[Elecraft] K3 AM TX - Questions and Observations

[Joe Subich, W4TV]

Andy,

 > This is probably the reason it currently cannot be modulated
 > in excess of 100% positive. Maybe there will be an update in
 > the future?

You do not want more than 100% positive modulation with the K3.
If one assumes 25W of carrier, 100% positive modulation represents
100W peak power ... modulation greater than 100% positive would
result in limiting/compression in the final amplifier with its
attendant distortion.  To obtain greater than 100% positive
modulation (particularly in a low level modulation with linear
amplifier situation), the final amplifier must be capable of
PEP greater than four times the carrier power.

The only way the K3 could support more than 100% positive modulation
is if the carrier power were reduced and that would be rather
self defeating.

73,

    ... Joe, W4TV


On 5/11/2010 9:27 PM, Andy Wood wrote:
>
> Thanks for the reply Tom - your information is appreciated. I have been to
> your website a few times but I hadn't visited the AM page before. Lots of
> good information there. I had to read it a few times to take it all in.
>
> I have done some more research and it appears the K3 TX has a quite
> sophisticated, multiple loop ALC system. This is probably the reason it
> currently cannot be modulated in excess of 100% positive. Maybe there will
> be an update in the future?
>
> Andy  VK4KY
>