[Elecraft] K3S TX current

[Randy Farmer]

The K3 PA is the original module, but I don't know what devices it uses. 
Perhaps someone with inside knowledge could provide a S/N range or 
approximate date for the changeover. I built my K3 from a kit in July 
2009. As I recall, It draws about 17.5A with key-down CW on 20 meters. 
The K3S PA module was replaced in July 2016. I don't know if the 
original K3S PA showed the elevated current draw before it was replaced.

73...
Randy, W8FN

On 9/6/2020 2:07 PM, ab2tc wrote:
> Hi Randy,
>
> Does your K3 #3260 have the newer MOSFET PA? I believe the K3 switched the
> PA from bipolar to the newer MOSFET design at some point (mine is #82!). I
> agree with you that the 20/30m LPF ought to be a prime suspect. Everything
> else is common and 14MHz should be very close to the center of the total
> frequency range of the transmitter. My K3S has not had any reliability
> problems either, but it sees fairly light duty with SSB only and no heavy
> duty "run mode" contest use.
>
> BTW, I checked the current draw on 30m (on the K3S) which *shares the same
> LP filter*. It is an average 17.5A. But 30m is lower in frequency and thus
> farther away from the filter cutoff. 40m, 15m and 10m LP filters are also
> shared with a lower frequency band, but do not cause an elevated current
> draw.
>
> Knut - AB2TC