How fix talkback in magnum delta force

You need to check the audio path from the chatback board to the audio circuit

usually the audio out the board will go to the center connection
on the volume control
sometimes people use a resistor to attenumate it to a level
or a T pad
and connect it to the left side {audio out to amp}
so a volume control works like this

left center right
ground audio into control audio to amp

so usually the center is used as the volume will track up as your sets volume is increased

so simply connect the audio out from the chatback
to the right audio to amp section

on the chatbacks ive made and installed in the past
had a small pot on the board
this allows the volume from it too be increased

so look for this first

if you cant find it you can make one up like this

100K log pot 3 pin

1 2 3
L M R {left middle right}

1= ground
2= audio from chatback
3= audio to the right right audio to amp on the cb's volume control

then no matter what level the actual audio from the set is set too
the chatback can be set to a standard level for all

hope this helps you

i used too build chatbacks for the rnid year back and fit them free