I have a cheap antenna bought from Amazon that sometimes performs really well and then very poorly. Seems to be when the cable is moved about, but I don’t think it is a bad connector. Sometimes just touching the cable will cause the messages per second to go up, and letting go causes it to go down.
I have it mounted inside on a window mullion and it is connected to the Pro Stick Plus and connected to a RPi Zero W.
Is there a trick to getting better reception that I don’t know? Could there be an impedance problem? Is a better antenna recommended?
What is the window mullion made of? Plastic, aluminum, steel? That type of antenna needs a ground plane under it. A metal can, metal cookie can lid, a steel pie plate works also. If the mullion is plastic or aluminum, then any scrap piece of sheet metal (preferred) would work. Those antennas are notoriously bad to start with, so shop around for something better. A homemade “spider” antenna works well also.
You say you have mounted it on the window mullion, that is the vertical beam.
Does this mean the antenna is mounted horizontally?
Can you post a picture of your antenna installation?
The window is a large aluminum storefront type (I am on the fourth floor). I experimented with the antenna on the middle mullion, about 3 feet off the ground, in a couple of locations, but the best place I have found is on the bottom mullion at the floor and near the corner as in the photo. I am using a square of hook and loop to fasten it down. Currently I am getting 50-125 messages per second (seems to hover around 80 most of the time). The window faces NE towards PIE, TPA, MCO, and a bunch of others within 100 NM, but generally I get only about 50 NM out (sometimes a little further).
Some kind of antenna with a suction cup mount bracket that I could attach to the window would be ideal…
You’re feeding interference from the SDR / pi directly into the antenna.
The coax should not be squished.
Place the antenna on an empty food can and further away from the RPi.
Or at least move the antenna further away from the RPi / SDR.
Aslo if you don’t want to use a food can, at least set it directly on the window sill instead of putting something in between?
The base is magnetic and meant to interface with a metal surface.
Together you get a so called quarter wave ground plane antenna.
Also the antenna likely isn’t optimized for ADS-B, often it helps to unscrew the whip and replace it with a short wire.
Place the antenna over an iron/steel food-can on floor besides the Window. The floor in photo seems to be only few inches below the window mullion, so if you use a tall enough food-can, it will keep the whip at window glass level.
The magnetic base of antenna will cling to the steel/iron food-can without the stuff you are currently using to hold the antenna in place on the aluminum mullion. That stuff may be the reason of poor grounding of antenna base.
Equally important to proper whip length is placing the magnetic base directly over a steel or iron food-can or plate. Electrically an aluminum plate will do, but as magnet will not cling to it, the whip will keep on falling frequently. Adding something non-metallic between base of antenna and aluminum will hamper grounding. Using a plate or can made of iron/steel will overcome this problem.
As others have indicated, adding a decent ground plane (tin can etc) will bring improvements.
Based on photo of antenna placement, I would suggest moving antenna further to the left so its not so close to the metal window frame. This current location has the antenna somewhat hidden from signals to the right side of the view.
And as others mentioned, moving the pi & SDR below and further away from the antenna will reduce interference.
If you see improvements with these few suggested tweaks, definatley consider that for the cost of a purpose built antenna from Flightaware + appropriate coax cable and possibly an adapter, greater range and higher message counts are easily attained ( …once you read about adjusting the gain setting “down” due to the much higher sensitivity of the Flightaware antenna ).
Your stated 4th floor location will certainly help with your ADS-B spotting.
Cheers!
Increase the distance to the TV …
Other than that cables that include ferrite cores might be better … not sure if there are any for HDMI.
Other than that i guess it’s trial and error.
Going to set a couple of goals to perhaps raise the bar a bit. First, get an enclosure for the Pi and the Prostick; more for aesthetics than anything else, but it might allow for a better mounting location. Wish I had a 3D printer (FlightAware ADS-B Pi Zero W Receiver Case by Rkimmell73 - Thingiverse) but a plastic box should do nicely. Doesn’t need to be watertight.
After that will be to build a coaxial collinear antenna in some PVC or other tubing, add some suction cups, and stick it to the window. A lot of people have provided tutorials for this, present company included, and I have a soldering iron, loads of coax, some electrical tape, and a little time.
And a side note, after looking at the stats. At my old place, when I was moving out, I disconnected all my computer stuff, but left the PiAware running for a couple of days, just strewn across the floor with the antenna in the window. Without all the electronics interfering, and no change to the antenna position, there was quite a spike!
Which country do you live in?
I can print you this enclosure if you want me to, no charge apart from postage, but I am in Australia, maybe someone who is closer can do the same?
but that’s good.
