Adding a CTCSS encoder to a Kenwood TW4000A

[AB3OL]

    Have a TW4000A dual band 2M.70cm transceiver without a CTCSS tone encoder. Where and how do I add a CTCSS encoder like a Comm Specialist TE-12P encoder so that it will work on both the VHF and UHF bands?

[KA4POL]

I guess you got a schematic. This shows a tone unit which is hooked up to the Mic Gain potentiometer. You need to connect to the same spot. Make sure there is a capacitor to block DC.

[W9GB]

The original dual band CTCSS for this radio was the Kenwood TU-4C option,
which were 2 encoders stacked on top of each other.
It does not appear that Piexx makes a direct replacement (you can ask them).
http://www.piexx.com/index.php?main_page=index&cPath=6

Kenwood TW-4000a - Universal Radio listing of accessories
http://www.universal-radio.com/CAtal...s/tw4000a.html

The current internal Com-Spec model is the: SS-64
http://www.com-spec.com/insheet/ss64inst.pdf
The TE-32 is the SS-64 encoder in an external PacTec enclosure with a tone selection knob.

It appears that you would need 2, or ability to inject CTCSS at a common point (schematic needed) in order to emulate the Kenwood TU-4C option.
Communication Specialists never wrote a specific application note for the TW-4000a.

[KB0NND]

Lucky you!

I have a tw-4000a, and a CommSpec TE-32 I got directly from CS. I traded out the original TU-4C CTCSS encoder for an antenna locally, and installed the TE-32 as follows (the gent who sold it to me included instructions for connecting directly to the tw-4000a):

From the TE-32
orange and grey, not connected to the radio.
wire shield, not connected, wrap it out of the way.
black, red, white are used.

in the radio (bottom, same side as power input) find a 4-connector plug for the optional TU-4C.
Wire colors you're interested in are:
orange/white [V+]
orange wrapped (has black [gnd] and white [pin 1 sub tone unit])

connect like this:
radio white to TE white (tone out)
radio black to TE black (gnd)
radio orange/white to TE red (V+)

I cobble up a set of pins to fit into the plug as I more the units occasionally. Works FB!

Have fun with a fabulous radio!