Figure 4-1 Using Tri Tuning Aid - Acom 1500 User Manual

By pressing repeatedly either PREV or NEXT button (whichever is nearest), until you reach
•
the TRI scale.
This will not insert the attenuator, so you will have to use less than 20 W drive (unless the
amplifier is nearly correctly tuned), otherwise the next step would be executed
automatically;
By simply applying a normal working (60-85 W) drive power, while the amplifier is not yet
•
tuned.
This will automatically invoke the TRI tuning aid and will insert the input attenuator (the ATT
LED will light) after one second. The attenuator will be switched off, and the old screen will
be returned automatically, after you release the PTT shortly.
If you have achieved meanwhile a nearly good tuning, the attenuator would not be inserted
again. If the old screen was the same (TRI, selected manually earlier), you will then be able to
precisely tune the amplifier also at nominal power, without changing drive at all. Use this
hint to shorten the tuning process duration.
c) Tuning Procedure
While a continuous carrier (CW key down, RTTY or FM) 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 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 5 W drive is applied, and at least 20 W
forward power is achieved.
Page 28 of 52 | S e c t i o n OPERATION

Figure 4-1 Using TRI tuning aid

|||| |||||||||||||
>_____!______ ______!_____<
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.
Figure 4-1 Using TRI tuning aid
User's Manual | ACOM 1500 | HF + 6 m 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 2021