Cable for Anytone AT-778UV

Like in case of many mobile transceivers we’ll need to gather required signals from multiple connectors:

The audio must come out of the headphone jack, though there is a bit of a gacha there.

The amp uses a bridge-tied load (BTL) design while Digirig expects unbalanced input against the ground.

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We can either:

  1. use an audio transformer from tip and sleeve on transceiver side to primary winding and from secondary winding to ground and RIG_AFOUT on Digirig side or
  2. just connect tip to RIG_AFOUT and leave sleeve unconnected on the transceiver side. This effectively halves the amplitude, but Digirig has enough sensitivity that this is not going to be an issue

So the final cable layout is like this:

RJ45 pin 1 (GND) → RJ45 pin 4 (MIC GND) - this may be not required and needs testing
RJ45 pin 1 (GND) → TRRS sleeve (GND)
RJ45 pin 2 (PTT) → TRRS ring 2 (PTT)
RJ45 pin 3 (MIC) → TRRS ring 1 (RIG_AFIN)
TRS tip (EXT SP1) → TRRS tip (RING_AFOUT)
TRS ring (EXT SP1) → NC
TRS sleeve (EXT SP2) → NC

Users-Manual-3731629.pdf (1.5 MB)

Are you using 2 TRRS plug or 1 and doubling up wire? I am hoping to adapt this to my BTECH UV-50X2.

Not sure if that’s your question, but you can use TRRS in place of TRS connector, just short unused ring to sleeve:

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