[TenTec] "A low vswr will kill you ! "

[Jim Reid]

Dr. Jerry wrote,  in part:

> There is no conjugate match to the output of any active 
> source.....

> All those that demand conjugate matching through to the 
> active device are wrong.
 
> Its given the more maddening appearance of there being
> a conjugate match because of the way RF solid state devices 
> are measured. Commonly they are installed in a test jig, and 
> the universal matching network is adjusted for maximum power 
> output (a side effect on conjugate matching of no time varying 
> components) and then the test jig is split and the Z shown to 
> the active device is measured and its conjugate declared the 
> output Z of the device. It is NOT. The impedance measured is 
> the load the allows the active device to produce maximum
> power (within distortion and efficiency and gain limits). For circuit
> designers, it is convenient to say the output impedance of 
> the device is r + jx and the load then must r - jx to be a 
> conjugate match but that's an improper statement of fact. 
> Its plain wrong, but it makes circuit designers produce output 
> networks that supply the appropriate load for the device.
> 
> During any one cycle of RF the output Z of the active device 
> varies from open to nearly shorted and that's nothing that
> can be matched by a constant impedance. Any time the 
> active device is a constant impedance, its not producing any 
> output, its output Z MUST VARY to produce output.
> 
> But if the load Z is set for the available voltage swing to produce 
> the desired output power, the power supply is saved and the 
> power output is controlled.

Now,  if only Bruene had been able to state what Dr.  Jerry has
given us in the above so clearly....... Instead,  Bruene set about
to anyilate Walt Maxwell's work via charactyer assiination alomost!



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