1090 MHZ AERIAL

 

The measurements are not absolutely critical but stick to them as close as possible, especially as regards the vertical element , there is no gain in making  it longer in fact if you were to make it 120 mm you would in effect reduce its efficiency ( i.e. it's range )  by quite a bit.

I have  used a  lna ( low noise amplifier )  for ads-b   but I would suggest that firstly you improve your ant system and place the ant as high and in the clear as you possibly can, don't think that by using a lna  that it will  improve your ads-b catchment area when in reality  the ant is poor or badly  located. Also the device itself can induce an unacceptable noise level

 If you use an lna always locate it near the ant preferable with only a few inches of co-ax from the ant to lna input.

Also note that not all lna can be powered by a power inserter. The lna manufactured by 9a4qv is ok but I think you need to ask for it to be power inserter enabled.

The above ant works ok - but it is  a bit flimsy and ideally  mounted inside

 

SIMPLE 1090 MHZ ANTENNA WHICH WORKS VERY WELL

 

If you are using the original aerial that came with the rtl dongle for ads-b reception then  it is to long, you need to optimise it for 1090 mhz i.e cut it down to about 69 / 70 mm.

 

                                                                                                               

136.963 MHZ VERTICAL DIPOLE

I have also made one of these dipoles for 1090 mhz, about 5 inches long in the tube with each leg being slightly longer than 2 inches , works ok especially if you mount it on a pole outside

A SIMPLE J POLE ANT FOR 1090 MHZ

 

 

I made it out of 1mm brass tube - I soldered it at the two bottom corners (or you could just try to bend it) it can then be placed inside a piece of plastic tubing

The good thing about this ant is that it does not require a ground plane - place it as high as you can

 

SLIM JIM ANT FOR AIS ON 162 MHZ

I MADE THIS OUT OF COPPER TUBING - ABOUT 2 MM IN DIAMETER - SOLDERED AT ALL OF THE CORNERS AS IT WAS TO FLIMSY TO BEND

 

COLLINEAR ANT FOR 1090 MHZ

 

This ant is very cheap and easy to make and performed a lot better than I thought it would - I made it out of enamelled covered  copper wire about 2.5 mm thick - not sure what the 'swg ' was

Brass/copper tubing would make it more robust but I think there would be problems with the 'bends' it will tend to flatten out

 

 

MORE SIMPLE COLLINEAR ANT FOR 1090 MHZ

 

 

Need to mount your antenna some distance away from your raspberry pi ?   the best antenna for 1090 ads-b reception for most of us in far from ideal locations is probably the antenna which came with the radar box or a similar commercial antenna  or even a cut down dongle antenna placed  on a ground plane but mounted  as high as possible and away from obstructions  if  due to location problems you need to mount the antenna some distance away from the raspberry/pc its best to feed the raspberry pi / pc with a high quality usb cable from the dongle   rather than risk losing the signal in a lossy co-ax cable between antenna and dongle an over long  co-ax cable  will introduce  un-acceptable signal loss  the diagram to the right shows how to mount the dongle next to the antenna and keep it away from the weather  - an ideal container is something that once held salt/spice or such you can get usb cable up to 20m or more - they will have a 'booster' in line so you will need to plug it into a hub at the raspberry end otherwise you may see something like  cb transfer status: 1, cancelling which is caused when the dongle does not get enough power for the cables check the  fruugo site - french / english   aliexpress also sells them - french or go to the international site

 

 

1090 MHZ QUAD ANTENAE

 

CLICK HERE TO GO TO THE AUTHORS ORIGINAL PAGE 

I made this ant using some 14 swg copper enamelled wire and used a piece of aluminium for the reflector - it will work without the reflector - maybe desirable in some instances

 

 

A FILTER FOR 1090 MHZ

 

This filter may help if you have break-through / interference from a nearby transmission - there will be a slight insertion loss - it must be tuned exactly to 1090 MHz - otherwise you will have an un-acceptable insertion loss

 

 

DIPOLE LENGTH CALCULATOR

So you want to make a dipole for the 14 MHz (20 metres) ham radio band?

example - 466 / 14.025 MHz = 33.226 feet - so a 14 MHz ham radio band dipole has a total length of 33 feet - each leg is 33/2 = 16.6 feet

 

There are two local oscillators in most lnb's, switched with a 22 khz tone - without the tone a 'universal' lnb will default to the 9.75 g/hz lo -  giving a range of  10.7 - 11.7 g/hz - the 22 khz tone should allow it to receive in the 11.7 - 12.75 g/hz range  ( using either 12/18 volt supply )  18 volt supply will also change the polarisation. i have not tried yet to super impose a 22 khz one onto the line as 10.7 - 11.7 g/hz is sufficient range for the 10 g/hz band i am still experimenting with things

* please check your specfic lnb to confirm maximum voltages and frequecy range etc *

                                                                   

 Note the transmissions are RHCP but using the dish above will reverse the polarisation so you must wind the helix so it is LHCP

see the authors site for calculating the  dimensions for the helix antenna - a good site for various things

jaero authors site

 back to my jaero page

 

 

INCREASING WI-FI SIGNAL & RANGE

Extending your Wi-Fi range if you have your ads-b receiving station set up some distance from your house i.e. in your garage or garden shed

if its mounted outside you will have to weather proof it somehow