|[AMRadio] AF67 question|
CL in NC
mjcal77 at yahoo.com
Sun Jan 21 17:54:15 EST 2018
I've got an AF67/PMR7/M1070 up and running. In lieu of the 22.5 volt battery, I put the unused winding meant for the vibrator supply to work and its making bias for the modulators and have it set to 22.5 volts. The problem is, I can not find a spec for the modulator idle current, only that it should swing to 60-70% of PA current, which is does. Is there an mod idle current spec?
The other issue is grid drive. I have plenty, actually too much for a single 6146. It seems if I detune the grid a bit to lower the grid drive, I can approach 120ma plate current under load with great power out and modulation. I know there is no clamper in this unit, and no grid drive means max plate current and that may be playing into the equation as I lower it. Do you Elmac'rs just peak it out, or maybe roll grid drive back to 2.5-3ma range?
Charlie, W4MEC in NC
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This page last updated 22 Feb 2018.