BCA94024 Barrett 940 automatic antenna tuner
Barrett BCA94024 940 automatic
antenna tuner - colour periwinkle
- clips onto 940 portable transceiver to make it a manpack transceiver
- operates with 10 metre long wire supplied or optional 3 m
collapsible whip (BCA94019).
Includes:
- 10 metre long wire antenna with plug.
- Cable 100mm control 8pin female to 8 pin female.
- Cable 100mm BNC to BNC.
The Barrett 940 automatic antenna tuner is a fully featured automatic
antenna tuner designed for operation between 1.6 and 30MHz at power
levels up to 25 Watts with either a whip or long wire antenna. The
tuner uses a switched "L"configuration with 256 capacitor, 256
inductor and Hi/Lo-Z settings to provide over 131,000 tuning
combinations. An input balun with impedance ratio of 16 to 1
transforms the whip impedance to a range that can be handled by the
L
and C combinations. Tuning time is between 0.1 and 3.0 seconds with
an
average time of 1.5 seconds. The tuner will only tune when commanded
to by the 940 transceiver with a low pulse appearing on pin 6 of the
8
pin connector.
Four LEDs provide an indication of SWR and status. The green LED
marked "<1.5" indicates SWR of less than 1.5, the yellow LED marked
"2.0" indicates the SWR is 1.5-2.0, the red LED marked ">3.0" indicates
the SWR is greater than 3 and that a bad match has occurred. This
happens occasionally with some combinations of antenna length and
frequency. The red LED marked "TUNING" indicates the tuner is in a
tune cycle.
The 940 antenna tuner front panel provides a stud for whip antenna
mounting via a gooseneck. Next to this are binding posts for
connection of an earth and a wire antenna. RF input to the tuner from
a 940 transceiver is via a BNC connector. One 8 pin panel mounted plug
provids connection to the 940 transceiver the other connector
providing connection to auxiliary functions and power input etc.
The unit is fixed to capstans provided on the 940 transceiver with
over-centre clips.
WARNING -Do not feed more than 25 Watts PEP two tone RF power into
the RF input connector.