(tr)uSDX only giving 0.8W on 12V

[S54OM]

Hello,

so we bought a few (tr)sdx kits from an official seller. Now we have a problem that a some of them are only giving out 0.8W tx with 12V input power via jack and some are working perfectly. Updating FW did not help. We did some testing with working/not working boards and found out that the problem is located on the main bard (switching boards betwen working and not working). Is there any common solution for this? It seems like it doesn't switch from 5V to 12V configuration (0.8W on 5V is normal).

Thanks in advance
73 de S54OM

[SP9TKW]

Check soldering of SWR bridge - two FT50-43 cores next to SMA socket. That is the most common cause for it. Make sure that wires are scraped well from enamel.

What is your SWR reading on the screen? Most likely 9.99.

GL Marek

[S54OM]

Thanks for the advice, I checked everything twice and resoldered every contact, cleaned the board, but the problem stays the same. Im getting an SWR reading of 1.04 to 1.1 and have no problem transmitting and receiving and made a few local QSOs.
I measured the output with a HP spectrum analyser and the readings are the same. When I switch my RF board to an other (working) main board it is working perfectly giving out good 4W. Then I switch my main board to a (working) RF board the problems occurs again, giving out .08W.
So the conclusion is the RF board is good and the main board has a problem.

73 de S54OM

[LILO]

I would check DRIVE signal pin 12 first mcu->driver->output fet

Also +12V coming from main to rf board and to the amp transistors.

[S54OM]

Thanks for all the advice, there is no problem anymore.
The story came to an end today while re-working and doing measurments, I accidently coused a short circuit, which coused to burn everything what it is to burn. So better luck next time.

73