[Elecraft] Audio Volume

[Ron D'Eau Claire]

Stuart, K5KVH, wrote:
Make sure your speaker bolts are not overly tight distorting the speaker
voice coil travel.  This was a problem on a number of units.

Reply: ----------------

BENT SPEAKER

Some speakers arrived at the builder bent so the voice coil rubbed, but that
was pretty obvious and not just a low-volume issue. Even CW tones were
obviously distorted. Mine was one of those, and I found it was very easy to
bend the frame. Indeed I fixed it that way with a large screwdriver to gain
leverage between the edge of the magnet and the frame! 

Apparently during travel somewhere between China, where it was made, and
Oregon via Aptos and other places unknown, the speaker was subjected to
enough shock to bend the frame. After messing with it I have no doubt that
would be easy to bend the frame by dropping the speaker, in its padded box,
from a perfectly typical height encountered in shipping that would produce
no other indication that the box or the speaker had been abused. It takes
very little force at all. The weight of the heavy magnet suddenly "stopping"
does the bending. 

Like the problem with over-tightening the bolts, it's all a matter of a very
light-weight and bendable metal frame on the speaker. 

MORE VOLUME

If there's nothing on top of the K2, one can make a significant increase in
the volume for a listener in front of the radio by simply providing a
reflector. A stiff piece of paper shaped in a curve and angled over the
speaker opening so the sound bounces off and forward will make a big
difference. 

My impression of the post that started this thread was that the operator
needed more than a doubling or tripling of the audio level though. I'm
inclined to agree with those who suggested that there is something wrong in
the audio channel of his K2. 

Ron AC7AC