Re: [softrock40] TX Mixer (QSE) Pins 2 and 14
----- Original Message -----
Subject: [softrock40] TX Mixer (QSE) Pins 2 and 14
> I've completed up to the QSE stage and up to this point have not failed any tests. The RX was working great until after I built
> the first two transmit stages.
> After finishing the QSE stage I noticed I was getting 5v on pins 2 and 14 of U8. After a little googling with minimal results I
> tried to power up the board and see if the RX still worked, and it doesn't. I also can't hear the LO anymore.
> Also of note, I get the ??RX power down?? indication in CFGSR.
This means that U1 is not seeing U3.
Your U8 readings probably show that U3, the Si570 is not working.
It could be because there is no 3.3V. Trust your DMM, I do not think the 3.3v light can be used as a diagnostic. In any case it is
This sort of fault is usually a bad solder joint on the regulator or Si570.
73 Alan G4ZFQ
The 3.3v light is also red.
> Could I have roasted the 3.3v regulator with my DMM? I tested T2 and L1 in circuit.