Swann 400 Installation guide

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OPERATION AND MAINTENANCE
S\^'AN MODEL 40()
Osrrr
ELECTRONICS
Oceanside,
Ca
ilornia

OPERATIONandMAINTENANCE
MODEL 4OOSERIES
S]NGLE SIDEBAND TRANSCEIVER
INTRODUCTION
The Swan Model 400 Single Sideband
Transceiver, together with its acces-
sorre6 and optional equiprnent, is
designed to be used in either CW or
SSB mode6 on all portionB of the 80-,
40-, 20-, l5-, and I0-meter amateur
radio bands. Operation on AM (Single
Sidebaltd rrith Carrie!) is possible by
zero-beating the !eceived signal.
The Swan 400 generates the single side-
band signal by mean6 of a crystal lattice
filter, and the tran6ceive op€ration auto-
matically tunes the transmitter to the
receivedfrequency. Provi6ions a!e
included in the transceiver Jor ope!a-
tion on either upper or lower sideband,
and provisiong for cohplete band
coveraSe are included within the basic
Ba6ic circuitry of the single conversion
de6ign has been proven in thouaands of
hours ot opeiation of the very popular
Swan 240 and 350 series of transceivers.
Mechanical, electrical, and thermal
stability are exceptionally high, and all
oscillators are voltage legulated and
ternperature cornpensated. PuBh-to-
talk opeiation is po6sible in aU installa-
tiolrs, and operation with a tv,/o-contact
microphone is possible by use of the
FuDction Switch or the VOX accessory.
The basic tlansceive! iB deBigncd
for
use with either the Model 410 Frequency
Control Unit, which provides full covei-
age of all portions o{ the amateur bandd,
or with the Model 4068 Frequency Colttlol
Unit which providea coveiage of all phone
portiona of the 80 throrrgh l5 rneter bandE
and a 500 kc portion of the l0-meter
band, With a suitable power 6upply,
operation may be fixed, portabl€ or hobile.
Power input on all banda exceeds 400
Watts, PEP, on single sideband, and
320 Watts DC input on CW. The baaic
t
ranaceiver includeB autoDatic gain
control, (AGC) automatic lirniting control,
(ALC), aelectable sideband, grid-block
keying, calibrator, and speaker
Part I of this Manual covers the basic
transceiver. Parts II and lfl cover the
Models 4068 and 410 Frequency Conttol
Unita, !e6pectively. Part IV covers the
recohEended power Bupplies, Model
ff7-XB or ll?-XC lor ac operation
and
Model l4-ll7 for l2 volt dc operation.
Models a!e also available for 230volt
AC oDeration. O.cmr
ELECTRONICS CORP.

I MODEL 4OO
TRANSCEIVER
SPECIFICATIONS
FREOUENCYRANGES
Foll frequencycoverageof 80, 40, 20,
I5, and l0 meter amateur radio bands
in 8 ranges oJ 500 kc each, as Iollows:
3,5-4.0,7.0
-7.
5, t3.85-14.35,21.0-
2r,5, 28.0-28.5, 28.5
-29.
0, 29.0
-
29.5,29.2-?9.1rnc.
Model 4068 Frequercy Contlol Unit
Full phoneband coverage of 80, 40,
20, and l5 meters, plus a 500
kc
segmentof l0 lneters, as follows:
3
.
8
-4.
0, 7
.
r
-7
.
3
, 14.r5
-r4.35,
21.25
-21.45,
28.5
-29,
0 rnc.
POWER INPUT
bands.
cw
-320 Watts DC input on all bands,
AM (Sinsle Sideband With Carrier)
IZ5 Watts DC input on all bands.
DISTORTION
Distortion products downat least30 db.
UNWANTED SIDEBAND SUPPRESSION
Unwanted sidebaDddownat least40 db.
CARRIER SUPPRESSION
Carr:ier suppression at Ieast 50 db,
RECEIVER SENSITIVITY
Less than 0.5 Inicrovolt at 50 ohms
irnpedanc e for 6ignal-plus-noise to
noise ratio of I0 db.
AUDIO OUTPUT AND RESPONSE
Audio output through built-in speaker
approx. 3 watts to 3,2 ohrn load.
Response essentially flat 300 to 3000
cps on both teceive and transmit.
METERING
PA Cathode current, 0-800 rrla on
tran6mit S-Meter, 0-?0 db over 59
FRONT PANEL CONTROLS
Function Switch, Sideband Selector,
Phone-CW, AF Gain, Bandswitch'
Mic. Gain, Carrier Balance, PA Plate
Tune, PA Grid Tune, PA Load Coarse,
PA Load Fine, VOX-PTT
REAR PANEL CONTROLS
AND CONNECTORS
Bias Potentiometer, Grid -Block CW
key jack, Jones plug powe! connecto!,
VOX Connector, F requency Control
Unit Connecto!, Antenna, S-Meter Zero,
SPDT Relay Terrninal.
FREOUENCY CONTROL UNIT CONTROLS
Bardswitch, Main Tuning, RF Gain
2
VACUUM TUBE COMPLEMENT
Vl - 6EW6 VFO Amplifier
YZ - IZBE6 Transrnitter Mixer
vJ - ou.t\.o.urrver
V4 - 6HF5 Power Amplilier
v) - bill ) rowe r Arnprlri er
V6 - IZBZ6 Receiver RF Amplifier
Y? - IZBE6 Receiver Mixer
V8 - 6EW6 First IF Amplifier
V9 - l28.q.6Second
IF AmPlifier
Vl0 - IzAX7 Product Detector/Receiver
Audio
6BN8 AGC Amplifie r/ Detector
6GK6 Audio Output
l2I}A6 I00 KC Cryslal Calibrator
7360
Balanc€dModulator
12I}A6Carlier Oscillator
IZAXT Mic. Amplifier / Transrnit
Vl?- OAZ Voltage
Regulator
DIODE AND TRANSISTOR COMPLEMENT
QI,i 2N70
6Oscillator
QZ* 2N706
Emitter Follower
D40l TS
-2 ALC Diode
D4oz TS
-2 ALC Diode
D60l TS
-2 S-Meter Delay
Dl?01 IN29?4AZener VoltageRegulator
i. Transistor cornplement identical for
eithei Model 4I0 or Model 4068
Frequency Control Unit.
TRANSMITTER OUTPUT IMPEDANCE
Wide
-
range Pi-network output matche8
antennas
e6sentiallyresistive at 20 to
300 ohms impedance with provision8 for
both coarse and fine adju6t,
POWER REOUIREMENTS
vtr-
ylz-
vl3-
vl4 -
vl5-
vl6-
Filarnents
ReIay
Bias
Medium Voltage
High Voltage
DIMENSIONS
12.
6 volts, 5.5 amp
12volt6 dc, 250ma
-
Il 0 volts dc, 100rna
2?5volts dc, 150
ma
800 volts dc, 500 rna
Model 400 Transceiver
5-l/2 ir'. high, l3 in. wide, IL in. deep
Model 410 Frequencv Control Unit
5-l lZ A, t^rgn, 6-l/2 in. wide, I I in.
deep Control Unit
3 in, high, 1-3/4ir,. wide, 5 in. deep.
WEIGHT
Mode] 400Transceiver:
Model 410 Frequency Control Unit
Model 4068 Frequency Control Unit
t7lb, '-
91b.
3 lb.
Sinele Sideband Su Car!ie!
400Watts PEP,

PART I MODEL 4OO
TRANSCEIVER
CIRCUlT THEORY
GENERAL DISCUSSION
The Sr
ran 400 Transceiver plovides siagle
sideband,
Buppressed
ca!rier tran€ceive
operation; and generates the Bingle side-
band eignal by mean6 of a crystal lattice
filte!. To permlt a logical diEcussion of
thi6 lnode of operation, certain definitions
ate nece€5aly, In a normal AM signal
(double dideband
with carrier), a radio
frequency i6 modulated with an audio Jre-
quency signal. This is considered by
many to be merely a ca8e of varying the
amplitude of the carlie! at an audi.o
rate.
In fact, howeve!, there are actual.ly side-
band frequencies generated which ale the
!eBults of mlxing the RI. and A!' 6ignal3.
These sideband3 are the suh ot, and the
difference between the two hetelodyned
6ignals. For detection by means of
conventional diode detectols, the two
sidebands are mixed with the carlier to
detect aDdto demodulate the audio
intelligence. This inef{icient hean€ of
transrnis sion p€rrnits only approximately
25 per cent of the full tlanahitted power
to b€ used to tras6lnit intelligence.
There are other attendant drawbacks,
also. The bandwidth of the transmitted
6igna1is on the order of 6 kc, while the
actual dehodulated audio is 1e66than
3 kc. The lesult i. very limited use of
the band, and over half of the allotted
frequency range iB unuaablebecauge oI
heterodyne6, ioterference, and congestion.
In the single sideband, suppressed carlier
rrode of transhioeion, only ono sideband
of the Rr. and AF heterodyned signal is
tranBmitted, the other sideband and the
carrier being Buppressedto a level which
effectively permits using only the audio
intelligence bandwidth. This results in
increasing the transrnission efficiency
many times ove!, and pellnits an effec
-
tive doubling of the use of the allocated
frequenciea.
It rnust be remerrlbered that in the single
aideband, suppresned calrier mode of
transhission, both the unn,antedside-
band and the calrier ale oaly Buppressed,
not entile1y eliminated. Thu6, with a
transmitted sigDal frorn a transmittei
with 40 db sideband 6uppression, the
other, or unwanted sideband is pleBent,
and it i6 transrnitted, but its leve1 is
40 db below the'wanted sideband. When
3

I MODEL,lOO
TRANSCEIVER
A. Circuit Theory (cont)
BLOCK DIACRAM, RECFJIVE
B],OCK DIACRAM, TRANSMIT
FIGURE
3 CRYSTALFTLTER,
TYPTCAL
CHARACTERISTIC

I MODEL 4OO
TRANSCEIVER
A. Circuit Theoiy (Cont)
this signal is leceived at a level of 20 db
over 59. the unwanted sideband will be
pre6ent at a leve1 oI approximately 55.
The sahe is true of carrie! guPPression.
With carrier suppression
of 50db, and
a signal
level of 50
db over 59, carlier
will be present at a level of approxirnately
53 to 54.
In the Model 400 Transceiver, the single
sideband,
suppressed
carrie! signal is
generated by the crystal lattice filter
method. Refer to the schematic diagram'
and
to FiSule6 I and 2, Block Diagrams
SIGNAL CENERATION
In the TRANSMIT position (i. e., when the
pu6h-to-talk switch on the lnicroPhone i3
pressed ot when the Function Switch is
moved to TRANSMIT), the transmitter
portion of the transceivel is activated,
and generates a sinSle sideband,
suppressed
ca!!ier signal
in the follow_
ing manner: Carrier is Senerated
by Vl5,
Carrier Oscillator, which is a Pierce
oscillator, with the crystal oPerating in
parallel resonance. This stage operates
in both th€ ttansoit and leceive rnodes.
When transmitting, the RF outPut oJthe
oscillator is injected into the control grid
of the Balanced Modulator, VI4. This
balanced modulato! is a beam deflection
type, and opeiates 5imila! to a cathode
ray tube in that the elect!on bearn frorn
the cathode i6 deflected to one outPut
plate or the other by the charge aPPear_
ing on the deflection Plates. The RF
energy fed to the cootrol Srid of the
balanced modulator appeals on both
plates oI the output, in the absence of
signals to the deflection plates. The two
output plates feed the carrier to Trans_
forrner Zl40I in push PuU, and the two
RF signals cancel each other out in the
output ot the transforn:rer. The defl€c -
tion plate reference voltages are adjusted
bv means of the ca!rier balance control
60 that with no audio, the RF being Ied
to the output plates will cancel out' and
the output lror'j. Zl40l will be zero,
Audio from Microphone Amplifier Vl6
is superilnposed on one deflection Plate,
thereby unbalancinS lhe modulator, and
the two sideba$ds resulting froh the 3uln
and diff€rence frequencies of the audio
and carrier appear as a double sideband,
suppressed carrier si8na1
in the outPut
o{ Translormer Zl40l. The catrier
suppression is aPproximately 50 db.
The double sideband, suPPressed
carrier
siSnal is then couPled to the crystal filter'
which euppreeees one sideband, and
permit6 the other sideband to be fed to
the First IF Amplifier, V8. The carrie!
frequency crystal alrdthe filte! crystalg
are selected so that in the LSB poBition
on 4Oand 8Ohete!s, the sideband siSnal
is Senelated
with a calrier frequency
of
5l?2. 8 kc, and this siSnal \till fall within
the bandpass of the filt€r 6uch that the
lower 6idebandwill be attenuated by at
least 40 db. See Figure 3. On the USB
positronof 40 and 80 meiers, the carrier
clystal is 5I?6.8 kc, which positiond
the
double 6ideband signal on the other side
of the response culve oJthe filter,
attenuating the upper sideband by at
Ieast40 db. In lhe single conversion
mixing proces6, these sidebands become
inverted.
OnZ0, 15, and l0 meters, where oPera-
tion i6 generally on upPer sideband, the
siBnaI
i6 generatedwith the same carrier
crystal used in generating the lower side-
band on 40 and 80 meters. The five
crystal filter used in the tranaceive!
results in an improved reaPonae
characteristic on the low frequency end
of the bandpass, and advantage is taken
of this eflect to provide better sideband
suppression on the lnost used 6ideband
for each frequency band,

I IV{'IEL 4OOTRANSCEIVER
A. C
i.cuit Theory (Cont)
The single sideband, suppressed carrier At the sarne tirne, one d€flection plate of
signal Jrom the First IF Amplilier is fed the balanced rnodulator is grounded, un-
to the Transmitter Mixer, V2, u'here balancing the modulator and allowing full
signals Irom the VFO Amplifier are carrier input for tuning puiposes, A
mixed, and the resultant signal at the similar procedure is followed in the CW
final transmitted frequency is alnplified position of the Phone -CW switch, to allow
through the Transrnitter Mixer, the full carrier output duiing CW operation.
Driver, V3, and the Power Amplifiers, During CW operation the cathode of V168
V4 and V5. The signal from the VFO i6 opened from grotrnd, cuttrng ofI the
Amplifier iE initiated in the particular tube. This allows CW operation with no
Frequency Control Unit being used. The danger of pickup of audio through an open
signal frorn the Frequency Control Unit microphone, Attempts to operate on CW
is routed to the VfO Amplilier, and on by keying the lnicrophone jack, and insert-
40 and 80 rneteis, is subtractively ing carrier, are not recommended.
mixed with the single sideband signal
from the IF AmpliIier. On 20, 15, and RECEM
l0 meters, the frequencies are additively
mixed, resulting in output on the opposite In RECEIVE position, or at any time when
sideband, the transrnitter is not in TRANSMIT or
STANDBY, all circuits used in transmitting
When in TRANSMIT, thc gain oI the First are disabled throrgh the relay controlled
II Amplifier is controlled through the circuits, thc relays being energized Ior
Automatic Limiting Control network transmitting, and de-energrzcd for receiv-
D40l-402, etc., to control the gain of ing. Rclay K2, when de-energized, allows
the stage in response to the average in- signals frorn the transrnitting tank circuit
put power to the power amplifiers. This and antenna to be ted to the Receiver RF
ALC system will cornpensat€ {or any Amplifier, V6, where thcy are amplilied,
extremely strong input signaLs, but does and then {ed to the control giid oI the
not completely eliminate the necessity of Receiver Mixer, V?. The local oscillator
proper adjustrnent ol the Mic. Gain signal from the VFO Amplifier is now
Control. Although this feature wil] used to heterodyne the received frequency
prevent the transmitter Jroln flat-topping to the IF frequency, either upper or lower
and spurious ernissions, considerable sideband. A11IF arnplification is
distortion may occur if the Mic. Gain accomplished at this Jrequency, nominally
control is not properly adjusted. Refei 5l?4.5 kc, and in the Product Detector
to Operating Instructions. Vl0A, the IF lrequency is heterodyned
with carrier frequency generated by
TUNE AND CW OPERATION Carrier Oscillator, VI5, to res$lt in
detection of the sarne sideband used to
Normally, the Jrequency oJ the carrier generate the transmitted signal. It i6
oscillator is approximately 300 cps out- thus not possible {or the transceiver to
side the passband of the crystal lattice receive a 6ignal on any frequency other
filter. In TUNE position, to enable the than that to which the trarlsrnitter is tuned,
transmitter to be tun€d to the maximum nor to detect the wrong sideband. This
power output condition, the frequency of simple single conversion de6ign results
the carrier oscillator is moved approxi- in an extrelnely stable signal, and an
mately 500 cps to place it well within image response down more than 80 db.
the passband ofthe cry6tal lattice filter, Since the VFO frequency from the

1 MODEL 4OO
TRANSCEIVER
A. Circuit Theory (Cont)
Frequency Control Unit is deterrnined by
circuit elements which are far removed
frorn any heat source, and the voltage
regulation is very precise to the transis-
tor oBcillator, frequency stability is
extiemely good.
Automatic Cain Control, (AGC) is pro-
vided by the AGC Amplrfier/Detector,
VlI, which provides an AGC signal for
control of the gain of V6, Receiver RF
Amplifier, V7, Receiver Mixer, and V9,
TRANSM]T AND RECEIVE SWITCH]NC
AII transmit and receive ewitchrng i6
performed by relays Kl and K2. In
TRANSMIT position, only those tubes
that opelate in the transmit mode a!e
operative, aU others being biased to cut-
off through the relay contacts, In the
RECEM position, with the relay de-
energlzed, the tubes that are norhally
used only in tran3mittiDg are cut oft in
the sarne manner. Relay K2, which
when de-energized feeds signals frorn
the output pi-network to the receiver,
and is used also to control any external
switching. In the TRANSMIT po3ition,
the meter indicates the cornbined cathode
current oI the two Power Amplifiers.
In the RECEM po6ition, it indicates the
voltage acro6s R902 in the cathode of the
Second
IF Amplifier, V9, which is
iDversely proportional to the AGC volt-
age used to control the gain of the tube.
Thus the S-Meter reads le{t to right on
transmit, and right to left on receive.
POWER RATING
The Swan 400 is capable of 400 watts,
PEP input under steady two-tone te6t
.onditions, when operated with any of
the recommended power supplies. The
peak envelope power, when voice modu-
lated, i5 considerably more, tyPically
500 \ratts, or rnore,
Recommended power supPlies produce a
no-load plate voltage ol approximately
925 volts. Under TUNE conditions, or
CW operation, this voltage rnay drop to
as Iow as ?20 volts. Under steady state
two-tone modulation, the voltage will
drop to apploxirnately 750 volt3, If Power
Amplifier idling current is 50 rna, and
two tone plate current, ju8t before flat-
topping, is 3?5 ma, the peak two -tone
cullent will be 560 rna. The PEP input
wiu then be ?50 volts x 560 ma = 420 watts,
Under voice modulatio!, beca[rBe average
power i6 considerably Iess' the Pow€r
Amplifier plate and screen voltages will
be mainta)ned hiSher, even during voice
peaks, by the power supply filter capaci-
tors. Peak voice plate cu!rent will thele-
fole also be higher than with two-tone
test conditions. Under typical operatinS
conditions, peak plate current befole
flat-topping will be 625 lna at 800 volts,
to result in a peak envelope power inPut
of 500 watt8.
Reading6 ol cathode current would not
reflect this 500 watt power inPut' how-
ever, because oI the dampiDg in the
cathode current meter. The meter damp-
ing i6 such that the rneter i3 unable to
respond to variations oJ cathode current
in the audible range. Cathode current
readings under normal voice input, should
not exce€d approximately I50 to 175 rna.
POWER AMPLIF]ER PLATE DISSIPATION
There is olten a mi sund€r standing about
the plate dissipation of tubes operated as
AB ampliliers under voice modulation,
In the Swan 400, while in the transmit
position, and with no modulation' the plate
voltage will be 890 vo1te, the plate current
50 rna, and the power input will be 50 watts.

I MODEL 4OOTRANSCEIVER
A, Circuit Theory (Cont)
Authorities agree that the average voice
power is l0 to 20 dbbelow peak
vorce
power. Normally some peak
clipprngin
the Power Amplilier (
anbe tolerated,
and a peak-to-average ratio oJ only 6 db
rray sometimeg
occur. unde! sucha
condition, the average power input will
be 125\ratts, and plate current will be
about 156rna. With an average Po'\r/er
Amplilier efficiency of 55 per cent, plate
dissipation
wilt be 57watts, or 28,
5
watts per tube. The 6HF5 is rated at
28 watt6 continuous duty cycle in normal
TV service. Thus it can be seenthat
under normal operating conditions th€
PA tubes in the Swan 400 are not being
driven very hard. Only dLrring
the tune
up is there any need to exercise caution
by lirniting the length of time the unit is
held in the TUNE position to about 30
seconds
at a time,
B. INSTALLATION
CENERAL
The Swan 400 traogceiver has been
designed to provide the utmost in ease
of operation, stability, versatility, arld
enjoyment. Maximum enjoyment Irorn
your Swan will depend to a great extent
on the installation. For fixed station or
portable use, operation with the Model
I I?XB or I t?XC power supply provides
a ( ompa( t dr rdngement with maxrrnum
ease oI op<ration. AII swrt(hrn8 is
performed in the transceiver. For
mobile installations, the Model l4-I1?
supply provides switching ar rangements,
and speaker output rnay be fed through
the car broadcast receiver 6peaker,
POWER SUPPLY
The Swan Models II?XB or ll?XC power
Eupplies provide aU neces6ary voltages
required by the transceiver. The
supplies corne equipped with a pre-wired
plug and cable, all !eady for plu8ging
into the transceiver, The Model l4-II7
supply lor mobile operation includes all
necessary cables, conn€ctor plug, luses,
and installation hardwa!e. The Jones
plug lor connection to the transcervet ts
furnished with the unit.
8
Power requirements for the Swan 400
are shown in the following table. Pin
connections to the Jones type power
connector are also listed as an aid in
connecting other brands or horne-brew
power eupplies.
+AC or DC
EXTERNAL SPEAKER CONNECTIONS
Audio output from the transceiver is pro-
vided at pin 12 of the Jones plug. The
other speaker lead goes to the common
chassis ground at pin 6. Output impedance
is between 3 and 4 ohms. For mobile
installations, the car broadcast speaker
rnay be used, in ]vhich case a DPDT
Pin Nornrnal Minirnum Maximurn
High
Voltage 8800vDc
5OO
MA 600VDC 1000vDc
lli. Powe r
Mediurn
Voltage t0 z?5vDc
I50MA 225VDC 325 VDC
Bias
Voltage 3-
110vDc
IOOMA -100
vDc -I30
VDC
Filament
Voltage 412.6 Y'N
5.5 alnp. II.5V t4.5v
Relay
Voltage 5r2 VDC
250MA IO
VDC 14.5 VDC

I MODEL 4OO
TRANSCEIVER
B. Installation (Cont)
seLector s\ritch should be installed to
select either the broadcast receiver or
tranaceiver output.
MICROPHONE
The rnicrophone input is designed lor
high impedance rnicrophones only. The
choice oI microphone is imporlant, for
good speech quality, and ehould be given
serious consideration. Th€ crystal
lattice filter in the transceive! provides
all the restriction necessary on audio
response, and fr.rrther restriction in the
microphone is not required. lt is more
irnportant to have a mic rophone with a
smooth, flat response throughout the
speech range. The microPhone PIug
should be a standard l/4 in. diamete!
three-contact type. The tiP connection
is for push-to-talk relay control, the
ring connector is for the microphone
terminal, and the sleeve is for the com-
rnon chassis ground. The manufactu!elis
instructions should be followed in connect-
ing the lnicrophone cable to the Plug.
With many microphone6, the push-to-talk
button rnust be pressed to make the
rnicrophone operative, even though the
panel function switch i5 in the transmit
position. This leatule rnay be disabled,
iJ desired, by opening the microphone
case and permanently connecting the
contacts which control the microPhone.
ANTENNA
Any of the common antenna systems de-
signed for uEe on the high frequency
amateur bands may be used with th€
Swan transceiver, provided the input
impedance of the transmission line is not
outside the capability ol the pi-output
matching network, An antenna which
reflects a standing wave !atio on 50 or
?5 ohm rransmiss;on line, below aPproxi -
matety 4: I at the proposed oPerating fre -
quency, or a system tha! results in a
transmission line iiput impedance that
is essentially resistive and between l5
and 500 ohlns will take power from the
transceiver with little ditficulty. If tuned
open-wire trallslnission line is used to
excite the antenna, a suitable antenna
tuner should be used between the trans -
ceiver and the antenna to Provide a
reasonable irnpedance match between the
unbalanced coaxial output and the balanced
open-wire line. Methods oI constructing
and operating such tuners ale described
in detail in the ARRL Antenna Handbook,
and sihilar publications. Fo! oPeration
on the 75- and 40-meter bands, a simPle
dipole antenna, cut to resonate in the
rnost used poltion oI the band' will Per-
forrn satisfactorily. For operation on
the 10, I5, and 20 meter bands, the
efficiency of the station will be Sreatly
increased if a good di!ectional rotary
antenna is uBed.
MOBILE ANTENNA
Mobrle antenna rnstallations are critical,
since any mobile antenna fo! use on the
high frequency bands repre6enta a num_
ber oI cornpromiBe6. Many alnateurs
Iose the ef{iciency oJ their antenna through
improper tuning. Points to remernber
about the rnobile antenna used with the
Swan 400 are:
I, The rO" o{ the antenna loading coil
BhoIrId be a6 high as possible. There
are several comme rcial models
available which use high "Q" coils,
including the Swan Model 45 and
Model 55 5 band "Swantennas.'
2. The loading coil must be caPable oJ
handling the power of the Model 400
without overheating. In TUNE
position, the power outPut of the
transceiver Inay exceed 250 watts.
wide spaced, heavy wire loading
coils are essential, 9

I MODEL 4OO
TRANSCEIVER
B. Installation (Cont)
3.
4.
The SWR bridge is a useful in6tru-
ment, but unfortunately it is quite
often mis understood and overrated
in importance. Basically, the SWR
bridge wil.l indicate how closely the
antenna load imPedance matches the
transmis sion line, With long
transrnission lines, such as will be
used in many fixed station installa_
tions, :t rs desirable !o keeP tle
impedance match fairly close i.n
order 10limit power loss. This is
particularly true at the higher fre-
quencies. The longer the llne, and
the higher the frequeDcy, the rnore
important SWR becornes, However,
in mobile Installations the trans-
rnission line seldom exceeds 20 feet
in length, and an SWR oI even 4 to I
adds very little to Power loss' The
only time SWR will indicate a low
figure is when the antenna presents
a toad close to 50 ohrns, bot nany
mobile antennas will have a base
impedancc as low as l5 or 20 ohrns
at their !esonant frequencY. In
euch a case, SWR wiU indicate 3
or 4 to I, and yet the system will
be radiating efticiently'
The really important tactor in your
mobile antenna i5 that it shoold be
carefully tuned to resonance at the
desired frequency. The JallacY ln
using an SWR b!idge lie6 in the {act
that it is sometimes Pos
sible to
reduce the SWR readin8 bY detuning
the antenna. Field strength may
actually be reduced in an effort to
bring SWR down, Since tield
strength is the Prirnary Soal' we
recornmend a FieId Strength Meter
Ior antenna tuning.
I'or antenna aajustments, the Swan
400 rnay be loaded lightlY to about
lO0 !na. cathode current in6tead of
the us\ral 500 rna. This wiU limit
tube dis sipation duling adjrstrnents,
and wilt also help reduce interler-
ence on the frequency. In any case,
do not leave the transrnitter on for
very long at one time. Turn it on
just long enough to tune and load,
and get a Jield strength reading.
Start o\rt with the antenna whiP at
about the center of its adjustment
range, Set the VFO to the desired
operating Irequency and then adjust
P. A, TUNc Jor diP, and P. A'
LOAD for I00 ma, Then observe
the tield strength reading. The
Field Strength Meter rnay be set
on top oI the dash, on the hood, or
at an elevated location sorne distance
from the car.
Change the whip length a half inch,
or so, at a time, retune th€ P.A.
for I00 rna. loading each time, and
check field strength. Continue this
proLedurc until the point of maxirnum
Iield strength is found. This adjust-
ment will be Inost critical on 75
rneters, somewhat le66 critical on
40, etc., until on l0 rneters the
adjustment will be quite broad.
AJter tuning the antenna to resonance'
load the P. A. to IuIl Power'
5.
t0

I MODEL 4OOTRANSCE]VER
B. Installatiob (Cont)
CONTROL FUNCT]ONS
Functions of the
ON.OFF
SWITCH
FUNCTION
SWITCH
Standby
Calib!ate
Receive
Transrnit
Tune
Contlols the varioLls
modes of operation
of
the tran6ceiver.
DC Supply - Power to the
transceiver is disabled.
AC Supply - All voltages
except medium voltage
are suPplied.
AC Supply - Plate and
RF CAIN
(In F requency
Control Unit)
MAIN
TUNING
PA GRID
various contlols are as follows:
Controls main po\rer to CARRIER
the transceive !. BALANCE Controls potentiohete!
R1405 in the balanced
modulator defl ection Plate
circuit, and permitg
balancing of the carrier.
Controls variable !esistor
Rl80l which is cornrnon itr
the cathodes of V6, RF
AmpliJie !, V8 l st IF Am -
plifier and V9, znd IF Am-
plifier, controlling gain of
these stages.
Controls potentiomete!
Rl20l in gtid circuit oI
vI2 AF Output, and varies
the gain ot the final audio
output amplifie r,
Controls C
I804 in frequency
deterrnining tank circuit oI
!. !equency Control Unit.
Controls CIA and CIB in
plate tankE of transmitte!
Inix€! and driver.
Controls C4l ? in pi-network
to tune linal power arnpli-
tier plate to resonance.
Controls C420 in pi -network
to match impedance of out-
put load. TuneE input to
Receiver RF Arnplifi€ r.
Switches in progres sively
more capacitance in Paral-
lel with PA Load, Fine.
Switche 6, plate coi1s, and
associated caPacitors of
VFO Amplifier, VI, Tran8 -
mitter Mixer, V2, and Dri-
ver, V3, Also switches
tank coil of pi-coupling
system and associated
capacitor s in PA outPut
ll
scleen voltage are aPPlied AF GAIN
to Vl3, DC Supply - 12
volts dc is provided to the
relay ci !cuit, high and
mediurn voltages supPlied
to the plate circuits and
bias voltage is proviced
to the relay controlled
Same a6 for Calibrate
but voltaSe to Vl3 re-
12 volt dc circuit through
relay Kl and KZ i3 corn-
pleted, and all tubes us€d
only in rec€ive are
biased to cutoJf.
AII circuits for transmit
are energized, as above,
but only deflection plate
of the balanced modula-
tor is grounded, capaci
-
tor C1504 in the carrier
oscillator ie removed
frorn ground, C1503 is
grounded.
Control6 potentiometer
R1603 in the grid Vl68
and controls amount o{
audio to the balanced
modulato r.
PA TUNE
PA LOAD,
r.ine
PA LOAD,
Coarse
MAIN
BANDSWITCH
MICROPHONE
GAIN

M.DEL4oor^lo*r"rrut*
ll C. OPERATION
WARNING
DANGEROUS ruGH VOLTAGE IS
PRESENT ON THE PLATE OF THE
POWER AMPLIFIER WHENEVER
THE POWER SUPPLY IS ENER.
GIZED. NEVER TURN POWER ON
WHEN THE POWER AMPLIFIER
COVER IS REMOVED. HIGH VOLT-
ACE IS ALSO PRESENT AT PIN
EIGHT OF TIIE POWER PLUG.
The Swan Model 400 may be operated
with either the Model 4068 or Model
410 I.requency Control Unit, and may be
operated lrom lI7 volts, ac, 50 to 60
cycle power with the Model I l?XB powe!
6upply or the Model Il?XC powe! eupply.
The Model 400 may be operated flom a
12,6 volt dc source with the Swan
Model l4-l l? power supply.
Before connecting any cableE to the
Swan 400, perforrn th€ foilowing stepB:
l Rotate the PA Bias control on the
rear chassis apron, fuUy counter
cloc kwi s
e.
2. Rotate the Function Switch located
on the lower IeJt of the front panel
counter clockwi6e to STBY.
3. Rotate the AF Gain Control countei
clockwise to operate the power
switch to OFF.
POWER SUPPLY AND
ANTENNA CONNEC TIONS
l. Connect either the Swan 4068 or
410 Frequency Control Unit to the
9 pin connector near the center of
the rear chassis apron.
2. Connect a 50 to 75 ohln antenna to
the coaxial connector on the rear
chassis pane1.
3. Connect the power supply cable to
the Jones connector on the rear
chassis apron.
t2
4. Connect the power supply to the
proper voltaSe solrlce.
RECEIVE OPERATION
L Rotate the AF Gain Control clock -
wise to about the 3 orclock poBition.
The po*er switch will opelate
applying filament, relay, bias, and
800 volt high voltage to the tran8-
2. Wait approximately one minute to
allow the tube filaments to reach
operating lernperatu!e. DurinB
this period, perlorm the followrng
steps:
(a) Rotate the Sideband Selector to
the c
ounter -clockwise position,
providing lower sideband on 40
and 80 meters. and uDDer side-
band olr 20, 15, and I0 meters.
The oppo6ite 6ideband will be
selected when the 6witch is in
the clockwise position,
(b) Rotate the Phone-CW switch to
Phone,
(c) Rotate the Bandswitch to desired
band.
(d) Rotate Mic. Gain fully counter-
clockwis e.
(e) Rotate Car. Bal. control to the
midscale position, with \rhite
dot on knob aligned with the
rndex mark on the panel.
(f) Preset PA Plate control to
rnid-position.
(g) Pre set PA
posrrlon,
(h) Preset PA
po
sition,
Glid Control to rnid-
Load Fine to rnid-

1MODEL 4OOTRANSCEIVER
C. Operation(Cont)
(i) Rotate PA Load Coarse to
position 6.
(j ) Rotate Bandswitch on Fre -
quency Control Unit to
desired band,
(k) Set !'requency Control Unit
tuning dial to desired operat-
ing f!equency.
(l ) Set R!. Gain Contlol to
approximately 3 o'clock
position.
3. Rotate the Function Switch clock-
wise to the REC position.
4. Care{ully adju6t the PA Glid and
th€ PA Plate controls for maxi-
rnudr receive! noi3e. Note: The
PA Grid Control resonates the
transmitter driver stages and the
receive! RF amplifie! plate cilcuit.
The PA Plate ard PA Load con-
trols adjust the input and output
capacitors in the transmitter power
arnplifier final plate circuit, as
well as the receiver RF ahplilier
grid circuit. Prope r adju6tment
of these controls in the receive
position will re6ult in approximately
resonant conditions in the trans-
rnitter stage6.
RECEIVER TUNING - IMPORTANT,
READ CAREFULLY.
Precise tuning of a Bingle Bideband
signal is very important. Do not be
€atisfied to merely tune unti.lthe voice
can be understood, but take the extra
care of settiDg the dial to the exact
€pot where the voice sounds natural.
Above all, avoid the habit of tuning so
that the voice is pitched higher than
norrnal. This is an untortunate habit
practiced by quite a nuhber ot oPera-
tois, The following points help to
explain the effects o{ rnistuning:
I. If you tune so the received voice 1s
higher than normal pitch, you will
then transmit ofI frequency, and
your Yirce will sound lower than
nor't[.] pitch to the other station,
He wlll probably retune hi8 dial to
mak€ /,rrr sound right. If fou keep
this up, you'Il gladoally waltz one
another across the band, If both
of you are rnistuning to an unnatural
higher pitch, your11waltz across the
band twice as fast. (And someone
will no doubt be accused of fre-
quency drift),
2. Mistuniog !esult€ in serious har-
. monic distortion on the voice, and
ghould be quite noticeable to the
average ear. Some will claim that
if they donrt know how the other
personrs voice actually sounds, they
canrt tune hiln in propelly, but this
i6 not true. With a little practice,
it wiU be Iailly easy to tell. Sorne
voices are relatively rich in ha.-
monics, and ale easier to tune iD
rhan a person v,/itha r'Ilat" voice.
AIso, a transmitter \rhich is being
operated properly with low diBtor-
tion will be eaEier to tune in than
one which i€ being over-driven and
is generating excessive distortion,
There is no lnistaking when you
have a station tuned right on the
nose, It wil.l sound ju6t like I'AM, r'
so to speak. Mainly, avoid the
habit of tuning 6o everyone sounds
higher than rormal pitch, or like
Donald Duck. This i6 incorrect,
unneceaaary and sounds terrible.
3. A vernier control for receive fre-
quency, sometime6 reterred to as
!'incremental tuning,rt is not avail-
able on the S\ran 400. Such a device
is not necessary if proper tuning
habits are exercised. t3

I MODEL 4OO
TRANSCEIVER
C. Ope
ration {Cont)
4. Your Swan 400 will automatic ally
transmit on exactly the same {!e-
quency as the one to which you are
Iistening. There is no adjustment
Jor rnaking them the sarne, since,
by using the 6alne oscillato! for
both send and receive, it happens
automatically. If separation of re-
ceive and transmit frequency con-
trol is desired, the Model 22 dual
VFO adaptor rnay be installed in
the VFO socket on back of the 400,
and a pair of 410's
or 4068's may
then be p)ugged into lhe adaptor'
CALIBRATE
To calibrate the Model 410 Frequency
Control Unit dial, tollow these four
steps:
l. Rotate the function switch to CAL.
Z, Rotate th€ Kilocycles dial to the
100 kc increment neare6t the
d€
sired operating frequency.
3, An audio beat note will be heard
in the 6peaker.
4, Adjust the Dial Set knob for zero
TRANSMITTER TUNING
Tuning of the transmitter is not com-
plicated, providing the lew simPle steps
are followed in the co!rect order. Do
not attempt ini.tial tuneup without first
performing the ptocedures for Receive
operation described above. The louow-
ing procedures assurne that the unit has
been checked out in Receive Position,
and that the powe! suPPIy and Frequency
Codtrol Unit are adjrsted and oPerating
properly.
t. Rotate the Fonction S]vitch to
TRANSMIT, read the cathode
current on the front Pane1meter.
l4
Ouickly rotate the CAR BAL con-
trol on the lront Panel until the
mete! reads rninimurn cathode
Next, adjust the PA Bias control on
the rear ol the chassis until the
mete! reads 50 !na.
3.
4. If thi€ is the first time the trans-
ceiver is being tuned on this band,
set the PA LOAD switch to Position
l. Afte! experience ir tuning uP,
the control rnay be set to whatever
po6ition has been found to be
optimum on each respective band.
Now, in rapid succession:
(a) Turn the CAR. BAL. control
clockwise until a 51i8ht increase
in meter reading is obtained.
(b) Rotate the PA GRID control for
maximurn meter !eading.
(c) Rotate the PA PLATE control
for minimurn meter leading.
(d) Adjust car. bal. for a leading
oI 150 rna.
IMPORTANT - Tuning the PA PLATE
for minimum, or "dip, " i3 known ag
i
resonatingri the power amplifiel
plate circuit, and i3 vety ilnportant
to preserving tube life. If the
transceive! is held in Tran8rnit or
TUNE position for more than a few
seconds while out of resonance and
with sorne glid drive, the 6HF5
tubes rnay be severely damaged.
For this reason we tepeat: CAUTION -
Do not hold the transceiver in Trans-
mit or TUNE position for any length
of time without rrdiPPingri the PA
PLATE control. The PA GRID rnust
first be Ipeakedrr as in (b), above,
and this requires some carrier
supplied as described in (a), so it
can be seen that these stePs rnust be
p€rformed quicklY. If the PA LOAI)
control is too far clockwise, it lnay

I MODEL 4OOTRANSCEIVER
C. Operation (C
ont)
not be possible to find arrdip| with
the PA PLATE control. r.or this
reason, be sure to ob6erve the first
sentence in this section, Step 4.
5, Rotate the REC. TUNE switch to
TUNE position. Ouickly check the
PA PLATE control for |dip| o!
minimom leading. If the meter
dips to lesB than 500 ma,, inclease
loading by rotating the PA I.OAD
controls clockwise, After each in-
crease in PA LOAD, resonate the
PA PLATE again; that is, adjust it
for dip. Continue increasing PA
LOAD until the PA PLATE dips to
450-500 ma. Then switch back to
RECEIVE.
CAUTION: Do lrot hold the tlans-
ceiver in TUNE position Jor more
than 30 seconds at a time, even
though PA PLATE is re€onated,
With fuu grid drive to the 6H!'5 PA
tubes, which you have in TUNE
position, they are dis6ipating
con8iderably more powe! than they
do durinB normal voice transrnis-
sion, 60 a short tuning period lnu6t
be observed-
A--,4.,.1t*La''.a?,:!a,a;aa'.-J.aI.A
aLLI.L.. /^ l. .-..2 o '.I -4,
6. Under some conditions, it may nor
be possible to load up to 500 ma,
This fnay occur with lowe! than
norhal line voltage or tubes not
quite up to par, particularly on l0
rneteis, The curlent increase when
tuning the plate circuit ofl resonance
will provide a clue as to how {ar the
power ampli{ier can be loaded. Il
the meter s\rings up to 600 or ?00
ma. on either side of resonance, it
will be easy to load up to 500 or even
more, But, if the tubes dra\r ju6t
500 ma. off resonance, you can only
load to 400 or 450 rna. This is not
necessarily a sign that you have a
problem, Peak input power with
voice modulation will still be 400
watts whenyou load lo 400
ma. in
TUNE position. A new pair of PA
tubes may allow yor.1to Loadhigher,
o! possibly a new drivet tube will
help. Plirnalily, the level to which
you can load will serve as an indica-
tion of when tubes are deteriorating.
If you can load to 500 ma. when the
set is new, and after a few monthg
of operating you cannot get above
400ma., or so, it is plobably time
to leplace the 6HF5 tubes, and
possibly tbe 6GK6 driver. The other
tubes should also be checked at that
time.
AVERAGE PA LOAD SWITCH POSI-
TIONS. The {oUowinS po6itionB are
{or a 50 ohrn non-inductive load,
and indicate approximately lphere
the PA LOAD srritch will end if the
antenna and coaxial cable are well
matched.
BAND PA LOAD SWITCH
'7.
80
40
20
IO
POS. 7
8
9
9
l0
A large deviation from theBe po6ition8
indicates a possible matching problem,
althouSh operation may 6till be quite
Batisfactory. PA LOAD switch posi-
tions below 5 will generauy be
neededonly with very low impedance
loadB, such as a 75 rneter rnobile
antenna with center loading coil.
VOICE TRANSMISSION. After tuning
up as outlined above, piess the Push-
to-Talk buttonon the mike and care-
fully set the CAR, BAL. control for
minirnum meter readin8, While
speaking into the mike, slowly rotate
7.

I MODEL 4OOTRANSCEIVER
C, Operation (Cont)
the MIC. GAIN control until occa-
sional peak reading oI l?5 to 200
ma. are obtained. With most
rnicrophones, the MIC. GAIN con-
trol will be set between 9 and l2
orclock, but it rnay vary consider-
abry. The ALC circuit will help
limit cathode current to about 200
rna., but turning the MIC. GAIN
{rp too high will still produce flat-
topping and 6purious siBnals, so it
is important to hold it down. The
meter is quite heavily damped, and
its reading *ith average voice modu-
lation may nol look very impressive,
but the voice peak6 are going well
ower the 400 $att Po\"er rating of
your Swan tlan6ceiver, and signal
reports will verify this fa(t.
8. TRANSMITTER TUNING WITH
SWR BRIDGE OR FIELD STRENGTH
METER. lf either oI the6e instru-
ments is available, they are highly
recommended as a better method o{
tuning the PA AmpliJier, since they
provide a direct indication of rela-
tive output. With the SWR Bridge
in Forward position, or with the
Fie]d Strength Meter 5et to pick up
a portion of the radiated power,
simply adjust the PA TUNE and PA
LOAD controls for rnaxirnurn output.
This rnust be done quickly, limited
to about 30 seconds, to limit tube
di6sipation as previously mentioned.
This method will result in rrraxr-
lnum possible output and efficiency,
as well as rnaxirnum linearity. You
witl probably find that cathode
current readings end uP somewhat
less than 500 ma. on l0 meters
becau6e grid drive is the least on
this band. On 80 rneters where grid
drive i6 the greatest, rnaxinurn out-
put will be reached at rnore than
500 rna. These are a normal condi-
tion.
16
NOTE - The cathode cur.ent level
to which the PA is loaded will have
no bealing on tube life, When
transmitting with nolrnal voice modu_
lation, average Povwer
inPut rrill be
the sarne regardless of how high or
1owthe PA was loaded while tuning.
Peak output, Iinearity, and lowe8t
distortion will go along with maxi-
mum loading. In other words, You
will not extend tube life by loading
to a lesser degree, The secret to
long tobe life is simply to keep
TUNE-up periods short and not too
frequent.
AM OPERATION
(Single
Sideband
with Carrier)
L Tuneup transmitter to full output
on single sidebandon desired fre-
quency band as described above,
2, Rotate MIC GAIN contlol to lull
counter-clockwiae
Position.
3. With Function Switch in TRANSMIT,
rotate CAR BAL control until
cathodecurrent rs apptoximately
150ma.
4. While talking in a nollnal tone oI
vorceinto the rnicrophone, increa6e
MIC GAIN setting until variation is
just discernible on meter. This
setting will result in adequatehodu-
lation with one sideband.
CW OPERATION
l. Tune transmitter to firll output a6
described
above.
2. Insert CW key in the key iack Pro-
vided on the back of the 400. Use
a standard I/4 inch diamete! 2
circuit phone plL1g.

1MODEL 4OOTRANSCEIVER
C, Operation (Cont)
3.
4.
Add a .4T or . 5MF. , 200volt
caPacitor across the key. This
capacitor rnay be added internally
if desired,
Switch the PHONE -CW control owe!
to CW position. Then switch the
Function Switch to TRANS. to
transmit, and REC. to receive.
5. In{ormation on a sidetone modifi-
cation for the 400 iB available on
request.
GENERAL
The following proceduies are given in
the order performed during the factory
alignrnent fo! the transceiver, For
home servicing only partial alignment
may be necessary. Read all procedures
carefully before commenc ing either
partial or complete aliSnment. See
Figures 4 and 5Ior component place-
rnent.
Equiplnent Requi!ed
L Caliblated audio freqqency signal
generator, range 200 to 5000 cps.
2. 500 watt dummy load with output
3. Vacuum tube voltmeter,
4, Walsco 2543 coil adjustbent tool.
5, Field str€ngth meter
6. Calibrated RF Signal Generator.
P!e -Alignment Conditions
l. Neutralizing capacitorB C4l3 aet
to rnid-point and C3l6 Bet to
approxirnately 3/4 turn lrom futl
cornpres 6ion.
2. Peak lF transformers for maxi-
rnurn background noise with AF and
RF gain Iull clockwi8e (eithe!
bottom or top core adjustrnent).
3, Loosely, couple field strength
rn€ter to C3l? (off pin 9 of V4)
with alligator clip on cerahlc
capacitor body.
TROUBLESHOOTING
4. Transmit bias potentiometer full
counter-clockwise (maximurn bias).
VFO AMPLIFIER PLATE
CIRCUIT ALIGNMENT
With VTVM from pin I of V7, Receiver
Mixer, to ground, on -15 volt scale,
and using a Model 410 or 4068 Frequency
Control Unit, adjust Vr'O Amplifier
Plate coils {or peak VTVM heading as
followB:
D. ALIGNMENT AND
Band VFO Fle -VFO Dial
Reading
Frequency(kc) Coil
80 3,800 Lt 04
40 12,300 7,125 L103
l5 r6,050 Lt0z
lo 28,500 Ll0l
TRANSMITTER MIXER AND DRIVER
PLN,TE CIRCUIT ALIGNME NT
1,. Rernove screen voltage florn V4 and
V5 by disconnecting orange wire to
telrninal strip irnrnediately adjacent
to V5 baBe. (Pt. A in Fig. 5.
)
2. ConnectVTVM across P.412,4.7K
resistor bet$/een
pins I and 2 of
terminal strip irnmediately behind
bifilar coil in cry6tal filter, !ange
-I5 volt scale, (Points B andC in
Fig.5). t7

I MODEL 4OO
TRANSCEIVER
FIGURE
4
[-a.f
TOP VIEW, MODEL 400 TRANSCIEVER.
18
FIGURE5 BOTTOM VIEW, MODEL 400TRANSCEIVER

I MODEL 4OO
TRANSCEIVER
D, Alignment and Troubleshooting (Cont)
3. Set PA grid tuning Iully clockwise,
phone
-cw switch in Phone
Position,
sideband selector in USB Position.
Procedure:
Adjust bandswitch to band shown and
adjust coils for PeakVTVM !eading as
follows:
Function
Switch Band
vFo
Freq,
(t.) Adjust
Tune* 80 4,O25 LZO', L305,
cI507, zL40l
Tune 40 7,
350 L204, L304
Tune zo r4,500LZ03, L303
Tune 21,500LZ|Z, L30Z
Tune IO 29,?00L20r, !301
* Note: I{ VTVM and field strength meter
exceed ful1 scale readinS, gwitch to
transmit posltronand
insert carrier
with carrie! balance control to keep
reading on scale. Fietd Btlength meter
and VTVM must both Peak at same time
since it is possible to t|.1ne
the coils to
the VFO lrequency on l0 meters. Care
rnust be taken that the coils be hrned
pro pe rly.
Following the above Procedures, replace
orange wire to Pin I of terminal slriP
adjac ent to V5.
ALIGNMENT OF 5T?5 KC
TILTER TRAP
With RF and AF gain at midscale, feed
5I?5kc signaf to antenna connector and
adj\rst L60Z until heterodyne di€aPPea!8
o! S
-meter reads zero'
ADJUSTMENT OT CARR]ER
FREOUENCY
A. With dummy load and outPut meter
attached, tun€ transceiver for lnaxi-
rnurn otrtput.
B. Null out carrier with PTT Pressed
and set reBting Plate current to 50
ma wlth bias Pot.
C, Connect AF generator to MIC JACK '
adjust MIC, GAIN full CCW-
Proced|1!e:
With AF generator at 1500
cP3,
increaee
MIC. CAIN to P!oduce
a
100ma, reading on the meter.
Adjust 2801 for rnaxirnuln meter
reading.
L
z.
3. Adjust both toP andbottom corea of
Zl40l for maxirnlrm rnetei reading.
4. Adjust MIC. GAIN for t'teter read-
ing of 300 rna.
5. SetAF generator to 300
cPs. Adjust
C1507
Ior meter reading
of 75 ma.
6. Repeat stePs I through 5 for USB
operation, adju6ting
C1506.
PA NEUTRALIZATION
With P.A. coatse load in po6ition I, set
{req. to 14.150, PA Plate control at 9
orclock, insert carrier and
peakP. A.
Crid control, adj\rsting Car. Bal. con-
trol for 200 MA, Turn PA control
slowly thlough iesonance. Cathode
current should diP srnoothly and rise to
2OOMA on the 1oll caPacitY side of
re6onance. If, instead, there i6 a peak
above ZOO
MA either side of the dlP'
stop rotation of the PA plate control at
t9