[Elecraft] K3: 630m amplifiers

[Alan]

The need for linear amplifiers with CW has been known for many years. 
Quoting from the 1964 ARRL Handbook:

    When key clicks introduced by the addition of an amplifier stage
    are found only near the transmitter frequency, amplifier "clipping"
    is indicated.  It is quite common when fixed bias is used on the
    amplifier and the bias is well past the "cut-off" value.

[In other words, a class C amplifier.  Similar to a bipolar transistor 
amplifier with no base bias.]

    A linear amplifier (Class AB1, AB2 or B) will amplify the
    excitation without adding any clicks, and if clicks show up, a
    low-frequency parasitic oscillation is probably the reason.

Alan N1AL



On 07/27/2015 11:42 AM, Jim Brown wrote:
> On Mon,7/27/2015 10:43 AM, Edward R Cole wrote:
>> CW, JT65, FSK all do fine with class-C, of course.
>
> Ed,
>
> I suggest that you drive a Class C amp with a K3 transmitting CW and
> look at the spectra with a P3 both at the output of the rig and at the
> output of the amp. Set the P3 display for 5 kHz.
>
> 73, Jim K9YC