Table 4-2 Using Tri Tuning Aid - Acom 1000 User Manual

c) Tuning Procedure
While a continuous (CW) signal at the desired frequency is still applied:
Look at the upper scale (forward power). Obtain maximum power using the upper (TUNE)
•
knob;
Look at the lower (Load Cap) scale and turn the lower (LOAD) knob in order to center the
•
triangle marker at the "!" mark;
Release the PTT shortly in order to disable the attenuator, then repeat both steps at nominal
•
power. Always finish by peaking with the TUNE knob.
Appearance of an arrow on either left or right TRI scale edges means that the LOAD
knob is too far from the proper position. To correct for this, turn the LOAD knob to the
prompted direction until the triangle marker appears inside the scale field.
|
______!______
No marker:
Use TUNE knob for
max. P to get any
marker.
Please note also, that the TRI mark will not appear until at least 5W drive is applied, and at least 20W
forward power is achieved.
If, for some reason, matching cannot be accomplished successfully, check BAND switch and antenna
selection. Then check the antenna VSWR at the same drive frequency.
d) Tuning hints
While turning knobs, you'll note that both tunings would be virtually independent. This is a benefit of the
TRI. The plate-load resistance increases to the right and decreases to the left of the TRI center.
The center of the scale corresponds to the proper LOAD capacitor tuning, which presents an optimum load
resistance to the tube.
If you tune to the right, you'll obtain more gain, but less undistorted output power will be attainable. You
may prefer to use this hint when your drive power is insufficient or when you need less output but better
efficiency, for instance at heavy duty modes (RTTY, SSTV, etc.) where less heat is wanted.
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|||| |||||||||||||
>_____!______ ______!_____<
Marker is a far left: Marker is a far right:
Turn LOAD knob Turn LOAD knob
pointer to right until pointer to left until
marker inside. marker inside.

Table 4-2 Using TRI tuning aid

User's Manual | ACOM 1000 | HF + 6m Linear Amplifier
|||||||
______!__v___
Marker inside:
Turn LOAD knob
slightly left to
center it.
||||||||||||||||
______v______
LOAD is tuned:
Turn TUNE knob to
peak Forward Power
& finish.
August 2020