Antenna Recomendations


#1

I recently purchased the RTL dongle, and i’m looking for a better alternative than their stock antenna that comes with the unit. I’m not so good with wires and building antennas, so I would love to purchase one that has already been assembled and put together. I’ve got an open budget. I would appreciate any recommendations.

Thanks,
Ryan


#2

Join the Yahoo Group for planeplotter and search the posts, files and links section.

groups.yahoo.com/neo/groups/planeplotter/info


#3

have a look at ebay item 291236768693
also at 191327060948 (this is the one I use)

do a minimum price bid on these, often there is no competition and if you lose the auction, there’ll be another tomorrow

you will need to arrange some sort of mounting pole to get the antenna above the top of your roof - your local TV aerial shop will be able to sell you a bracket or something (take a picture to show them)

The antenna will come with a connector on the bottom, the second says it’s got an N female, so it needs an N-Male on the end of a length of downlead … what length do you need?

The problem is, if it’s a long length you need a better quality cable - if it’s only maybe 5 yards / meters - RG6 will be OK to start with.

There are places on the net that will make you up a length of RG6 (or better) cable with an N-Male on the end. The other end of the cable will also need a plug - this will go into an ‘MCX Pigtail’ (look on ebay) to connect to the dongle - the actual typ of plug needs to match the pigtail. See what’s commonly available in your part of the world (I’d probably use an F-Connector or TV antenna plug)


#4

hey peter, good to see ya on this forum =p

i made a coaxial collinear with RG6 cable 75ohm. 50 feet of coaxial cost me about 10 bucks on monoprice.com. i also used a female/female connector and some twist-on coaxial heads. the usb dongle uses MCX and i had to scour the internets far and wide for a female coaxial/mcx connector (eventually found one on ebay). i think i ended up with 14 elements on the antenna. YMMV depending on build quality, distance from receiver etc.


#5

If you want to buy an antenna, this is a decent choice:
amazon.com/dp/B001JT1KEG/ref … CA54KGQH5C

I build an antenna or two back in college but nothing since. Two weeks ago I build 4 different antennas and tested them out. A ground plane, J-pole, whip, and coaxial collinear.

The best performing one of the bunch was the ground plane antenna (I get readings 200 miles+). It was also extremely easy to build. I just cut an old RG-6 cable into three pieces, 2 about 1ft long and 1 about 6 inches long. The shorter one I left the connector on. I then completely stripped the two longer wires so all that was left was the center copper wire and stripped the shorter one down to about one inch from the connector (leaving some shielding exposed). I then twisted the two longer wires around the shielding of the shorter wire so each of the longer wires made once complete turn around the shielding. I then aligned the two longer wires so they were at right angles from each other and then tacked them to the shielding of the shorter wire with the soldering iron. I then bent the 4 ends for the two longer down by 45 degrees, and snipped all wires to be 1/4 wavelength.

Here is a link of how to build some antennas.
rtl-sdr.com/adsb-aircraft-ra … h-rtl-sdr/

If you have no soldering iron, a coaxial collinear is a decent choice. It can be made with wire cutters and electrical tape. However, its putsy and the performance is marginally better than the rtl-sdr antenna.


#6

I built my own antenna that was optimized based on another design. You can see what I did and all the info here:
http://www.radarspotters.eu/forum/index.php?topic=6621.0
I have it mounted in the attic of my two story house (so the top of the antenna is about 26 feet. Here is a plot of my ongoing results:
http://bocafallsweather.com/GMavplot/

Pretty easy to make, some cable, coat hangers, BNC panel mount connector and teflon block I got at the hardware store. Some soldering is required but it is pretty easy.


#7

a simple dipole antenna made by pulling the centre from some coax - putting the centre vertically upwards, braid downwards (both trimmed to 68cm) feed coming out horizontally will give up to 200nm with a dongle as long as the down-lead isn’t too long if the antenna is mounted above the roof.

This can be quite dainty (almost un-noticeable) if ‘the residents committee’ don’t like stuf stuck on the roof.

Do ground the braid to prevent static charge building on the assembly.


#8

Hi, I had simple dipole antenna for couple of months. Today I upgraded it to PCB antenna - described here: f5ann.pagesperso-orange.fr/Anten … index.html
It was not very difficult to build.

My range increased from previous max. 50 nm to current max. 230 nm. I had about 2000 hits max per hour, now I have about 18000 hits per hour. These numbers are based on about two hours of operation, so it will probably increase with air traffic increases :slight_smile:
I also used good cables - MCX to RSMA pigtail (RG316 I suppose), 3m RSMA to N cable and the antenna on the top.


#9

If the dipole gives just 50nm - something is wrong, check all joints, down lead quality & length, adaptors, etc.


#10

Yes, the main reason of so poor performance was probably in cabling.


#11

Using the title of the topic for my question :slight_smile:

I have the antenna flightaware sent me. Does it matter a lot if my antenna is mounted next to the 42mm pole it is using in that direction?
It is about 5 cm away from the pole, from top to bottom. In that direction. I understand it won’t do any good, but to what extend? Now i get about 100NM. will that double if i manage to put my antenna above this obstacle?
Not sure since there is a building 200 meter away that is higher than mine…
But i want to do better than my 8th place in the ranking :slight_smile:) Could be possible if i can receive traffic above london :wink:


#12

I think we need a photograph to show what you have and a diagram to show what you are thinking of.

At one time I reached #28 in the ranking, now im around #36 … it’s so unfair that there are others where the geography allows them to see more planes LOL


#13

Got one of these on order as it looks rugged and should perform reasonably based on my amateur radio background without resorting to a Yagi.

http://www.ebay.com.au/itm/Antenna-5-8-great-coverage-ads-b-flightradar-24-1090mhz-high-gain-N-connector-/301356623012?pt=UK_Mobile_Phones_Communication_Radio_Antennas&hash=item462a4124a4

I may however use a Yagi to improve my coverage to the North with an additional Pi unit. This one from the same ebay seller looks to be of solid construction and if the 5/8 is of a reasonable standard once delivered to Aussie will go ahead and order one along with another 5/8 for a different project.

http://www.ebay.com.au/itm/Ads-b-adsb-antenna-dir-4-element-yagi-1090mhz-flightradar-24-bnc-connector-/301356631402?pt=UK_Mobile_Phones_Communication_Radio_Antennas&hash=item462a41456a


#14

Isn’t there a parameter on dump1090 to allow it to see ‘the second’ dongle - maybe run two instances of dump1090 (also use parameters to change the ports on the second) and combine the data using modesmixer??? (just throwing ideas)


#15

as in my previous post mentioned, does it matter that the antenna is that close to the pole? i can’t get it any higher on that pole since the weather station is blocking the top. Thanks go to the clouds for the contrast in this night pic :laughing: :laughing:
https://dl.dropboxusercontent.com/u/90516818/DSC05790a.JPG

difficult to get a plot, certainly in the evening since there are less planes. sbsplotter crashes frequently since i use FligtFeeder…
ranges get further but it gives an idea… the pole is to the west, ie left
https://dl.dropboxusercontent.com/u/90516818/sbs.png


#16

Reprinted with permission


David,

Please see the notes from Marco here:

satsignal.eu/raspberry-pi/du … -operation

He runs two Raspberry Pi cards.

Cheers,
David

SatSignal Software - Quality software written to your requirements
Web: satsignal.eu
Email: david-taylor@blueyonder.co.uk



#17

[quote=“PeterHR”]

Has anyone experienced the DPDproductions.com ADS-B Vertical Outdoor Base Antenna?
I am having a problem with the reception of position and aircraft reports with this antenna and I’m at a loss.
I have a NooElec TV28T v2 SDR & DVB-T USB dongle with the standard magnet antenna plugged into my Pi and I see more than three times the reports than the DPD antenna. DPD suggested that maybe the signal is overdriving the receiver. I typically receive 18K plus in position reports with the little magnetic antenna that is inside my building compared to the 6’ DPD antenna that is mounted on top of my building that is only seeing about 5K per day.

Any suggestions?


#18

[quote=“psellati”]

are you comparing both reports the same way? are both your own reception reports? or are both reports from flightaware? if not there can be a huge difference. Flightaware gives me 400-500k reports a day. i did check it with sbsplotter, as you can see above and got 131k positions in +30 minutes during the late evening, which means +2 million reports a day, a huge difference!


#19

I just modified my fadump1090.sh to set to autogain and enabled AGC (see Post subject: RTL Dongle Gain Question) What a huge difference, I have more than doubled my reception distance and I can only anticipate a major increase in traffic.


#20

Be careful about this - my RPi is quite loaded with only one dongle. I needed to run dump1090 quiet (which is also the default for fadump1090, so no issue) to keep load reasonable.
See my load figures. I get about 200,000 positions daily.
I needed to do some tuning on RPi to make it run well… I had another one stick in RPi which I wanted to use as radio receiver (Control Tower at LKPR etc.), but RPi does not have enough power to handle it anymore…

CPU load on my RPi last week:
http://imageshack.com/a/img910/7987/KLBKlO.png