radar signal detector, horn design (Encyclipedia of electronics circuits vol.2 p.520)

[intruder]

Hi,

I would like to know if somebody there has done the deluxe radar
signal detector from radio-electronics circuit (with the 1458 & LM
386).
I need to have some info concerning the horn design,I want to get the
signals from one direction, also, is there a practical way to trim
C1's leads for the desired frequency ?
My goal is to intercept the radar signals of ships.

Thanx

 

[John Todd]

Hi,

I would like to know if somebody there has done the deluxe radar
signal detector from radio-electronics circuit (with the 1458 & LM
386).
I need to have some info concerning the horn design,I want to get the
signals from one direction, also, is there a practical way to trim
C1's leads for the desired frequency ?
My goal is to intercept the radar signals of ships.

Thanx

X-band marine radars operate at about 9.6GHz; the waveguides
measure about 7/8 inch by 3/8 inch inside. A metal enclosure near this size
closed at one end and 2 inches long, with a 1N23 microwave diode
mounted across the short dimension, about 3/8inch from the end,
will do what you want. If you really want a "horn" appearance,
taper the open end out at a 45 degree angle on each side for
an additional inch or so.
I haven't seen the article you mention, but the components
listed are not microwave capable. The 1458 will be a DC amp,
and the 386 probably a beeper. C1 is more likely a filter,
developing DC from rectified RF. The only "tuning" would be
the position of the diode, so maybe you could mount the ground
end in a slot, so you can minutely vary the distance to the
closed end of your waveguide.

 

[anc]

Hi,

I would like to know if somebody there has done the deluxe radar
signal detector from radio-electronics circuit (with the 1458 & LM
386).
I need to have some info concerning the horn design,I want to get the
signals from one direction, also, is there a practical way to trim
C1's leads for the desired frequency ?
My goal is to intercept the radar signals of ships.

Thanx

I'm not sure which circuit you have made, is it similar to this link :

http://www.uslink.net/~cybercir/cir2.htm

With this circuit C1 is tuned by its lead length, however I made one last
night and tested it today in the UK, not sure of the actual frequency of
static (Gatzo) road radar cameras, but thiss circuit did "blib" about twice
a second when passing one speed camera on the M62. However I also found
out I get a response from mobile phones (980MHz) in close proximity so
either my tuning is out or maybe I have a weak battery.