[Elecraft] Outboard speaker for KX3

[Doug Person via Elecraft]

I built an outboard amplifier/speaker especially for the KX3.  It 
consists of a pair of 2 watt 4 ohm 50mm speakers in a small plastic 
utility box.  The amplifier is a tiny (1.25" x 1.25") stereo class D 
board (with volume on/off control) I bought off ebay for about US$4.  
Including connectors, the whole project was less than US$10. The result 
is a very satisfactory, compact speaker/amplifier with room-filling 
audio output.  I've included an internal, rechargeable LiPo battery for 
portable ops. (Although, I'm more likely to use earbuds out-of-doors).  
The only negative, if you consider it one, is the low-end response cuts 
off somewhere around 300 hz - so not much bass.  But, for normal voice 
communications, it works splendidly.  The total size is roughly 2.5" x 
4.5" x 1.25".  The box is quit rigid and does not buzz or vibrate.  The 
power supply is a decent, regulated 5V 2 amp wall wart.  There are not 
any notable artefacts that could find tuning around the band.

73, Doug -- K0DXV