[TCML] Antenna DC component and other questions regarding the feedback issues

[TheBypasser <bypasser@xxxxxxx>]

Hi again! So far I tried that generator prototype with an antenna rigged  
up to it's input. The effect is weird - on my 6-turn primary until 150vac  
I barely get any significant sparks (around 10cm at that voltage), after  
that point the spark length begins to grow very fast, @240vac I get ~40cm  
with a barely any good deadtime (will find a double-beam scope to check  
the gates and set a proper value) and up to 60 with a deadtime set to a  
somehow better value (again, I'm sure it's still too high).

http://i8.photobucket.com/albums/a44/TheBypasser/snapshot20080707210703.jpg


Looks like the optos are doing their job well and their CMR is enough,  
will try another secondary as soon as I get a wire for it because I fear  
that mine could have some damage after a few arcovers it suffered, but  
first will try to set the deadtime properly.
The question is - does the antenna get any DC current flowing through it?  
At first glance it seems it can not as it's just a capacitive coupling  
with the coil's output, however the dynamics of plasma in the spark itself  
(which is actually not a streamer at all, it's more of an arc - the  
initial short streamer (as stremers can't ever be long at such voltage as  
the streamer is being ionized purely by electrons accelerated by the E  
field and the the optical radiation of the ions themselves) is heated up  
by the field up to the point a new streamer forms up on the top of it's  
channel and the sequence continues while the power is enough to both keep  
the arc burning and have some minor extra voltage to form a corona on the  
end of it, this is proved by the behavior of sine-modulated sparks as seen  
on vttc or half-wave sstc for example, where the power rises smoothly,  
thus making the initial arc heat more and get a more pronounced shape,  
make a single-beam corona on it's top and therefore finally becoming a  
straight sword-like discharge - sorry for a long detour :) ) suggest that  
the spark growth happens only on the negative half-cycle, thus a dc  
current may probably flow through an object located close to the coil. At  
least on some coils a significant charge is seen to form up on their  
insulator and persist after the coil is switched off. So, should I add a  
DC blocking cap after the antenna?

By the way I saw some antenna feedback-based projects and still wondered  
why do people use a diode fork straight before a schmitt input? I'm sure  
(and of course I did that in my system) you need a resistor after the fork  
so the diode reverse voltage will not make the full current drop on the  
schmitt internal input diodes, but instead crop the input so that the  
shmitt input cropping current will never be exceeded.
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