Computing In The Shack - G7SYW's amateur radio bits & bobs...
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Computing In The Shack

| Posted in Digi-modes, Technical Topics, The Shacks


Until fairly recently, I used MixW for digimodes and logging. Due to it’s ease of use, configuration and the extremely flexible macro capability of the software and very low use of computer resources make it ideal for using with older hardware.

For data modes, radio control and logging I currently use the last free version of Ham Radio Deluxe v5.24.38 (HRD) software suite.

The main programs in the suite are computer radio control (CAT), logbook & digital modes software (DM780).

The HRD logbook has the ability to use a MySQL database. I use this method to keep my online logbook instantly up to date.

It also allows the log to keep a wide variety of information compared to the MixW log, which is one of the reasons I switched from MixW to HRD.

The only feature that I miss from MixW is the ability to easily print QSL cards on a custom layout.
To overcome this, I have written my own QSL printing program which takes the information I need from the MySQL database to print on my QSL cards.

At some point in the future I may develop the program further and release it to enable other HRD users to print their own cards directly from their logs.

The latest commercial version of HRD has the ability to print QSL labels but this feature isn’t customisable enough for my needs.

CAT Control

CAT control of the radio consists of a cable connected to either a USB port or COM port on the host computer and to a dedicated port on the radio.

Most modern radios now feature a USB port to support CAT control and soundcard interfacing using a single cable.

The computer and radio communicate with each other and the software displays the radio status on screen and sends commands to the radio allowing the operator to change the frequency, alternate between transmit and receive, access the radio memories etc.

Radio audio interface

To connect the PC to the transceiver I currently use a Signalink manufactured by Tigertronics which
also incorporates a built in soundcard and connects to the computer by USB.

Isolated PC to Radio Interface
In the past I used to use a home made isolation interface, download a copy of this schematic here.

This interface ensures that there is no physical electrical connection between the PC and transceiver to eliminate ground loops and minimise RFI problems.
It consists of two 1:1 audio isolation transformers for the audio and an opto-isolator for receive/transmit switching.

I had HRD configured to use the serial port in the PC (hardware, not USB adapter) RTS signal to switch the transceiver to transmit when using digital modes, and the DTR signal for CW (morse) keying, the CAT control was (and still is) via a separate USB adapter designed and built for use with the Kenwood transceiver.

The Kenwood allows the use of an external keyer, in this case my PC, or the internal keyer for use with
a paddle by means of a switch on the back of the radio.

Having the switch on the rear of the radio is hardly convenient but I imagine it was designed to be set and left.

To overcome the problem of reaching around the back to fiddle with the switch a modification can be found online to allow either to be used.