[Elecraft] [K3 / K3S] KIO3B NF

[Joe Subich, W4TV]

On 2015-07-04 12:11 PM, Hisashi T Fujinaka wrote:
 > Do you have any background info on this? I don't remember getting a
 > schematic or board layout with my SignaLink and if I did, I don't
 > know where I'd find it.

Signalink do not provide that data.  Most of the issues are summarized
here: http://www.frenning.dk/OZ1PIF_HOMEPAGE/SignaLinkUSB-mods.html
including links to other sources, modifications and reverse engineered
schematics.

73,

    ... Joe, W4TV


On 2015-07-04 12:11 PM, Hisashi T Fujinaka wrote:
> On Sat, 4 Jul 2015, Joe Subich, W4TV wrote:
>
>> Most Signalink units can be improved at least 6 dB by improving the
>> noise bypassing (decoupling) on the 5V bus within the unit, adding
>> proper filtering to the USB 5V input, and replacing the voltage divider
>> used as a reference for the CODEC and audio op-amps with a low noise
>> 2.3 V regulator.  Signalink's transmit quality can be improved to a
>> significant degree by turning down the CODEC output (Windows "slider")
>> to prevent distortion in the CODEC and clipping in the op-amps then
>> use an external PTT signal.
>
> Do you have any background info on this? I don't remember getting a
> schematic or board layout with my SignaLink and if I did, I don't know
> where I'd find it.
>