Elecraft KIO2 User Manual

Page 18

Computer Control Using the KIO2

Computer, Antenna, and Noise Considerations

Desktop computers and their peripherals--especially monitors and networking equipment--can generate
spurious signals over wide portions of the HF spectrum. If your antenna is fed with coax, you may not hear
any computer-generated noise at all. However, if you use an end-fed random-wire antenna that's connected
directly to the transceiver, or use unshielded feedline (twin-lead, ladder line, etc.) you'll almost surely hear
birdies or hash on some bands when the computer is on. Even if the computer is not being used for
communication with the K2, its RFI may be heard on quiet bands.

If computer-generated noise is a problem at your QTH, you may have to improve your ground system, re-
orient your antenna(s), move the antenna(s) farther away, or use coax feed. When you're only using the
computer to control the transceiver, you may be able to turn off networking equipment and switching
power supplies, which are the worst offenders.

Some types of weak, computer-modulated noise heard on quiet bands can be reduced in amplitude by
disabling the KIO2's on-board crystal oscillator. The negative supply voltage is then derived from the
computer's "RxD" signal. This alternative is described in the Troubleshooting section.

Software Configuration

The KIO2 is intended to be compatible with a wide range of existing PC-based logging, DXing, remote
control, and contesting applications. However, we cannot guarantee 100% compatibility. Some applications
have been (or will be) modified by their developers to take advantage of the K2's full command set.

In general, software used with the K2 should be set up as follows:

Radio Type:

Elecraft K2

Interface:

4800 baud, 8 data bits, no parity, 2 stop bits (1 stop bit will also work)

Handshaking: Set to "None" if this choice is provided. No hardware handshaking is required.
Polling:

Many programs periodically poll the radio to see if the operator has manually

adjusted any of the controls. The K2 can respond very quickly to these requests, but

we recommend a setting of 1-3 seconds to minimize possible computer noise.

TX Polling:

Polling during transmit is allowed, but we recommend turning it off.

Table 1 (page 19) may provide further details about using your software with the K2. Check our web site
for more up-to-date information. Also available on the web is the Elecraft KIO2 Programmer's Reference,
which you can consult when writing your own K2 control programs.

If your software does not list the K2, select the TS-570D or the closest equivalent (950, 850, 50). The K2 can

recognize a large subset of TS-570 commands. (TS-570 is a trademark of the Kenwood Corporation.)