[Elecraft] K2 Audio issue

[Don Wilhelm]

Bob,

Your biggest problem is the 8 ohm impedance Icom speaker.  Most solid state
power amplifiers will deliver more power into a lower impedance load - the
K2 audio power output spec is for 1 watt max into a 4 ohm load - when the
audio output amplifier tries to work into an 8 ohm load, the power will be
reduced substantially - likely only 1/4 watt will be available.

The other part of the equation is the Sound Pressure Level (SPL) of the
speaker - that varies from one speaker to another.  The SPL of the K2
internal speaker is higher than normal (in part as compensation for the
relatively low audio power available), and while I do not know the SPL for
your Icom speaker, I would wager that it is not as high as the K2 internal
speaker, and therefore not as loud for the same driving power.

As stated many times by Wayne B., the K2 design criteria was for low receive
current consumption and that is one reason that the K2 has limited audio
power output.  The current consumed by a higher powered audio stage could
likely take more current than the rest of the receiver.

Those of us who want loud audio in the shack would do well to consider using
an external audio amplifier - at least that is the solution for me.

73,
Don W3FPR

> -----Original Message-----
>
> I have a K2/100 & an Icom 756Pro. I am trying to use a switch box
> to switch a Icom SP-21 8 ohm speaker between rigs. When I have
> the K2/100 connected to the SP-21 I have to turn the audio
> control way up to hear anything, but when I switch back to the
> Icom radio its audio output is OK. Is this due to the fact that
> the K2/100 has a 4 ohm output & the Icom has an 8 ohm output?
>
> Bob
> WB8DDI
> K2/100 # 4998
>