Starting Up And Main Functions; What Is Tuning Type / Rate (Selectivity Degree, Sharpness) - Acom 06AT User Manual

4. STARTING UP AND MAIN FUNCTIONS

Operating the tuner is straightforward and intuitive due to the high degree of automation.
You may start operating right after installation. However, in order to make a better use of the tuner features,
and to fully adapt it to your particular environment, we recommend reading through the following
information.
Never operate the tuner with its cover removed! Touching the components inside the
tuner while transmitting may result in RF burns and injury.
Never exceed tuner specifications! Do not transmit with a high SWR!
When you use ACOM 06AT with ACOM 2020S amplifier do not use antennas with SWR
above 2.5! Always observe section

4.1. What is tuning type / Rate (Selectivity Degree, Sharpness)

This tuning feature indicates how significant are the changes in the quality of impedance matching between
the antenna and amplifier as a result of small changes of the operating frequency. This determines the
necessary width of the frequency segments required in a band, so that a sufficient degree of matching is
retained within any particular frequency segment. Accordingly, the tuning settings made and stored in the
tuner memory will be usable in a specific frequency segment, narrower or wider, depending on the nature
of the antenna used to do the settings.
In addition to narrowing the frequency segments and, respectively, increasing their number per band, the
high sharpness of tuning generally leads to higher heat losses and greater instability of the settings in time
or due to environmental changes.
It is clear that, by all criteria listed above, it is preferable that the tuning rate (sharpness) be as low as possible,
in order to have a few wide frequency segments, with low heat losses and stable (to external impacts) state
of tuning.
Unfortunately, the tuning sharpness cannot be chosen in a random manner. The specific frequency-
impedance characteristics of each antenna determine a minimum of the tuning sharpness (minimum
Q-factor of the tuned antenna circuit in the tuner), which cannot be further reduced, unless heat loss is
introduced by design (which, however, would lead to lower efficiency).
E.g., antennas with reduced dimensions, often used for 160 m and 80 m, or at higher frequencies, recently,
which are "loaded" with coils close to the maximum current or with "capacitive hats / caps" at the maximum
voltage across the length of the antenna, are normally tuned critically, or "sharply".
Page 30 of 70 | S e c t i o n STARTING UP AND MAIN FUNCTIONS
User's Manual | ACOM 06AT | Automatic Antenna Tuner and Switch
CAUTION
NOTICE
8.1.3 Maximum Allowed Input Power
!
October 2022