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With the unit in simple "Test Mode", I am experimenting with manual operation - so, basically to perform the tuning the same as the Autotune function, but doing it manually.?

However, I'm not sure about the correct sequence of steps to do this - but here's the steps I am performing currently for use with my FT8 Software (WSJT-X):

1) Power up the tuner in Test Mode and set values of C and L to zero;?
2) Activate "Tune" function of the software to transmit RF input signal to the tuner;
3) Increase C value one step, note the effect (if any) on SWR;
4) If SWR decreases, continue to increase C value until SWR is minimum; if SWR does not decrease, then increase L value in similar way to get minimum SWR;
5) Repeat the steps 3 and 4 again to minimize SWR after each time C or L is adjusted - do a "fine tune" essentially;
6) Once minimum SWR is achieved, "long press" the "TUNE" button to change the filter configuration and repeat the above process - best SWR result will determine which configuration is preferable.
7) Deactivate the "Tune" Function.? The tuner is now set for the current operating frequency.

Does this sound correct ?? I am not trying to reverse engineer the operating program - only to understand it...? ? ? ?:-)

Any comments, suggestions or or improvements to my process listed above will be greatly appreciated - Thanks.

73,?

Dave KG7WOC

Hi Dave

Perhaps it would be a good idea to let the tuner work in auto mode to start with and make a note of the L and C values determined by the ATU. Then switch to manual mode and use these values as a starting point.?

I find adjusting the values of L and C manually in Test mode slow and tedious (compared to a traditional ATU with a variable capacitor) I think lots of adjustment with values way off the mark while transmitting will stress the PA,(and possibly the ATU capacitors if using higher power), particularly if it is a simple radio with no protection such as the QCX or QDX.

Certainly an interesting exercise though Dave

73 Steve G4EDG