.PS
cct_init

# Usual defs...
qrt=dimen_/4;
hlf=dimen_/2;
dim=dimen_;

S1:source(up_, AC)
linethick_(3);
line right_ 43mm__ from S1.end 
line right_ 43mm__ from S1.start 

spline from 2nd last line.end right 20mm__ then right 20mm__ up 15mm__
spline from last line.end right 20mm__ then right 20mm__ down 15mm__

linethick_() # Default

# Field lines
line -> up at S1+(10mm__, 0)
"$\stackrel{\textstyle E}{\scriptstyle\sim}$" at last line.center ljust
line <- up at S1+(20mm__, 0)
line -> up at S1+(30mm__, 0)
line <- up at S1+(40mm__, 0)
line -> up at S1+(50mm__, 0)

# Antenna arcs 
# Look better centered on the throat :-)
S2:S1.center+(40mm__, 0)
r=20mm__;
d=7.5mm__
arc -> cw rad r from S2.center+(r,d) to S2.center+(r,-d) with .center at S2

r=30mm__;
d=12mm__
arc <- cw rad r from S2.center+(r,d) to S2.center+(r,-d) with .center at S2

r=40mm__;
d=19mm__
arc -> cw rad r from S2.center+(r,d) to S2.center+(r,-d) with .center at S2

# FreeSpace arcs.

r=50mm__;
d=28mm__
arc <- cw rad r from S2.center+(r,d) to S2.center+(r,-d) with .center at S2

r=60mm__;
d=30mm__
arc -> cw rad r from S2.center+(r,d) to S2.center+(r,-d) with .center at S2

arc cw rad 4mm__ from last arc.end to 2nd last arc.end
arc ccw rad 4mm__ from 2nd last arc.start to 3rd last arc.start
right_
S3:S1.center+(0,-40mm__)
line dashed from S3+(10mm__, -5mm__) to S3+(10mm__, 5mm__)
"Generator" at S3
line dashed from S3+(50mm__, -5mm__) to S3+(50mm__, 5mm__)
"Transmission line" at 1/2 of the way between last line.c and 2nd last line.c
line dashed from S3+(80mm__, -5mm__) to S3+(80mm__, 5mm__)
"Antenna" at 1/2 of the way between last line.c and 2nd last line.c
"  FreeSpace" at S3+(95mm__,0)

"\tiny AlpineHorn" at (2*dim,-1.75*dim)
.PE