[Elecraft] K3 RF-out spikes, was: K3 SSB Power Control and ALC Metering

[Charles Harpole]

Yep, my recently factory re-done K3-100F #309 also

has RF output power spikes upon first key down or

first SSB word spoken.  The spike appears to be

at fully 120 watts when rig is adjusted to 50 watts.

When oh when will this rig be at least half way 

done?  73,


Charles Harpole

k4vud at hotmail.com






> From: ksira at corpten.com
> To: elecraft at mailman.qth.net
> Subject: [Elecraft] K3 SSB Power Control and ALC Metering
> Date: Wed, 24 Sep 2008 22:35:12 -0400
>
> 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.
>
> _______________________________________________
> Elecraft mailing list
> Post to: Elecraft at mailman.qth.net
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
> http://mailman.qth.net/mailman/listinfo/elecraft
>
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com