[Elecraft] (no subject)

[Don Wilhelm]

Don,

Are you plugging a 4 ohm speaker into the headphone jack?  Use the 
external speaker jack instead.  The speaker should have a high SPL 
rating if it is to produce sufficient output from the K2.  The internal 
speaker is a high efficiency (high SPL) speaker.  If you wish to use a 
low efficiency speaker, you will have to add an external audio amplifier.

There are resistors in the headphone jack circuit to raise the best 
impedance match to about 32 ohms, so the common 32 ohm or higher 
headphones will work best.  Low impedance HI-FI headphones will not work 
well at the K2 headphone jack.

The K2 was designed for low receive current drain so it could be used 
for portable QRP operation with good battery life.  The result of that 
design decision is that it does not have a powerful audio amplifier 
which would wast battery current with the audio amp's required high 
idling current.  The end result is that there is not a lot of reserve 
audio power in the K2 for driving a wide variety of external speakers.

73,
Don W3FPR

Don Latham wrote:
> Hello out there:  I seem to have a low audio volume problem with my K2.
> Installing the dsp kit seems to improve it somewhat, but not totally.
> Everything else is working very well; I have yet to hear a better
> receiver!
> I'm using the phones jack, and a 4 ohm speaker. Headphone volume is also a
> little low (my old Archer 8 ohm phones). Anyone know what the voltage
> level at the input to the output amp should be?
> Thanks
> Don
>