It's kind of funny watching the thread about the mobile amplifiers and voltage requirements.
Here, we learned long ago (on 11 meters) how to fix this problem.
The 11 meter crowd calls it a "dead motor maul", and it's nothing more than a bank of pass transistors (or mosfets, if the builder knows what he's doing) that act as a regulator.
They use a charging system consisting of a 24 volt alternator, and run parallel / series combos of standard car batteries (or standard and deep cycle, if they are smart) to have a 24 volt electric system. One alternator, and a pair of batteries will power quite a large system, as long as the number of active devices in the regulator is up to the job.
This allows you to do a number of things, but vary the collector voltage from < 11 volts to > 20 volts is possible. Run a regulator to the bias section of the amp to keep bias in check and runaway in check, and you can run 16 volts on the collectors easily.
I have a 12 volt 16X2SC2879 amplifier that produces > 2400 watts PEP at 15 volts. This is a bootleg cb amplifier produced by Messenger years ago. It has a simple 10 meter filter on the output, which I can't measure the effectiveness of due to lack of equipment. Stock, it ran > 1 volt of bias on the base of the transistors, and would toast them at > 14 volts (like, a stiff charging system, with long periods of keydown, here's another 300 dollars in transistors). I redid the bias circuit with different diodes (a diode feeding / clamping each pair of transistors) and a 12 volt regulator with a pair of pass transistors feeding the bias regulator. This keeps things a lot better running higher Vcoll than afforded with the stock "regulated" system of nearly any amplifier.
--Toll_Free
