[Elecraft] K3 audio quality

[Fred Jensen]

A recurring theme on this list, Alan.  My hearing is sufficiently 
challenged that the only audio my K3 ever produces go into headphones, 
which are hugely improved over the "cans" on the mid-20th Century.  I 
have found that the internal speakers in many of today's transceivers 
leave a lot to be desired.  I find the K3 internal speaker to be in the 
lower part of the "audio quality" spectrum.  That said,

You can lay your headphones on the desk and still copy CW [old RO's 
trick for weak signals in noise].  You will also hear voice and it will 
be intelligible, but it doesn't sound good.  Mark this as one end of the 
quality spectrum

A number of years ago, I inherited a Hallicrafters SX-28 with the bass 
reflex speaker cabinet.  The cabinet is about belt-high, and about 50 cm 
wide and deep [receiver will fit nicely on top].  The speaker is about 
30-35 cm in diameter, and has a very large, strong magnet.  Internally, 
it has a baffle that directs the energy from the rear of the speaker 
back, around, and eventually out the bottom front ... a fairly long 
path.  The SX-28 uses two 6V6's in push-pull for 8 watts undistorted 
audio out.  It sounds fantastic!  Mark that as the other end of the 
quality spectrum.

I formed a theory long ago that speakers are like antennas.  A small 
antenna [relative to wavelength] will radiate, but not well.  Likewise, 
a small speaker will speak, but it does so best at higher frequencies. 
If you want balanced audio, you need apparatus that "radiates" well at 
longer wavelengths.  Electronic equalization can do a lot, but in the 
end, it's the "antenna" that makes the final difference.  My K3 has much 
less empty volume inside that my TS-950 did.  The 950 sounded better. 
My K2 has less empty volume than my K3, and predictably, sounds worse

I forwarded my theory to Stockholm ... just waiting now for the Nobel 
Committee to send me travel instructions.

73,

Fred K6DGW
Sparks NV
Washoe County DM09dn

On 9/16/2016 4:04 AM, Alan. G4GNX wrote:

> I wonder if I can get some feedback about K3 audio from the built in
> speaker. Please note that this is not a K3 bashing session, my
> comments are made as an enquiry based on observed facts.
>
> We have a K3 at the local Ham Radio club and we often get complaints
> that the audio from the internal speaker is not very good quality,
> even when signals are 5/9 and virtually no RF noise. I suspect that
> part of the reason is that the K3 is setup to someone’s personal
> preference, or not really setup at all! We made a comparison last
> week against a new Icom IC7300 which  also had an external speaker
> and the IC7300 ‘won’ hands down. At first I made an excuse that it
> was the external speaker, but we unplugged it and the IC7300 was
> still superior.