On 2 Aug 2005 05:44:15 -0700, "Professor"
wrote:

+Frank... the point you're missing is that although it's like you say
+"All CB radios are designed for a load impedance of 50 ohms."... there
+are certainly different reactances (j factor) from radio to radio. No
+radio or antenna is exactly 50 +j0. This is where the matchbox can help
+to supply the conjugate needed for maximum performance.
+
+Professor
+www.telstar-electronics.com
******

If we take the equation 50 + j0 ohms to be a 50 Ohm impedance then an
equation in this form, x + jy, will yield an infinite solution of
equatins where the magnitude of the impedance is 50 ohms.

Conversely 50 + j50 Ohms is not 50 Ohms impedance.

What does vary from radio to radio is the tuning of the output filter
and matching network. Still this variation is not much greater than
about 5%. That 5% variation will not alter the match between the radio
and the coax significantly.

Finally, SWR is not determined by the mismatch of the radio to the
coax. SWR is determined by the mismatch of impedance of the antenna to
that of the coax. SO variations of source mismatch play a relatively
small degradation in the system performance.

james