[Elecraft] External speakers for K3?

[Tom Hammond]

Brendan:

>For general communications use I am very fond indeed of the speakers
>Motorola made for their various mobile rigs over the years, They are
>very cheap, efficient and sound great for good quality communications
>audio. These are not Hifi speakers but for speech / CW they do a superb job.
>
>Mostly they seem to be a pretty close match in size and colour for the
>K3 too.

I agree completely.

>Some of them are 2 Ohm though, The ones I use with My K3 at the moment
>are 2 Ohm ones, Since I do not know for sure if the AF amp in the K3 is
>happy driving an impedance this low I stuck a 2Ohm 2W resistor in series
>with each speaker and still have more than enough audio in my shack.
>
>I have seen these available in 4-Ohm and amplified variants too. Pretty
>much every radio in the shack is connected to a Moto speaker and I still
>buy them at rallies, collecting stuff I might need someday must be habit
>
>Anyone know if the can K3 drive a 2Ohm speaker without bad stuff
>happening ?

In a recent e-mail from Lyle Johnson, KK7P, he stated that, while not
'designed' to drive 2-Ohm loads, the K3s AF amp should "probably" work
OK BUT that if one attempted to drive the speakers too hard, and the AF
amp attempted to draw excessive current (and starts to overheat), the amp
would go into a protective shut-down mode, rather than risk damaging itself.

For what it's worth, MOST (possibly all nowadays) of the newer, plastic-cased,
Motorola NON-amplified speakers are now 8-Ohms... there may be some 4-Ohm
speakers in the newer-style plastic ('fitted back') cases, but I suspect that
almost all have now been switched to 8-Ohm speakers.

I'm using a pair of 8-Ohm Motorola speakers on my K3 and it sounds just fine.

Cheers,

Tom Hammond   N0SS