The K45 has a great CW reader but one thing that slows most folks down is connecting audio from their receiver to the K45's audio input. K1EL recommends getting audio from the receiver's audio line output jack which, in most cases, is located on the back of the radio. Usually it's in a multi-pin DIN accessory connector, which is certainly not very convenient. The reason the line out works so well is that it is a high impedance output, which matches the K45 audio input, and it is unaffected by the radio's AF gain control. You can turn the AF gain control up and down and K45 copy is unaffected.
The next best option is to plug into the radio's external speaker jack. There are two problems with this, the first is that it is a low impedance output, usually 8 ohms. The second is as soon as you plug something into the external speaker jack the radio's internal speaker is muted. Our recommendation, up to now, has been is to make up a Y cable but that doesn't solve the impedance mismatch. To solve this once and for all, we designed an audio splitter kit which takes the place of a Y cable and also solves the impedance mismatch problem. Unfortunately it doesn't solve the gain changing issue but it's a good compromise.
The K45 Splitter board has three 1/8 inch jacks, one for either a radio's headphone/external speaker jack, one for headphones/exernal speaker, and one for the K45's audio input jack.
K45-Splitter Features
- 1/8 inch (3.5mm) audio input jack. Connect this to your radio's external speaker jack.
- 1/8 inch (3.5mm) speaker audio output jack. Connect this to your external speaker.
- 1/8 inch (3.5mm) Hi-Z audio output jack. Connect this to the K45's audio input jack.
- K45 audio is coupled through a low level impedance transformer.
- 4 - 16 ohm audio input, 4 - 16 ohm speaker output and 4.7K ohm output impedance to K45.
- High frequency noise filtering.
- Audio attenuator to prevent K45 audio overload.
- Negligible effect on external speaker volume or tone.
- All connectors on board, no flying leads or components.
- Assembled and ready to use
K45-Splitter
(includes 1/8" to 1/8" cable)
$19
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