An interesting issue just came up over on the Elecraft reflector about setting up the K3/K3S for digital that i thought might be of some interest to this group.
As you may know a K3 isn’t like most radios when it comes to the ALC meter. The first 4 bars of the ALC meter show the audio level below the threshold that the ALC kicks in.
Therefor, the Elecraft recommended method is to transmit a carrier and increase the audio drive until 4 bars are solid and the 5th bar is just beginning to flicker.
I could never seem to get 4 solid bars: the ALC meter would “pump” between zero bars and 6 or even 7 bars. K0DTJ finally figured out that if the radio was set to [Mhz] + 1500 hz (which is the center of the bandpass) this happened. By merely setting the radio to [Mhz] + 1350 hz (or +1750 Hz) this phenomena no longer occurred and the radio could be set precisely at the correct drive level.
The “pumping” or pulsing occurs when some process in the K3 is beating with any 500 Hz interval.
This has been bugging me for years and I was happy that Brian finally figured it out.
73 de Eric, KG6MZS