Mk182 digital echo mic beacon

I have been trying to get this to work for some time!
The first problem was the pads and traces falling off and also shorting out (as if built for a ghz circuit).I solved this by using an extremely low soldering temp.
I once purchased the repeater controller by Radio Tone around 2018 for use on a Midland lxt-118 with compatible motorola plug supplied by Radio Tone.
The lxt-118 does not have a touch dtmf pad so I used a remote tt to turn off roger beep, remote off etc.none of these worked.
I realize now it was probably the anti vox (no adjustment or schelmatic) I sent it back.
after several years I was able to get the digital echo to work
but could not get a (single) cb echo effect.
The problem was that there appears to be an anti-vox in the circuit that does not allow transmit or a quick key reply, and there is no adjustment (not mod).
So what I need is an exact replacement of the HT8972/B80500048G chip with a modification to allow triggering the internal digital stream of around 500ms with full intellegibillity as the sound of the echo is very distorted when changing (R2?)delay.