I have heard that before, but I have also heard that the real problem had
something to do with the physical layout of the solder runs on thePC board
(specifically the geography of the solder runs) and that the problem would
never be 100% fixed without a new layout of the board, which of course was
out of the question. I would have to search old emails to say exactly what
it was, and I have more important things to do right now than that.
BTW, this was a similar problem to the problem the Eagle has with this low
level audio hum which many think is a CPU processor hum. It's not. It was
actually fixed by one OM (forgot who) by swapping two similar circuits with
each other, which physically moved the problem to another location...and the
problem went away.
In any case, the K3 audio distortion is fixed with the K3S.
And the problem I mentioned with the Eagle is not really a problem.
You don't hear it when using the speaker, or external speaker, and when
using headphones, it depends on the impedance and frequency response of the
headphones. If you hear it at all, you only hear it if you have no signal
present and the audio volume turned way down low. As soon as you turn the
audio up and listen to a real signal, you can't hear the hum. So it is a
theoretical problem but not a practical problem.
73 - Rick, DJ0IP
(Nr. Frankfurt, Germany)
-----Original Message-----
From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Jim Brown
Sent: Thursday, December 10, 2015 10:29 PM
To: tentec@contesting.com
Subject: Re: [TenTec] Dirty Transmitters - Flex and Yaesu
On Thu,12/10/2015 1:04 PM, rick@dj0ip.de wrote:
> The K3 audio distortion problem was IMPEDANCE DEPENDANT.
> If you use headphones with 64 Ohms or more, you won't notice any
distortion. If you use a speaker with 4 Ohms or 8 Ohms, you notice a lot of
distortion.
If I'm not mistaken, there are separate output stages for phones and the
speaker.
The heart of the complaints with speaker audio on the K3 is that Wayne
Burdick, principal designer, is a backpacker at heart, his designs emphasize
low current drain, so his output stages tend to be current starved.
73, Jim K9YC
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