These antenna are called strip line antenna. They can be very good or not so good depending on the construction.
The jetvision ADSB antenna is a good strip line antenna. I have also tried some from china with mixed results.
They will corrode in water and must be sealed. The good ones will be marketed as 5+ dBi gain.
I’m about to set up my PiAware ADS-B in my two story attic beneath a plywood/asphalt shingled roof using the 26 inch Flightaware antenna. Anyone have any experience with this type of setup?
Roof will block about 30% to 70% of the signal depending on what the roof is made of. A few people have reported 100-250km in range with inside roof antenna. Outside you might be look at 300km+ range.
My case exactly, but inside the garage, not as high as a second floor roof. Since Sunday, after loosening up the antenna connector, the distance has approached 300 km.
I have the 26in FlightAware antenna inside a tiled roof and get 500km+. The main problem I have is the attenuation through the brick gable ends causing holes in the polar plot. It would obviously be much improved if the antenna were in the clear outside, and I do intend to put it outside when I can, but it works much better than I expected inside the roof.
All connectors (except gold connectors) will form a small layer of corrosion. This very thin layer is quite bad for electrical signals. The act of loosing or tightening a connector will wear away the layer and create a good contact again.
I usually suggest people make the connector tight to prevent air and water from getting into the connector. Loosing connectors will corrode over time. This is actually one of the first things we suggest to people if they email support about a reduction in range. Take apart the connector and check for moisture inside the connector and then put it back together. This really works in a majority of cases.
Using gold connectors is the one way to prevent this problem but not many people will pay the difference. I usually only see gold connectors on audio equipment and on motherboard and expansion boards.
The cheaper way to prevent corrosion is to tighten the connector as much as possible and then use a tape and/or sealers made for coax cables. The tape is called “amalgamating tape”.
This is the rational I use to tighten up all connectors, but something else is at play with my setup. Could be the different dimensions between 50 and 75 Ohms? Broken/bad contacts? etc.
Performance now is fantastic, and yet, a thinner pin on a wider opening, with a loose connector, is working great.
There is absolutely no moisture anywhere.
The only sure thing is that I finally found the source of my problems. I’ll spend more time and money on the connectors.
As for the amalgamating tapes, I use it a lot on my hamradio antenna connections, but as I said before, this one is indoors. No water, humidity, moisture.
I use another one from 3M. I used to use Coax Seal, but it leaves lots of residues. If you still want to use it, wrap the connection with electrical tape first.
Any electrician that does work outdoors or underground, has in his tool belt, besides the normal electrical black tape, one rubber self-fusion. Here in US we use the 3M from Home Depot, Lowe’s, or any other electrical supply store.
Strange, that poor dude, it’s missing the left arm
The forum “interprets” that back slash and uses it. If you add two, then it looks like this:
