Yaesu FT-757GX II, Technical Supplement

Page: 5 / 70

ER RATA FOR T H E FT- 7 5 7 GX OPERAT I N G MA N UA L
The following corrections apply t o the first and
second printings o f the Operating Manual, with the
code numbers E3890183 and E3890183A, re­
spectively, on the back o f the rear cover.
First Printing Only: KEY plug requirements
The KEY jack on the rear panel o f the FT-757GX
will only accept a 3-conductor phone plug for
connection o f a CW key, keying paddles or an
external keyer. I f a 2-conductor plug is used, the
outer (ground) contact will be shorted to the sleeve
ring (dot) contact, and proper CW transmission will
not be possible.
The in formation stating otherwise on pages 13
(KEYER switch description), 20 ( MANUAL KEY
Plug drawing), and 28 (middle o f second paragraph
under CW Transmission instructions) is in error and
should be corrected accordingly .
•
First and Second Printings: QSK Linear Amplifier
Connections
The two lower interconnection diagrams on page
l 9 do not show the connections for the changeover
relay closure delay signal ("INH" in the FT-
757GX), which is required in order to protect the
QSK amplifier from premature excitation when the
transceiver is keyed, until the changeover relay
contacts in the linear are properly seated. To
correct the diagrams, another connection must be
shown to the rear panel o f the Linear in the upper
diagram, and a third conductor must be shown in
the QSK Linear Amplifier Connection Cable
drawing at the lower right, one end o f which
connects to pin 8 o f the BAND DATA plug. Later
printings o f the Operating Manual show screw
terminal connections on the Linear, and no RCA
plug on the Linear end o f the cable (just free
wires). The number o f the (optional) cable is
changed to T9101295A.
Schematic Diagram Correctio.n: R269 on the RF
UNIT
Early printings o f the Schematic Diagram of the
RF UNIT show the value o f R269 (bottom center,
near J27) as
4
70 ohms. This should be 150 ohms.
- 2 -