[Amps] PIC processor inside HF amp

[Matt Tucker]

>I'm thinking of putting a PIC inside my amp and having it run a LCD display
>out front. I've seen it done, but am curious about

Chuck,
I am also planning on putting a PIC inside my amplifier.  Of course I
won't be dividing down my voltages nearly as far since I am solid
state.  On the more recent subject of dividing down voltages, be sure
to use several resistors to drop the high voltage down to a level your
PIC likes (probably 1.2 - 5V depending on you A-D reference).  I
suppose tube builders know that since you deal with high voltages all
the time, but you would be amazed how many people try to use one 1/4W
or worse yet one 0805 surface mount resistor to drop 500V.

I am glad you brought this subject up.  Although I was planning on
doing some extra filtering, I probably was going to be under filtered.
I normally use the PIC16F87X uC for my projects. They have a 10 bit
A-D which is plenty for most applications.  I will probably just use a
1% 5V regulator for the PICs VCC and then use that VCC as the A-D
reference.  I don't need true 10bit accuracy as I don't really care if
temperature, V power supply, forward/reverse power is a few percent
off.... for me it is just eye candy.  Amplifier protection (I know
your tubes won't need much of that) will mostly come from analog
control as I am more familiar with analog and quite the hack when it
comes to uCs (I write my code in BASIC and use a compiler to get it to
HEX).  The uC will be able to shut down the amp if it sees to much
power being reflected just in case the analog section malfunctioned.
I am using a Wavenode sensor for measuring forwared/reflected power.

I will be interested on how it goes for you.  I'll keep you updated
with my progress.... it will probably be another month or more until I
start hacking some code out.

Matt