Elecraft KIO2 User Manual
K i o 2, Assembly and operating instructions
Elecraft • www.elecraft.com • 831-763-4211
E
L E C R A F T
K I O 2
A U X I / O M O D U L E
Assembly and Operating Instructions
Revision C, June 6, 2012. Copyright © 2012, Elecraft; All Rights Reserved
Introduction
The KIO2 option allows the K2 to be remote-controlled by a computer. It also provides a number of useful
signals for interfacing the K2 to other equipment. With the KIO2 option and a small lap-top computer, the
K2 becomes a highly integrated field contesting or DXpedition station.
Many transceivers with serial interfaces provide only logic-level (TTL) signals, so that connection to a
computer requires an external RS-232 converter. In contrast, the KIO2 provides true RS-232 signal levels.
It also adds very little to the K2's receive-mode current drain.
RS-232 interfaces are often significant sources of RFI (radio frequency interference), which can degrade
receiver performance. This is because most RS-232 driver circuits use a 20-200 kHz square-wave RC
oscillator to generate the negative DC voltage needed for signal drivers. To minimize RFI, the KIO2's serial
interface provides an HF crystal oscillator (operating well outside of any ham band) to generate the
negative driver voltage.
In addition to the serial interface, the KIO2 includes an AuxBus output and +12 VDC for use with small
external accessories, as well as signals for controlling an external power amplifier. All signals are RF-
filtered. Shielded cable and all connectors needed for connection to the computer are provided in the kit.
Specifications
RS-232 Interface
Data Rate and format
4800 baud, 8 data bits, no parity, 2 stop bits
Handshaking
None
ESD protection
+/- 15 kV; signal lines RF filtered and shielded
Current Drain
5 to 10 mA (typ.)
Size (KIO2 PC board)
1.5" (L) x 1.5" (D) x 0.5" (H) (3.8 x 3.8 x 12 cm)
i
Caution: Some components in this kit can be damaged by static discharge. Before handling any
transistors or integrated circuits, always put on an anti-static wrist strap or touch any grounded, unpainted
metal surface.