Yaesu FC-700 User manual

INSTRUCTION
MANUAL
FC-7
YAESU MUSEN CO., LTD
C.P.O. BOX 1500
TOKYO, JAPAN

YAESU
FC-700
ANTENNA COUPLER
GENERAL
The FC-700 isan ultra-compactantennatuner for thé FT-77 transceiver.Designed for
opération on thé 80 through 10 meter amateurbands (including WARC bands), thé FC-700
will provide a 50-ohmload to thé transceiverwhen thé feedpointimpédance of thé antenna
System is within thé approximaterange of10 ohms to250 ohms.
The FC-700 includes a built-in SWRand powermeter,providing 15 watt and150 watt
scales. Alsoincluded isan internai50-ohmdummyload,which maybe selectedinstead of
thé antenna for preliminarycoupleradjustments. A THRU position of thé bandswitch
also allows thé antenna tobe connecteddirectly to thé transceiver, bypassing thé tuning
circuit.
High-quality low-loss components are used throughout thé FC-700. The matchingfunction
it performs means thé transmitter can always "see" thé résistive termination for which it
was designed. The inhérentselectivity of thé FC-700 matchingcircuitry helps attenuate
harmonies too, thus reducing thé chance of harmonic-related TVI or out-of-bandémissions.
Please readthismanual inits entirety, soasto dérivemaximum benefit from your new
FC-700.

SPECIFICATIONS
Frequency coverage:
3.5
7
10
14
18
21
24.5
28
3.5-4.0 MHz
7.0-7.5 MHz
10.0-10.5 MHz
14.0-14.5 MHz
18.0-18.5 MHz
21.0-21.5 MHz
24.5-25.0 MHz
28.0-29.7 MHz
Input impédance:
50 ohms
Max. variation in load impédance:
approx. 10-250 ohms
Insertion loss:
0.5dB max.
Rear panel antenna connection:
UHF type connecter
Dimensions:
238(W)x55(H)x 180(D)mm
Weight:
2.0kg
SWRcalibration:
To5:l SWR
Maximumtransmitter power:
150WRF@50ohms
Power meter calibration scales:
15 W, 150W
MODIFICATION OFTHE FC-700 FORUSE WITH IHE FT-747GX
The relay and panel lamp in (he FC-700 require 8 VDC. supplîed
through thé DC8Vjack on Ihe rear of thé Antenna Tuner.
Although itis possible 10 use thé FC-700 without modification
by supplying 8V. from an external source, thé FT-747GX does
not offer suchvoltage.
Thismodificationallows thé FC-700 tobe operated from thé
DG13.5V outpui jack on thé rearpanel ofIhe FT-747GX. so that
thé FC-700 canbe switched onand off with thé tran^eiver. Be
sure to change thé DC8Vlabel on thé FC-700 to DC13.5Vafter
making this modification.
Remove thé covers from thé FC-700.
(1) Referring 10 Figure I. remove thé two BLACK wires from
thé meterlamp terminal, and connect thé one from thé
DC8V jack to thé solder lug near thé mêler (thé other is
not used).
(2) Install a 56-ohm. 2-watt resistor between thé meterlamp
terminal and thé solder lug with thé BLACK wire.
(3) Referring to Figure 2, remove thé BLUE wire from thé
terminal post on thé RL Unit.
(4) Connect oneendofa 100-ohm, 4-watt resistor to thé terminal
post. and connecl thé BLUEwire to thé other endof thé
resistor.
Modification is complète.Replace thé covers.relabel ihe DC8V
jackDCI3.5V, and connect this jack to thé +13.5V jack on
thé FT-747GX.
Install a 56-ohm, 2W Resistor
Remove & reconnect thé BLACK wire
Figure 1
Installa lOO-ohm, I/2W Resistor
Remove & reconnect thé BLUE wire
Figure 2
-2-

FRONTPANELCONTROLS AND SWITCHES
(1) Meter
The meter provides indication of thé SWRor
power level.
(2)SWRSET
This control sets thé sensitivity of thé SWR meter.
(3) Function Switches
REF/FWD Thisswitchsélects forward orre-
flected power indication on thé meter.
SWR/PO This switch sélects indication of thé
SWR or poweroutput on thé meter.
15W/150W This switch sélects indication of thé
outputpower level scales: 15or 150
watts full scale.
(4) TUNE
The TUNEcontroldrives a variablecapacitor
which providescapacitiveadjustment of thé coupl-
ing between thé transmitter and thé impédance
established by thé BAND switch and LOAD
control. The TUNE and LOAD controls are
adjusted for minimum SWR.
(5) BAND
The BANDselectorsélects thé appropriate tapon
thé maintuninginductor for thé band in use.
(6) DUMMY/ANT
This switchsélectseither thé antenna or connec-
tion to thé 50-ohm dummy load. When thé built-in
dummy load is selected, thé antennacouplertuning
controls are still in thé line, so preliminary adjust-
ment of thé coupler canbe performed. When this
button is pressed and thé BANDselector issetto
thé THRU position, only thé dummy load and
meterremain in thé circuit.
(7) LOAD
The LOAD control drives a variable capacitor
which adjusts thé coupling between thé antenna
feedline and thé main BANDinductor.
-3-

REAR APRON
(1) ANT
This isa standard UHF connecter for thé antenna
feedline.
(2) GND
Connect a goodearthground at this point.
(3) DC8V
The DC8V Une from thé FT-77 transceiver should
be connected hère, to supply thé meter lamp on
thé frontpanel of thé FC-700.
(4) INPUT
Connect thé coaxialcable to thé FT-77 ANT jack
at thispoint.
ANTENMA
FT-77 Séries
COAXIAL
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INSTALLATION
Connect thé antenna to thé rearpanel ANT jack,
and connect a 50-ohm coaxialcablebetween thé
FT-77 and thé FC-700. Connect thé DC cable
between thé DC8Vjacks of thé FC-700 and thé
FT-77. Connect a goodearthground to thé GND
terminal on thé rear of thé antennacoupler, using
a Keavy, braided wire less than 10 feet long for
connection to thé stationground bus.
When using a transceiver otherthan thé- FT-77,
be absolutelycertain to observe thé properpolarity
and level of thé voltageapplied to thé rearpanel
DC8V jack. Donot exceed 8 volts DC,nor apply
AC power ofany kind, to this jack. Our warranty
does not coverdamagecaused by improper power
connections to this equipmenî.
FT-77/FV-700DM/FC-700 (or FTV-700)/MMB-16
FT-77
FP-700
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ACCORD
-5 -

ANTENNA MATCHING PROCEDURE
THIS SECTIONSHOULD BE STUDIEDCARE-
FULLYBEFORE USING THE FC-700. WHILE
A STRAIGHTFORWARDPROCEDURE, AN-
TENNA MATCHING WITH A COUPLERSUCH
AS THE FC-700INVOLVES A LOGICAL
PROGRESSION OF STEPS, AND FAMILIARITY
WITH THE TOTALITY OFTHE FOLLOWING
SECTION WILL AVOID POSSIBLEDAMAGE TO
THE EQUIPMENTCAUSED BY INCORRECT
ADJUSTMENTS.
To summarize thé procédure that is followed in
using thé FC-700antennacoupler to match a feed-
line to thé transmitter, thé following process takes
place:
1) The proper inductance is chosenusing thé
BAND selector.
2) The LOAD and TUNE controls are adjusted
to secure a minimum SWR. Thèse two
controls should be adjusted oneata time,
soasto avoid confusion asto thé effect of
any particularadjustment. A typical pro-
cédure to follow would beto apply power,
adjust thé TUNEcontrol for minimumSWR,
then adjust thé LOADdirectioneither to thé
right or left.
Once thé LOADcontrol has been changed,
thé TUNEcontrolshouldagain be adjusted
for minimumSWR; if this procédureimproves
thé SWR, it should be continued by further
moving thé LOADcontrol in thé same direc-
tion, butif thé initialchange in thé LOAD
controlworsens thé SWR, move thé LOAD
control in thé oppositedirection. It will be
clear to thé operatorwhen thé LOADcontrol
is beingadjusted in thé rightdirection.
Refer to Figure 1, where thé approximatepositions
of thé BAND,LOAD, and TUNEcontrols are
shown for matching toa 50-ohm load. The internai
dummyload is used to preset thé controls for thé
operatingfrequency. The antenna may then be
selected, with final tuning taking only a few
seconds.
(1) Setup thé FT-77 or other transceiver for
normal opération. Set thé DUMMY/ANT
switch to DUMMY to sélect thé built-in
dummy load.Reduce thé drivecontrol on thé
transceiver to thé minimum, and place thé
transmitter in thé "standby" condition for
thé moment.
(2) Place thé BAND, LOAD, und TUNE ton trois
in thé positionsshown in Figure 1 for thé
frequency nearest that at which thé antenna
is tobe matched. Set thé functionswitches
to thé FWD, SWR. and 150W positions. Set
thé SWR SETknob to thé 12 o'clock position.
(3) Make preliminary matchingadjustmentswith
as littletransmitterpower as possible.Place
thé FT-77 in thé "transmit" condition (CW
and press PTT), and slowlyadvance thé
drive until deflection of thé meter needle
on thé FC-700 is observed. Adjust thé
SWR SET control to align thé meterneedle
with thé SET marking on thé meter scale.
Now switch thé FWD/REVswitch toREV
for accurate reading of thé SWR.
(4) Adjust thé TUNE control for minimumSWR.
If necessary, adjust thé SWRSET control
and/or transmitterdrive to ensureproper
calibration (be certain to check thé SWR
meter sensitivitywith thé FWD/REVswitch
in thé FWD position,thenswitchback to
REV).
Once thé "dip" has beenfoundusing thé
TUNE control,move thé LOADcontrol a
small amount in eitherdirection, left or right.
Adjust thé TUNEcontrol fora "dip" again,
andif thé SWRis lowered, move thé LOAD
control slightly more in thé samedirection as
before.Again "dip" thé TUNEcontrol, and
continuethisprocédureuntil no further
improvement is noted. If thé initialdirection
of adjustment of thé LOADcontrolmakes
thé SWR higher,move thé control an equal
distance in thé oppositedirection from thé
starting point, and "dip" thé TUNE control.
Remember to recheck thé calibration of thé
SWR meter to avoidmisleadingreadings.
-6

(5) Once thé initial procédure has beenfollowed
to yield a near-perfect match, thé transmitter
may be adjusted for tu 11 power, and thé
FC-700 LOAD and TUNE controls-may be
adjusted to yield zéro deflection of thé SWR
meter. When thé SWR meter isnot calibrated
Witll thé SWRSET control. it will notac-
curately read thé SWR, butit will indicate
minimum reflected power. Donot exceed thé
maximum key-downtimestipulated for your
transmitter,
(6)Nowset thé DUMMY/ANT switch to ANT.
Following thé technique described above,
tune your antennaSystem soasto secure
minimum SWR with thé antenna.Always
begintuning atlow power, to avoidpossible
damage to transceiver or coupler components
from unknownimpédances.
BAND
3.5
7
10
14
18
21
24.5
28
FREQ
3.5MHz
4.0MHz
7.0MHz
7.5MHz
10.0 MHZ
10.S MHz
14.0 MHz
14.5 MHz
18.0 MHz
18.5 MHz
21.0MHz
21.5MHz
24.5 MHz
25.0 MHz
28.0 MHz
29.7 MHz
TUNE
4.5
5.5
6.0
6.0
6.5
7.0
G. 5
7.0
7.5
7.5
7.5
8.0
7.0
7.0
7.0
7.0
LÔAD
7.0
7.5
7.5
8.0
8.0
8.5
B.3
8.5
9.0
9.0
9.0
9.0
9.0
9.0
8.5
9.0
Figure 1
CM COUPLER
UNIT
TCio
RL UNIT
Top View
-7-

NOTES ON ANTENNA MATCHING
(1) It is veryimportant that thé maximumtime
limits during tune-upconditions for thé
transmit ter arenot exceededwhen thé trans-
mitter is beingused at full power.
(2) Any matching perfbrmed by thé FC-700
in thé shack will hâve no effect on thé
lOSSeS duetoSWRon thé coaxial Une
between thé FC-700 coupler and thé antenna.
The operator shouldconsult oneof thé
popularantennahandbooks to détermine
whether ornot matchingbetween thé
coaxial line and thé antennamust be per-
formed at thé antenna. For example, a 100-
footlength of RG8A/U coaxtypically hasa
loss (with 1:1SWR between itand antenna)
of less than 1 dBat21 MHz. If this line is
operatedwith a 3:1 SWRduetoa low or
high antennaimpédance, thé loss duetoSWR
will increaseroughly 0.5 dB,#n imperceptible
dégradation as compared to thé 1:1 condition.
In thiscase,attempts to reduce thé 3:1SWR
at thé antenna end would serve no useful
purpose asfaras reducinglosses in thé coax,
through matchingwith thé FC-700 would
improve thé impédancepresented to thé
transmitteroutput circuitry- However, ifa
500-footlength of thé abovecoaxwereused
instead of oniy ioo feet, somewliat more
than 1 dBof loss would occur in thé ooflv due
to thé 3:1 SWR, possibly justifyingfurther
matching attempts at tlic untciinu.
(3) When using a transceiver such as thé FT-77
which has protection for thé outputtran-
sistors againsthighSWR, itcanbe seenthat
thé matchingaction of thé FC-700 will ensure
that a 50-ohm load is presented to thé output
circuitry,thus ensuring full transmitter power.
(4)Itmaybe useful for thé operator to record in
a notebook thé properTUNE and LOAD
positions fora particularantenna for quick
référence. Alternatively, appropriate labels
may be fabricated and applied to thé FC-700
front panelshowing thé properpositions of
thé TUNE and LOAD controls fora particular
frequency.
JOf
FC-70Q
CIRCUIT DIAGRAM
-8-

PARTS LIST
! MAIN CHASSIS RELAY UNIT
Symbol No.
VR01
VC01
VC02
MOI
SOI
J01,02
J03
LOI
L02
C13
Cil
C06
C07,08,10,12
C(J4,Ù5,09
C03
C02
COI
C14,15
Part No.
J6080070
K90000029
K90000028
M0290020
N0190069
PI 090028
PÛ090093
L0020799B
L0020800B
K 3 0309 005
K3 0309001
K30309004
K 3 03 09006
K30309011
K30309010
K30309009
K30309008
K13170103
Description
POTENTIOMETER
VM10A949C-50knB
VARIABLE CAPACITOR
YB-290, 290pF
YB-430, 430pF
METER
SY-50 DC 200MA
SWITCH
SRS4.49
RECEPTACLE
M-BR-06D
X-G9242
INDUCTOR
Symbol No.
D201
C201
RL201
Part No.
C0021240
F0002124
G2090001
K13170473
M1190025
Q5000011
Description
P.C.B with Components
Printed Circuit Board
DIODE
10D1
CAPACITOR
RELAY
MR-31
Wrapping terminal C
SWITCH A UNIT
Symbol No.
S301
Part No.
C0021250
F0002125
N4090034
Description
P.C.B u-ith Components
Printed Circuit Board
SWITCH
SUT31A
^3i^^^tf&X ° SWITCH B UNI 1
CAPACITOR
Dipped mica IkWV 47pF
75pF
150pF
180pF
300pF
330pF
910pF
ISOOpF
Ceramic disk 50WV 0.01*jF
CM COUPLER UNIT
Symbol No.
D101.102
R102
R103.104
C101
Cl02
VC101
T101
L101
Part No.
C0020560
F0002056A
G2090038
J01245430
J00245103
K30176471
K13170473
K91000019
L0020301A
L1190017
Q5000011
Descnption
P.C. Bwiih Components
Prinîed Circuit Boaid
DIODE
1SS16
RESISTOR
Carbon film I/4WTJ 43îï
VJ lOkfî
CAPACITOR
Dipped mica SOWV 470pF
Ceramicdisk " 0.047MF
TRIMMER CAPACITOR
ECV-1ZW 10x40, lOpF
INDUCTOR
FL5H-102K ImH
Wrapping terminal C
Symbol No.
D401
S401
R401
Part No.
C0021260
F0002126A
G 2090 134
N4090035
J00245561
Description
P.C.B With Componenis
PrintedCircuitBoard
DIODE
LED TLY-205
SWITCH
SUT12A
RESISTOR
Carbon film 1/4WVJ 560n
VR UNIT
Symbol No.
VR501
VR502
R501
R502
Part No.
C0021270
F0002127
J5 1723472
J51723223
J00245102
J00245332
Q5 0000 11
Description
P.C.B with Components
Printed Circuit Board
POTENTIOMETER
SR-19R 4.7kîlB
22kfîB
RESISTOR
Carbon film 1/4WVJ Ikîî
3.3kïl
Wrapping terminal C
DUMMY LOAD UNIT
Symbol No.
R601-620
C601
Part No.
J20375102
K3130900I
Description
RESISTOR
RSF-5BJ 5W Ikîî
CAPACITOR
Mica IkWV lOpF
ACCESSOR1ES >
Symbol No.
Part No.
T9101220
T9100160A
R3054370
Description
Connection cable
Plastic Foot