Well…. What I can tell you… working backwards towards the code, ?TX_BPF_SEL and RX_BPF_SEL, or GPA0 and GPA1 for U15 which is I2C address Hex 0x25 on WIRE2.? ?GPA0: HI = BPF In Circuit During TX, LO = Bypass. And GPA1: HI = BPF In Circuit During RX, LO = Bypass.?

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Now in the code (which I do not know but Al and Oliver do), Somewhere in the code is in this (I can’t focus tonight but will do it tomorrow):

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#define LPF_BOARD_MCP23017_ADDR 0x25

#define TXSTATE 1

#define RXSTATE 0

#define TXRX_PIN 22

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// GPIO2 is mapped to TX pin:

// HIGH means TX mode

// LOW means RX mode

pinMode(TXRX_PIN, OUTPUT);

TXRX_state = RXSTATE;

digitalWrite(TXRX_PIN, TXRX_state); ?// RX mode

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if (selection == "TXB"){

? ? Serial.println("Toggling TX BPF selection");

? ? ? GPA_state = GPA_state ^ 0b00000001;

? } if (selection == "RXB"){

? ? Serial.println("Toggling RX BPF selection");

? ? ? GPA_state = GPA_state ^ 0b00000010;

? }

? if (selection == "TX"){

? ? Serial.println("Selecting TX state");

? ? TXRX_state = TXSTATE;

? ? digitalWrite(TXRX_PIN, TXRX_state); ?// TX mode

? }

? if (selection == "RX"){

? ? Serial.println("Selecting RX state");

? ? TXRX_state = RXSTATE;

? ? digitalWrite(TXRX_PIN, TXRX_state); ?// RX mode

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Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ

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Owner - Operator

Big Signal Ranch – K9ZC

Staunton, Illinois

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Owner – Operator

Villa Grand Piton – J68HZ

Soufriere, St. Lucia W.I.

Rent it:

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Moderator: North American QRO Group at Groups.IO.

Moderator: Amateur Radio Builders Group at Groups.IO.

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email:? bill@...

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