RadioBanter - View Single Post

June 22nd 05, 02:54 AM

On Tue, 21 Jun 2005 14:11:17 -0600, (H Nelson BIG in
TEXAS!!!!) wrote:

Vinnie i have three I-Max 2000 That the center section cap flashed over
causing very bad TVI SWR ok. I cut them open and that is what i found.
They worked ok with the RCI 2990 But when i used the X Force 612 hd the
center section cap would flash over and carbon track.
I do not know what this cap is for
I asked on this group but couldnot get any help. I run the amp at 500 w
and pep 1000. I have ordered a WOLF point 64 11 M. No coils or caps to
burn out.
When I get time I am going to elimenate the cap and see what happins.

Triple 5
Trip 555
BIG in TEXAS
*******

Inserting reactive components in the antenna has the effect of
lengthening or shortening the electrical length of the antenna. IF the
antenna is physically less than a quarter wave an inductive load is
added anywhere between the feed point and the end of the antenna to
effectively make it a quarter wave antenna electrically. Capacitive
loads do the reverse. They take physically long antenna, a quarter
wave, and shorten them electrically.

All reactive loads alter feed point impedance and the "Q" or bandwidth
of an antenna. If my memory serves me correctly the IMAX is
essentially an end fed 5/8 wave antenna. FOr Solarcon to use the same
feed system that they do on the A99, they must raise the feed
impedance. This can easily be done by inserting a capacitor anywhere
in the antenna. Preferable this should be about a 1/4 from the feed
point. That is where the current in the antenna is at maximum. The
volatge the the cap must withstand is a minimum.

Removing the cap will most likely screw up the matching of the
antenna.

james