Just bought a used Jetvision antenna SCO-1090-GPS for €25, unfortunately this antenna suffers from a know issue, broken seal.
Does any one here ever tried to fully dissemblable this antenna?
It looks like the lower metal part is made of two pieces, I will try to disable it and try to clean it.
It looks that the antenna is worst shape than expected, all the capacitors are corroded and I could not get their values.
Since I have no plans to use the GPS probably I will bypass all the capacitors.
Did you purchase that antenna, or was it part of a FlightFeeder kit?
I bought it used and was aware of the possible problem with this antenna.
Ah, ok. Thanks for the reply.
buy yourself some electrical contact cleaner and go at it with a tooth brush, that will remove the green and most of the corrosion.
If any pcb track has gone replace the track with some tinned copper wire. Remove any corroded solder with some solder wick or a solder sucker ,and reflow the joint.
Should be fine after that. Have repaired way worse than that before.
After taking close look at the antenna I came to the conclusion that this antenna is made with two modules, the GPS and the 1090MHz antenna.
They are soldered together (this picture was taken after separating the parts)
The 1090MHz antenna contacts are compatible with the metal connector. Since all the capacitors are gone and I could not find their value, I will remove the GPS module (I wasn’t planning to use it) and solder the antenna to the connector.
If anyone is interested to see the antenna, here is a picture, it’s possible to see the 2nd layer and a via that connects both layers.
If anyone needs more pictures or measurements from the antenna please leave a comment.
That’s what I’ve done but unfortunately all the capacitors were corroded.
If you have any caps around att all its worth a punt fitting something, my guess would be low pF values.
Using WD40 Contact Cleaner I did managed to clean everything without desoldering the board. The lower capacitors I have are around 60pF so I solder a wire and it’s working.
In the following days I’m planing to put the antenna outside to check the results, probably will also test with the capacitors in place before closing the antenna.
I wonder if the antenna was manufactured and tuned assuming the GPS antenna was connected. Probably was. It’d be interesting to see what the ADS-B stats are like both with that pigtail connected and without it.
Assuming the PCB trace parallel with with each C1, C2 behaves as an inductor, each pair will behave as a Band Stop Filter (Parallel LC) (infinite impedance) to the frequency on the other port.
If this is the case, the GPS antenna will “not exist” to anything happening at 1090MHz.
My inicial plan was to replace the capacitor. I emailed the antenna manufactor asking for the capacitor values but they couldn’t help.
I’m hopping that even without the capacitors this antenna will outperform my current one.
Leaving out the cap will degrade the performance of the GPS antenna, but shouldn’t effect 1090MHz.
I use those PCB antennas as a base line reference. Anything I build, change the filter, amp etc. is compared back to a repeatable reference.
Finished the tests with the Jetvision antenna without capacitors.
Bellow you can see some results from the “Performance Graphs” and a comparison of the “Flightaware” statistics with the nearest 3 sites.
I believe that the Jetvision antenna is performing worst than it should, I don’t have tools to confirm it, but I’m happy that it performs better than my previous PCB antenna.
I was looking at the original capacitors and I think I can reuse the C2, I believe the C3 is there to block DC since there is a short in this antenna I will leave a shunt in it’s place.
I would rather say your expectations are higher than they should