Elecraft XV Transverter Owner's Manual - Manual (Page 21)

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I.F. Overload Condition
The transverter switches to transmit mode when the transmit enable signal
is received from the 28 MHz rig. When used with an Elecraft K2 or K3,
this signal is supplied through the CONTROL connector. When used with
other 28 MHz rigs, this signal is supplied to the transverter KEY IN RCA
jack.
If the transverter fails to switch to transmit mode before a high-level
transmit I.F. signal is applied, a protective circuit will disable the
transverter. All of the front panel power display LEDs will flash in unison
to alert you that an overload condition has occurred.
An I.F. overload condition will occur if the transmit enable signal is not
present whenever high-level transmit I.F. is applied to the transverter.
This is normally the result of an unplugged cable or circuit failure, but it
may also be caused by a timing problem with the 28 MHz rig being used.
See Transmit-Receive Switching Delay below.
To clear the overload condition, turn the transverter power off, then on
again. (If you’re using the transverter with an Elecraft K2 or K3, turn the
K2 or K3’s power off then on again since the transverter power is
controlled by the K2 or K3’s power switch).
Transmit-Receive Switching Delay
When the transverter is used with rigs other than an Elecraft K2 or K3,
the transmit-receive switching is controlled by the signal furnished by the
28-MHz rig to the transverter TX KEY input. If the 28 MHz rig switches
the TX KEY line to receive before it stops transmitting, it will trigger in
I.F. overload condition in the transverter when using a high-level RF
drive from the 28 MHz rig (see I.F. Overload Condition above for
details). In the Installation section, you set up the transverter for a 200
millisecond delay to avoid timing problems. If your 28 MHz rig can
provide the switching speed needed, you can reduce the delay time to 50
ms by removing the shorting block on jumper JP1. JP1 is located on the
back of the front panel PCB between the left side panel and socket-
mounted processor U1.
JP1 Open – 50 ms delay.
JP1 Shorted – 200 ms delay (Default)
Front Panel Display Control
When used with an Elecraft K2, the front panel LEDs are controlled by
the K2 through the Menu commands. The Menu LCD DAY command
provides full brightness and the LCD NIGHT command dims the LEDs.
The GRPH Menu command controls the behavior of the K2 bargraph
and the Power Output LEDs on the transverter as follows:
DOT: Just one LED representing the power output will illuminate.
BAR: All LEDs to the left of the current LED will illuminate,
resulting in a more visible display.
OFF: The LEDs operate in DOT mode.
When used with the K3 or other 28 MHz rigs, the brightness of all the
front panel LEDs is fixed.