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Dear Pavel,
Thanks for the answer. Changed the hardware and using now PTT Out. Problems are solved.
Best Regards,
Gert PE0MGB

Hallo Marc,

I'm running Alex 0x21. The LPF and HPF are working fine, accept P07 T/ R signal on PTT IN. Pin 11 of the PCA9555.

Regards,

Gert PE0MGB

I have build an interface with the PCA9555 to controle my low pass filters. Filter switching is working fine.
I have one problem I also want to use the T/R relay (P07 disable T/R relay (0 = enable, 1 = disable) this is pin 11 on PCA9555
This is not working for me. Pin is not moving when I give a ...

Pavel,
You describe the pins to control the TPIC6B595 as follow:

The ALEX module can be connected to the pins DIO4_N (Serial Data), DIO5_N (Clock), DIO6_N (RX Board Load Strobe) and DIO7_N (TX Board Load Strobe) of the extension connector E1.

The DIOx_N are inputs. I think we need the DIOx_P pins ...

Hello Pavel,

Thanks, I will follow your suggestion with the TPIC6B595.

Best Regards,
Gert PE0MGB

Hallo Peter dc2pd,

Is the little pcb for the PCA9555 for sale ?

Regards,

Gert pe0mgb

Of course I measured the output. About -55dB with 100 watt output.

73, Gert PE0MGB

Hallo Markus,

You're right. For the Lima there were no doubts about a bandpass filter for TX. The 2nd and 3rd harmonic had about the same level as the source signal.
The cleanness of the produced spectrum of the Red Pitaya is much better. I measured about -45dB for the 2nd harmonic. A bandpass ...

Hello,
I have build a Lima-SDR together with DJ0ABR's bandpass filters, the lowpass filters and the 10 watt amplifier.
Recently I have replaced the Lima-SDR RX/TX by a Red Pitaya. The Red PItaya works fine with the filters and the amplifier.
Of course you need something between the 50 ohm filters ...