[Elecraft] SSB IMD

[Alan Bloom]

On Tue, 2009-01-27 at 01:58, Julian, G4ILO wrote:
> Bill W4ZV wrote:
...
> > ...I would never intentionally run mine at the lower end of that range. 
> > If you have any concerns about overshoot when turning on your power
> > supply, always turn the PS on a few seconds before the K3.
> > 
> 
> But the K3 power switch is a "soft" switch isn't it, so some electronics are
> still connected to the supply even when the switch is off?
...

The K3 has a transient suppressor that should blow the fuse if a big
enough transient appears on the power connector.

Looking at the RF board schematic I see a BZW50-15 overvoltage
protection diode connected between ground and +12V on the radio side of
the fuse.  I downloaded the data sheet for that part - it looks like the
breakdown voltage is 16.6V minimum at 1 mA.  The actual clamp voltage is
a complicated function of peak current and pulse width, but presumably
Elecraft chose a part that adequately protects the radio.

Al N1AL