[ARC5] Help a Dummy Out on Modulation.

[David Stinson]

I don't understand something, so thought I'd ask the
people smarter than me...

Take a look at this diagram of a BC-230 transmitter:

http://home.netcom.com/~arc5/SCR-AH-183/BC230TX.JPG

If operated and tuned according to the manual, using the
called-for 4-ohm/100pFd phantom antenna and using a
normal, well-working carbon microphone, I can't get more than
30% moduation and about 40 mils of antenna current.
Tubes are good.
Now, I understand about the modulators not
delivering enough power to get 100% at full load, and the manual
says to keep the loading down so you can get more mod.  However-
no matter where I load the rig, light or heavy, tuned or mistuned,
I still get about 30% mod, unless I yell.  Even more funny- if I use an 
external
antenna tuner, a wire antenna and just tune for maximum "smoke,"
I get about 1.2 amps antenna current and nice, 100% mod!..... (tilt!).
To add more "huh?" to the mix- when I use one of the xtal-control
coil sets with a 3880 KC crystal installed, I get less power out
(probably due to lower grid drive), but I can over-modulate.
I'm scratching my pointy head on this one, guys.
What is it I don't understand here??

73 Dave S.