K1EL K45 CW Keyboard and Reader Manual K45B
K45 User’s Manual – Rev B.0
3/8/2023
Page 31
Appendix B - K45 Modem Quick Start
Interconnection Diagram
The following diagram illustrates a K45 set up. A CW paddle is optional and not a requirement. A PTT
connection would not be required for normal CW keying of a transmitter or transceiver, the PTT output is
used primarily in RTTY mode, HSCW mode, or to key an amplifier or antenna relay. The keying output of the
K45 is capable of keying virtually any solid state or grid block vacuum tube transmitter and is optically
isolated from the K45 chassis for safety.
Gnd
Iambic
Paddle
USB
Host I/F
(power)
Dah
Host
Keying
Output
Keyboard
Audio
Input
Paddle
Input
Gnd
PTT
Ke y
Audio
Input
N/C
Ke y Line
to XCVR
K45 Back Panel
Dit
AF
USB
Ke yboard
Gnd
Figure 31 - K45 CW Keyboard Hookup Diagram
Which Keyboard to Use
The K45 will accept just about any wired or wireless USB keyboard. Surprisingly, most wireless USB
dongles draw significantly more current that a standard wired keyboard. This may be a consideration for
portable battery operations. The keyboard can be plugged or unplugged while the K45 is powered on.
Power Supply
The K45 is powered through the USB host connector. This means it can be powered by connecting it to a
host PC, a USB charger, or battery pack. The current draw of the K45 is low, about 120-150 mA so even a
small USB charger will work fine. Use a good quality USB charger, one with good voltage regulation.
Power On/Off
The K45 will power up as soon as it is plugged into a USB power source. It can be put into a low power
standby mode by the
ESC-O
command or by holding the encoder button down for 3 seconds after the
configuration menu appears. In standby mode, the display backlight is turned off and other electronics set to
a low power state. To wake the K45 up, simply turn the encoder one or two clicks.
Internal Sidetone Speaker
The sidetone speaker on the K45 provides audio feedback as Morse is transmitted. There are four sidetone
volume levels that can be set via Configuration Menu #3:
STvolume
. In most setups, the K45’s sidetone
would be turned off and a transceiver’s sidetone used instead. However, the K45’s sidetone speaker is
useful for code practice or testing purposes. Please note that the internal speaker can’t be used for receiver
audio. (This was a common question from K42 and K44 owners)
Transmitter Connection
This is highly transmitter/transceiver dependent. It can be as simple as making up a cable with an 1/8-inch
mono jack on each side or as complicated as using stereo jacks and modifying the keying mode in your
transceiver’s setup menu. Here are the basics: Figure 31 above shows which pins on the stereo output plug
do what, your job is to check your radio’s manual and determine what the cable/connector wiring should be.
In general, the key line is the tip of the phone jack and the transceiver needs to be configured such that its