RT-600 Operations Manual
Version 1.0
14
Bypass
Whenever the RT-600 is turned off (Power button in the Off position, Status LED
off), the tuner is bypassed; RF from the amplifier is passed directly to the antenna
with no matching. When the tuner is powered up again, it restores the most recent
tuned state it held when last powered down.
Relay Protection
The RT-600 software disables tuning if the input power exceeds 200W, or 150W if
the SWR exceeds 3:1. This protects the relay contacts from arcing damage caused by
switching under high power. Always bypass your amplifier during tuning; you may
place your amplifier back in normal operating mode once tuning is complete.
Re-tuning Prohibition
In some rare cases, when an antenna is tuned far from its resonant frequency, the RT-
600 may erroneously attempt to re-tune even though it has already found an
acceptable match. In these cases the following procedure may be used to place the
RT-600 into non-tuning mode:
1.
Turn off power to the RT-600, wait for one full second.
2.
Turn on power to the RT-600 wait for one full second. Do not transmit.
3.
Repeat this cycle three times. In other words, turn power off and back on
slowly three times in a row, but do not transmit during this time.
The RT-600 is now in active, non-tuning mode; it will hold the current tuning
settings, but will not re-tune. This mode is useful for antennas tuned far from their
resonant frequency, where the final SWR match found by the RT-600 is perhaps
higher than usual. By placing the RT-600 in active, non-tuning mode, you can
transmit without the RT-600 continuously attempting to re-tune this high SWR load.
To return to normal mode, simply initiate a full tuning cycle: press the
Tune
button
on the RC-600, begin transmitting, and while transmitting release the
Tune
button on
the RC-600.
MARS/CAP Coverage
The RT-600 provides continuous tuning coverage over its specified range, not just in
the amateur bands. This makes it useful for MARS or CAP, or any other legal HF
operation.
The RT-600
automatically
protects itself
from tuning at
high power.
The RT-600
1.8-54 MHz
continuously,
not just in the
ham bands.
