[Elecraft] K3 SSB Power Control and ALC Metering

[d.cutter at ntlworld.com]

This reminds me of the IC706 (I think) which has a spike leading edge which shuts down an Alpha (which has protection circuits) but not a Heathkit for instance.  Or is it just the power control itself which is faulty?

David
G3UNA
> 
> From: "Kamal Sirageldin" <ksira at corpten.com>
> Date: 2008/09/25 Thu AM 03:35:12 BST
> To: <elecraft at mailman.qth.net>
> Subject: [Elecraft] K3 SSB Power Control and ALC Metering
> 
> Michael,
> 
> I also see the exact same symptoms you describe below.  This is after
> implementing Wayne's procedures 'to the letter.'  Firmware V2.38,  K3 S/N
> 775.
> 
> 73,
> Kam  N3KS
> 
> Thanks for the detailed information. However, this is not my problem. 
> 
> The most severe problem I have is:
> 
> a) the output power spikes and overshoots in CW or SSB or FM as you adjust
> the power control, so it is not advisable to use a sensitive, i.e solid
> state power amplifier with the K3. Especially not one needing less than 50W
> of drive. It needs a fast responding meter to see it. 
> 
> A work around is to set the power without the amplifier in circuit, speak or
> key to let the spike happen, then switch on the PA and not adjust power or
> mode afterwards.
> 
> Does this not happen to anyone else?
> 
> A lesser problem is:
>  
> b) that the power output is unstable once set in SSB mode, showing
> variations of around 50-100% in the peak output depending on the power
> output setting. This is when set up as described. It is only really visible
> with a peak reading power meter.
> 
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