I have a pair of 3-500z tubes in my final. For tune up, I set 200ma grid,
600ma plate on cw mode. Then, I back off just a little, and switch to SSB
mode. The question I have is whether there is any need to use ALC with my
final. There are several reasons I ask this:
1. I seem to do fine without ALC. I have a scope on my xctr and final
output, and have one and two tone test capability for signal monitoring.
2. In the past, when I did use the ALC, I got squirrelly results in tuning,
from time-to-time, and therefore lacked confidence in the results. When
that happened, I would disconnect from ALC, and go back to tuneup without
it. The squirrelly results had nothing to do with the ALC. It was just
there trying to do its job. Other factors were at work in the squirrelly
tuning result. But, the ALC, in trying to do its job, was
complicating/masking other problems.
3. I get excellent on-the-air reports without ALC.
4. I have several tranceivers that I can use to drive the final. Of the
three, only one was designed to be compatible with the ALC of this final.
Of the three, they all work fine as exciters.
So, is there a strong case for ALC, when the capability is there? Are there
any particular problems with not running ALC? I only have a few years
experience using high power finals, and would like to hear from those who
have been around them a lot longer than I have.
73 de Ron, K5BDJ
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