Re: [Elecraft] Problem with K3 driving old tube amp

Sounds as though ALC from the amp is causing the transceiver to step power.   One should NOT use ALC from the L-4B to the K3. The ALC circuit in the L-4B was designed for exciters which did not have precise power control.   The use of ALC to control power in this configuration is likely to

Re: [Elecraft] Problem with K3 driving old tube amp

Do you have the ALC hooker up? Kurt > On May 31, 2019, at 4:21 PM, William Stewart wrote: > > All, > > I am trying to bring a Drake L-4B to life. I have done the power supply > rebuild, the soft-start and other mods. I have also directly grounded the > grids of the 3-500Zs (Eimac brand). In

[Elecraft] Problem with K3 driving old tube amp

All, I am trying to bring a Drake L-4B to life. I have done the power supply rebuild, the soft-start and other mods. I have also directly grounded the grids of the 3-500Zs (Eimac brand). In driving it with my K3 (SN 51XX, software up to date) I find that the RF power stair-steps to the set