SSTC Break-Through - 5MHz operation for Ion Tweeter system

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "by way of Terry Fritz <teslalist-at-qwest-dot-net>" <dhmccauley-at-spacecatlighting-dot-com>

Tonight I made a big step towards a Hi-Fi solid state ion tweeter (aka audio
modulated SSTC).  The key to creating a Hi-Fi ion tweeter is to run at a
frequency of at least
3MHz.   The corona formation of anything less than 3MHz can be typically
considered "noisy" or "hissy", but once the 3MHz+ limit has been hit, corona
discharge is practically silent.
Typically tubes are used to easily get switching frequencies well over 12MHz
for ion tweeters, but solid state has always been limited to low frequencies
(<300kHz typically) due to the
inherent complexities of switching a high voltage at relatively high current
at high frequencies.  To my knowledge, the highest frequency obtained yet
for a solid state ion tweeter
has been by a group of doctorate students at Villanova University,
Pennsylvania where their SSTCs were operating at 3MHz.

However, my initial tests this evening have proven reliable operation at
5MHz with some very quiet, continous corona.  I haven't audio modulated yet,
but this is the first step.  My goal,
however challenging, is to get operation up to about 10MHz switching 170VDC.
At these frequencies, I think i can create a ion tweeter approaching Hi-Fi
characteristics although probably
never achieve the quality (at least in an audiophiles opinion) that tubes
can produce.

This is exciting news and I will be keeping the group posted.

The Captain