Frank,

So NEC4 cannot calculate input impedance of the radial system and we
have almost reached a dead end.

Would it be possible to insert a loading coil ( 2.48 uH ) at the
bottom of the antenna to tune out its input reactance ( which is what
my program does.)

Then repeat the efficiency calculation and tell me what you get.
----
Reg.

Frank,

So NEC4 cannot calculate input impedance of the radial system and we
have almost reached a dead end.

Would it be possible to insert a loading coil ( 2.48 uH ) at the
bottom of the antenna to tune out its input reactance ( which is
what
my program does.)

Then repeat the efficiency calculation and tell me what you get.
----
Reg.

===================================
Frank,

Alternatively, or in addition to, you could shift frequency nearer to
8.3 MHz where the antenna is resonant and its input reactance is zero.

And again do the efficiency calculation. Tell me what the efficiency
is and the frequency. Also the antenna input resistance.

You will see I am desperately trying to localise the discrepancy in
efficiency. It is either in the radials or in the antenna. You should
also learn something about NEC4.
----
Reg.

"Reg Edwards" wrote in message
...
Frank,

So NEC4 cannot calculate input impedance of the radial system and we
have almost reached a dead end.

Would it be possible to insert a loading coil ( 2.48 uH ) at the
bottom of the antenna to tune out its input reactance ( which is what
my program does.)

Then repeat the efficiency calculation and tell me what you get.
----
Reg.

Reg, According to NEC 4.1 the input impedance is near 40 ohms
(39.9373 + j 0.394926 ohms) at resonance (8.07 MHz). With
100 W input the total radiated power computes to 31.8 W. I am
continuing with checking the program to be certain I have not made
an error, and also working on a NEC solution to the input impedance
of one radial. Note that the computation also includes copper loss,
which should be insignificant. I have also included a copy of my
code below.

Frank

CM Reg's test Vertical
CE
GW 1 36 0 0 9 0 0 0.05
GC 0 0 .9 0.00082 0.00082
GW 38 3 0 0 0.05 0 0 -0.025 0.00082
GW 2 40 0 0 -0.025 0 10 -0.025
GC 0 0 1.11 0.00082 0.00082
GM 1 35 0 0 10 0 0 0 2 1 2 40
GE -1
GN 2 0 0 0 16 0.0067
FR 0 1 0 0 8.07 0.01
EX 0 38 2 00 89.37696044 0
LD 5 1 1 36 5.8001E7.......

........................

.........................
LD 5 36 1 60 5.8001E7
RP 0 181 1 1000 -90 90 1.00000 1.00000
EN