[Elecraft] Measuring Losses in an ATU

[K9MA]

I haven't tried it, but one way to measure the loss of the ATU would be 
to connect a second, identical ATU "backwards" to a 50 Ohm load. This 
second ATU would be tuned to present the highest or lowest resistive 
load possible.  One way this could be done would be by connecting a 
resistor across the transceiver output, matching it, and reading out the 
ATU component values.  The second ATU would be set to the same values, 
which should result in a match from the first ATU without retuning.  The 
measured loss would be twice that of a single ATU.

That said, it's very likely the maximum ATU loss would be at the highest 
frequency of interest and highest or lowest impedance the ATU can 
match.  Highly reactive loads might make it worse.  I suppose an 
automated test could explore all the possible combinations.

This could all be simulated, of course, if good models of the components 
are available.  I suspect most of the loss is in the inductors, but one 
needs to know more than their DC resistance.

73,

Scott  K9MA

-- 
Scott  K9MA

k9ma at sdellington.us