Subject: CIRCUIT MODIFICATION FOR KENWOOD TR7930/7950 TRANSCEIVER

              FOR PACKET/RTTY OPERATION

                      BY:WA4IXN



this modification provides controlable audio output

to pin 5 of the mic connector for single plug packet/

rtty operation.



remove top cover of transceiver and carefully disconnect

speaker lead plug from "rx unit" board.

locate plugs"j-13" on the right front of the "rx unit"

board and "j-18" on the left rear side of the board.

notice which wire goes to pin "8-m" on "j-13" and to pin #5

on the mic connector.

remove plug "j-13" from the board and locate the spring

tab on the side of the plug that holds the "8-m" conn-

ector in place.

using a small awl or pointed tool, press the tab down

and carefully pull the "8-m" connector from the plug.

work the wire from the harness so it will reach back

along the left side of the board to plug "j-18".

using the awl or small pointed tool, carefully spread

the "8-m" connector a slight amount so it can be fitted

like a sleeve over another connector of the same size.

locate terminal "ap" on plug "j-18".

continued in file tr7930.1

tr7930.1



insert the spread terminal "8-m" into the top of plug

"j-18" so it fits around the top of terminal "ap".this is

a fairly tight fit, so  use care not to bend

the terminals by using too much pressure.

about half of terminal "8-m" will stick up above

the top of terminal "ap".  the lower part will be

firmly sleeved around terminal "ap" inside the plug.

dress the wire around the left side of the board.

replace speaker plug and install top cover.

plug tnc cable with ptt/audio in/audio out/ground connectons

into mic connector and it's ready to go on packet/rtty.

no soldering is required and unit can be returned to

original state at any time if necessary.

the end!                        relayed   by...n0kgx...gene