Hello Stefan,
This email I wrote five years ago may help you:
Hello Tom,
I have used your spreadsheet from the ANSI EMI Antenna calibration spec C
63.5 1998 to verify my measurements on different whip length's, from 1
metre
to 10 cm, in 10 cm increments.
whip length C-whip ONO-399.5 calculated
=======================================
100 cm 8.718 pF 0 dB 0 dB
90 cm 7.978 pF -0.5 dB -0.8 dB
80 cm 7.227 pF -1.1 dB -1.6 dB
70 cm 6.646 pF -2.2 dB -2.3 dB
60 cm 5.686 pF -3.2 dB -3.7 dB
50 cm 4.890 pF -4.5 dB -5.0 dB
40 cm 4.072 pF -6.0 dB -6.6 dB
30 cm 3.224 pF -8.5 dB -8.6 dB
20 cm 2.332 pF -11.1 dB -11.5 dB
10 cm 1.364 pF -16.5 dB -16.1 dB
I am very pleased to report that the results agree very well indeed. The
largest deviation is only 0.6 dB.
Thus before making a new whip, the performance can be accurately
calculated,
using a 1 metre long whip as a reference.
<<<<<
Best regards,
Roelof Bakker, PAoRDT
N.B. I can't locate the spreadsheet at present.
|
