[Elecraft] K3: 630m amplifiers

[Wayne Burdick]

CW also requires a highly stable ALC system, without unwanted dynamics, to preserve ideal envelope shaping. This is lacking on some all-mode rigs that pay little attention to CW.

Wayne
N6KR

On Jul 26, 2015, at 9:32 PM, Alan <n1al at sonic.net> wrote:

> 
> > CW would be another mode that would not need a linear amp I think.
> 
> No, CW requires a linear amplifier.  CW is not constant-amplitude - the amplitude changes every time you open or close the key.  A class-C amplifier would mess up the key shaping, causing key clicks.
> 
> Any true FSK or MSK signal should not be bothered by a non-linear amplifier.  The only caveat I can think of is that the amplitude of an AFSK signal may have some ripple on it to the extent that the passband of the transmit crystal filter is not flat.  But I doubt that's a significant issue.
> 
> Alan N1AL
> 
> 
> 
> On 07/26/2015 06:57 PM, Tom Azlin W7SUA wrote:
>> Hi Don and Alan,
>> 
>> I was thinking one of the slow multi tone FSK modes that are a single
>> tone at a time. WSQ is in the same class.
>> 
>> http://www.qsl.net/zl1bpu/SOFT/WSQ.htm
>> 
>> CW would be another mode that would not need a linear amp I think.
>> 
>> On the other hand PSK31 would require a linear amp.
>> 
>> 73, tom w7sua
>> 
>> On 7/26/2015 5:43 PM, Alan wrote:
>>> On 07/26/2015 05:32 PM, Don Wilhelm wrote:
>>> 
>>>> Soundcard sourced digital modes are really SSB signals and need a linear
>>>> amplifier.
>>> 
>>> The one exception might be FSK.  It is constant-amplitude so a class C
>>> amplifier should be fine.
>>> 
>>> FSK modes include RTTY and I believe WSPR and WSJT.
>>> 
>>> Alan N1AL
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>> 
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