Elecraft KAT500 Owners Manual - Manual (Page 22)

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The KAT500 bypasses the matching L/C network when no values are stored in memory and the
SWR it presents is below the VSWR thresholds set for each band. You can change these thresholds
and erase any L/C settings already memory for those bands using the Utility Program (page 20) as
follows:
 In the Utility program under
Configuration/Edit Configuration
, click on the
VSWR
Thresholds
tab and set the
Autotune
and
Bypass VSWR
thresholds above that which your
antenna will present on each band. Typical values are 2.5: or 3.0:1.
 Click on the
Erase Memories
tab and erase the memory for each band.
 Be sure your antenna is connected and, if necessary, tuned for the band, and then select the
desired
ANT
and perform a Tune operation (see page 16). The KAT500 will perform a
brief search and, noting that the SWR the antenna presents is below the threshold you set
above, bypass the matching network. The antenna selection and bypass setting will be
stored in memory. The next time you return and transmit that band, you will hear a brief
click as the matching network is bypassed automatically, even if you are in
AUTO
mode, as
long as the antenna presents an SWR below the thresholds you set above.
 You can verify that the KAT500 matching network is bypassed using the Utility program.
Click on the
Operate
tab and note that a check appears next to
Bypassed
when you
transmit even though the KAT500 is in
AUTO
or
MAN
mode.
Signal Audible at 28004.5 MHz:
In some installations a 28004.5 MHz signal may be heard from an oscillator in the KAT500. If this is an
issue, you can cause the KAT500 oscillator to shut down when it is not needed with a setting in the Utility
program. See Idle Sleep on page 20.
Fault Conditions
A fault will occur if:
 The RF drive power exceeds 110 watts during a tune operation. This protects the relays from
damage due to excessive RF power while switching. If this fault occurs, be sure you have the PA
Key circuit installed, either through the E850463 Aux cable or using separate key line cables (see
Setup, page 3). As supplied, your KAT500 will not open the key line if 30 watts or more of RF
drive is applied. If your amplifier is capable of switching its key line at greater powers, you can
increase the limit using the Utility program (see Amplifier Key Interrupt Power, page 17).
 The impedance of your antenna is outside of the tuning range so an acceptable SWR cannot be
found.
 The impedance of your antenna is outside of the normal tuning range but the KAT500 is able to
match it. In that case, the allowable power is reduced as needed to protect the KAT500. You can
safely operate at any power less than that at which the fault occurs.
Reset a fault by tapping the any switch on the KAT500 or by switching the KAT500 power off, then on
again with the
MODE
switch.