So you have decided to run a digital mode or two plus CAT control you transceiver. The chances are that you don't have enough serial ports (particulary if you have a brand new laptop that has no serial ports at all).

So you check on Ebay and purchase a few USB to RS232 adapters and a USB port - what are the issues?

These adapters (or at least wise all the ones I have purchased) do not produce the correct RS232 voltages i.e. instead of +12V. -12V and 0V they poduce +5V, -5V and 0V. Every CAT enabled transceiver plus virtually every other piece of equipment I have tried works happily with the 5V RS232. The only exception todate is a Vellman PIC programmer.

The other issue is that every time you move the USB adapter to a different USB socket it changes the assigned COM port. To overcome this issue I recommend that you keep the same adapter plugged into the same socket be it on a hub or on the computer itself. Same goes for the hub - plug it into the same computer USB socket every time it is connected. Obviously label the hub and the adapters to make it possible to disconnect all the USB adpaters and put them back in the same position.

Some software can cope with the full range of 255 COM ports whilst some others can only handle 4. Because of the latter you may need to allocate a specific COM port to a USB adapter. These next steps should help you achieve this:

1. From the Control Panel select SYSTEM
2. From the SYSTEM window select the hardware tab then press the "Device Manager" button.
3. From the "Device Manager" window expand the PORTS section.
4. You should see you USB RS232 adapters listed.
5. To identify a given adpater try pulling it out and re-inserting it. The window will dynmically update as it initialises the device.
6. Once you have decided which USB adapter is which then you may need to select a different COM port for it.
7. On the appropriate adapter use the right-hand mouse button  to select properties.
8. From the properties window select the "Port Settings" tab then press the advanced button.
9. The advanced settings winows has a COM port selection facility.
10. Once you have this set up then label both the adapter and the hub so that a given adapter can be replaced in the same socket within the USB hub.

Hope you find this guide helpful - don't forget to provide feedback.

John - G8IOK