells as they pass overhead.....

JOHN

 

[scoppulal]

I think that 2.4 GHz is a good band also for buying commercial
moduls.
It allows you to have "small" antenna for a bistatic solution
that I think is much easier to build.

Of course you should know the laws in your country before
start using a radar

 

[eddyboy]

do you know of any commerial units and the url

thanks

 

[batdin]

Pardon me,but how do you intend to make a 3D-scanning antenna?
(weather radars are 3D-radars)
For weather radars higher frequencies are preferable because the echo is stronger.
The difference between reflection properties at 2GHz and 4GHz is 16 times!
But it is not a JOKE to make a weather radar.Even a short-range one.

 

[Slackvision]

I worked on a tubed radar in the air force. You might be able to find them for sale online since they are currently obsolete. The nomenclature was "FPS-77".

If you get one, be prepared to pay a heafty shipping fee and an equally heafty electric bill.

 

[puviarasu]

Can it is possible to build radar which uses signals in range of RF ?

 

[Slackvision]

The one I worked on was rather crude. It was basically ping and listen at 5.5xxGhz using a large magnatron for the transmitter and a small klyston for the heterodyne circuit. If you can get a transmitter that can run at 100watts or more, it shouldn't be too hard if you are up to snuff on electromagnetic fields and radio theory.

 

[coolchip]

Thanks for answers.I just want to build a small working model with any range for demonstration purposes.Is it possible ?

 

[FANT]

About the transmitter section, you can use the magnetron of a microwave oven, if you decide to use 2,4 GHz as working frequency.
Output power is about 500 W.

Take a lot of care about the high voltages used to fire the tube.

Mandi

 

[scoppulal]

For a commercial solution you could visit ham related web sites,
they have also stuff for 5GHz.

I don't think you could build a 3D radar, but with a very simple equip.
you could be able to measure echo delays and thus distance from rain or other
(I would suggest to think to 10 GHz... you may find pieces of equipment from hams
they home brew their stuff at that frequency).

Just an idea.

Ciao

 

[FoxyRick]

coolchip,

You might be able to find an old radar intruder alarm sensor, these were quite common before good body heat sensors become popular. These have most of the needed electronics on the main unit with the transmit and receive horns. They are doppler (so detect movement towards/away from the radar, rather than giving a distance measurment) and give a signal proportional to the velocity. You might be able to redesign them for pulse mode, certainly you have all the main necessary bits already made.

For a nice demonstration, I would imagine they are ideal. They come up on eBay every so often, one day I might get one myself. I used to play Paintball and always wanted a small, portable radar to detect incoming enemy.

I can't find a complete one on eBay at the moment to show you, but someone is selling one of the horns removed from the complete module.

**broken link removed**

Hope this gives you some ideas,
FoxyRick.

 

[angie-filt]

Hi

Try this one, from Ham radio.

Angelo.

 

[jojokatada]

Hi

Try this one, from Ham radio.

.

just only scan text not helpful no schematic

 

[anun]

does it work???

 

[FISHMAN12]

Does anyone know how to build or find schematics on how to build a small dopplar radar system.

Thankyou