[Kenwood] 940S Transverter Connection

Fri, 11 Jan 2002 14:40:51 -0600

Here's something I researched and wrote up many years ago.  I hope it helps

KENWOOD FROM THE BACKSIDE

Tony Appelget,  KoDCF

Although any modern HF transceiver is a marvel of completeness in one box, I have had occasion to want to use other devices in conjunction with my TS940.  Supposedly, nothing should be easier since there are connectors on the back of the transceiver and an explanation in the owner's manual that tell how to do such things.  HAW!  I found that Kenwood had apparently planned that only their units would be conveniently connected using their cables.  That being the case, they expended no great efforts to explain the rear panel connections for external devices.  I have had to do a lot of digging in the schematics to determine what happens at the various pins on the various sockets.  Maybe what I learned will help you.  Only you can be the judge of that.

The two connectors that I am about to describe are the REMOTE and X.VERTER.  They are 7 pin and 8 pin DINs respectively.  As far as I am concerned, they are wretched connectors.  They are too small for the number of wires to be connected to them, the pin numbering is not sequential around the connector, and they are a bear to get the shell installed on.  Another minus for Kenwood.  But that is not the subject of this writing.

I am not going to supply a picture of the connections, since you already have one in your owner's manual.  Based on what I learned while researching what I needed, I am going to supply you with a better explanation of the connections than the owner's manual gives you.  Use at your own peril.  `Nuff said for preliminaries.  

X.VERTER connector:

Pin 1.	Ground.  Goes with pin 7.

Pin 2.	+12V ON transmit, max. 50 mA.  I had no need for this, so I can't comment further.

Pin 3.	RX coaxial earth.  Goes with pins 5 and 8.

Pin 4.	To transverter ON-OFF switch.  Grounding this pin disables the power amp stages in the transceiver and connects low-level transmit signal to pin 7.

Pin 5.	Transverter RX signal. Connects to the receiver section of the transceiver.

Pin 6.	External ALC input.  Might help keep the modulation clean if the external device supplies ALC back to the transceiver.

Pin 7.	RF output.  Low level transmit signal out.  I have no idea what the signal level is, however.  It seems to drive a Yaesu FTV-650 transverter allright.

Pin 8.	HF receiving antenna.  This pin connects to the main antenna jack through the antenna changeover relay.  Pins 5 and 8 are normally connected together through a switch on the back of the socket.  The switch is opened when a plug is inserted into the socket.  Depending on your needs, you may need to connect pins 5 and 8 on the plug.

REMOTE connector:

I didn't do as much research on this connector since it did not appear to have as many of the functions that I needed.  It appears to provide duplication of several functions found elsewhere on the transceiver.  Pin 4 was of the most interest to me.  On transmit, pin 4 is grounded, and capable of placing other cooperating devices in transmit mode.

---------- Original Message ----------------------------------
From: "W Halse" <[email protected]>
Reply-To: [email protected]
Date: Thu, 10 Jan 2002 20:53:29 -0600

>I would like to obtain information on connecting the 940 to a transverter
>such as a DownEast Microwave unit.
>The connection diagram in the 940 manual is not very helpful.  Does the 940
>require a special plug? Any tips on connecting the 940 to the transverter?
>Any operating tips?
>
>Thanks
>
>Bill, N9CDX
>
>- - -
>
>Your moderator for this list is:
>Larry Wilson KE1HZ [email protected]
>
>_______________________________________________
>Kenwood mailing list
>[email protected]
>http://mailman.qth.net/mailman/listinfo/kenwood
>