Cable for Kenwood TM-732A

1

What cable for Kenwood 732A?
Thanks in advance!
Jorge

2

At this time there is no pre-made cable in store so this will have to be a homebrew build.

Because the radio has no accessory port we’ll need to get signals elsewhere. Luckily, according to what I can find online, the mic connector also has receive audio which simplifies our build.

image

The pinout would look like this:

RJ-45 pin 2 (RD) → 3.5mm TRRS tip (RIG_AFOUT)
RJ-45 pin 3 (MIC) → 3.5mm TRRS ring 1 (RIG_AFIN)
RJ-45 pin 5 (PTT) → 3.5mm TRRS ring 2 (PTT)
RJ-45 pins 4, 6 (GND) → 3.5mm TRRS sleeve (GND)

Please report the results if you end up building this cable.

3

Thanks Denis for your reply!
I’ll build it and report back to the forum!
Jorge

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4

Hey Jorge:

Did you ever build this cable? Did it work?

I have a 732a that’d I would like to connect. Where did you procure the phono adapter for the DigiRig? And, I, not sure which pins go to which connectors on the phono adapter.

73’s,

Eric - NOJVP

5

Hi Eric! In Denis replay is the key.
“RJ-45 pin 2 (RD) → 3.5mm TRRS tip (RIG_AFOUT)
RJ-45 pin 3 (MIC) → 3.5mm TRRS ring 1 (RIG_AFIN)
RJ-45 pin 5 (PTT) → 3.5mm TRRS ring 2 (PTT)
RJ-45 pins 4, 6 (GND) → 3.5mm TRRS sleeve (GND)”

You can fine the phone adapter in Amazon or for that mater even in a dollar store.
The adapter or cable has to be 3.5mm and TRRS.
TRRS means the adapter has a Tip-Ring-Ring-Sleave. Regular audio adapters/cables only has TRS (Tip-Ring-Sleave) only one ring.
Hope this help!

Jorge VE3EAD

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6

Jorge:

Thanks. That is super helpful. Maybe I will attempt it with some twisted pair CAT 5/6 cable. Did you have any luck? Or, did you pass on the project?

The Denis diagram. I assume, it looking at the radio and the female port into which the Cat 5 plug is inserted.

Thanks.

Eric
N0JVP

7

Follow the numbers on the RJ-45 connector.
On Denis diagram Pin 1 is show as DWN and Pin 8 as UP.
I not make my cable yet cause some health issues, but I will do it in the near future!
Good luck!

Jorge VE3EAD

8

Thought I’d post an update. I built this cable today per the instructions provided above. I plugged it into my new Digirig and my old Kenwood TM-732a. And . . It worked!

I was able to sync up to and communicate with an almost nearby (32 miles away) VARA FM WinLink RMS. Connections were successful.

Since it is an old radio (and some distance to the RMS station) I’m limited to 1200 baud (actual throughput today was about 750 bps).

But, as far as the cable goes, everything tuned and keyed up as advertised.

Thanks for the posts and the help.

Eric
N0JVP

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9

I’m happy for your results Eric! I’m still have to build mine but your build encourages me.
Thanks
Jorge VE3EAD

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