[AMRadio] AM Radio

[Todd, KA1KAQ]

On Tue, Jan 24, 2012 at 3:25 PM, John Coleman <jc at pctechref.com> wrote:

> Idea 2.
> Reducing the loading for less plate current will cause a mismatch in the
> ratio of plate voltage to screen voltage and the screen current will be
> high.  Will work to some degree but not the best idea.

This is the generally-used method by most folks, though as John stated
- it's not the best idea as you'll be running things outside the
parameters they were designed for. Running below its design isn't
always good. I tried running a kw-input rig with lighter loading to
bring the power level down, but it objected strenuously by kicking out
the overload relay and sounded scruffy too.

What you seem to be asking for Rick, is a perfect answer to an
imperfect situation. You want to be able to run a DX-100 as if it was
a legal-limit AM transmitter. It was never designed to be that. Linear
amplifiers aren't designed as such either. Therefore, any attempts to
make it work will require compromises, and compromises are just that -
less than perfect, less than ideal, and more opportunities for
problems. The fact that others do something similar doesn't mean they
are doing so without issues, nor does it mean their solution will be
the best one for you even if it's a rig-and-linear set up.

The best approach would be to keep the DX-100 for low power operation
and build or buy a purpose-built rig capable of higher output, like a
Globe King, Johnson 500, etc. You could build a big rig for less than
either of those would likely cost you. Even a Class E rig would move
you into that direction, though limit your band coverage.

That would be my advice - build or buy bigger, and don't take
everything you hear or read too literally. We quite often describe
things in a way that makes perfect sense to us, not necessarily the
person we're describing it to.

~ Todd,  KA1KAQ/4