On 9/4/21 6:45 PM, Craig Leres wrote:
Something I can try without much effort is to swap in my spare SIM5380 modem, that might reveal some other issue with my setup.
I tried this and the sim5380 was able to register right away and I could see that it was active on the hologram.io dashboard. So I'm sure now that my antenna works at least to the u.fl pigtail. I checked resistance between the center pin of the ant3 u.fl socket and the pin on sim5380 module and it was single digits M ohms. But I see now that both ant2 and ant3 on my sim7600 module are shorted to ground. So that's a problem. I remember trying to move the u.fl socket from ant3 to ant2 and giving up and soldering new sockets in both locations. And I found the socket I removed. Comparing it to some unused new sockets (mouser 712-CONUFL001-SMD) I see they this stupid tab that comes off of the grounded part of the connector. I thought all 4 sides of the old u.fl were soldered but looking at the old one I removed, I see now that only 3 were and the 4th just had solder on the trace. Oops. Well this should be an easy fix (assuming I haven't hurt the simcom -- but if so I have two new sim7600 and one sim7100 handy). Craig
