Hy-Gain Afterburner 419 Installation instructions

. AFTERBURNER
ORDER NO.
419
MOBILE STATION 12V DC
BI LATERAL LINEAR AMPLIFIER
INST ll TION
OPER TION INSTRUCTIONS
AFTERBURNER
RuraI Route 3
Lincoln. Nebraska 68505
This Bi-Lateral Amplifier is precision built, compact amplifier of
advanced design. It utilizes an integrated circuit, two tubes, four
transistors and four diodes and a grounded grid, tuned plate
circuit for amplication for AM, FM, CW, and SSB signals in the
25-54 MHz range.
A special feature of the Amplifier is the automatic antenna
change over relay which operates without special external
connections making it perfect for operation with low power
transceivers not having external amplifier control circuits.
Another feature is that this unit amplifies the received signal,uti-
lizing an integrated circuit amplifier.
Variable plate tune and load capacitors offer impedance matching
for maximum output to varying antenna loads in the 40-70 ohm
range.
~The Bi-Lateral Amplifier has been designed and constructed to
suppress radiation that may cause television interference. TVI
problem has been given full consideration in design and layout of
the chassis.
There are, however, some types of TVI that cannot be prevented
within the amplifier. This is particularly true in weak signal areas.
In such cases, a good commercial low pass filter is recommended.
Height 4 1/8
Width 7 1/8
Depth 103/8
Net Weight 5 Lbs.
Shipping Weight 8 Lbs.
Construction Lightweight aluminum chassis
with rugged steel case
Power Requirement +12-14V DC
15 Amp
Frequency Range 25-54 MHz
Types of Emission AM, FM, CW, SSB,DSB
Power Output (Slightly less at 50 MHZ) 220 Watts
PEP, SSB, or DSB
.~ 100 Watts (with 3.5 watts drive)
Amplification of Received Signal 20 db
Drive Requirement to Trigger Antenna Relay 1 Watt
Max Drive (unmodulated carrier) 15 Watts
Odd Order Distortion Products 30 db below peak output
Harmonic Suppression 2nd Harmonic at least
35 db below peak output
Input Impedance (unbalanced) 50 Ohms
nominal, less than 2: 1 VSWR 25-54 MHz
Output Impedance (unbalanced) 50 Ohms
nominal, Adjustable 40-70 ohms, nonreactive
Antenna Switching Automatic provided by
RF sensing network
Tube and Diode Complement 2 Tubes
4 Transistors, 4 Diodes
1 Integrated Circuit
Cable Connector Data Input and Output
require MIL PL-259
() Carefully remove the amplifier from the packing carton.
EX::lmineit closely for signs of shipping damage. Remove the four
screws holding the top cabinet and remove all hold-down tape
and packing materials. Check to insure tubes are seated in the
sockets. Install the plate caps on the tubes and the fuse in the
holder. Inspect for any signs of internal damage.
The unit is made to operate on negative ground systems
only. Do not attempt to operate your amplifier until you have
read the manual and properly installed t he unit.
() The location is' not critical but consideration must be given to
adequate ventilation.
IMPORTANT
Allow at least 4 of clearance on all sides of the cabinet
for good air circulation.
() The primary power connection on the amplifier is the +12V
DC terminal on the rear panel.
() The fuse holder is provided on the hookup cable with a 20
amp fuse. Do not use a larger capacity fuse or amplifier,
transformer, and power supply will not be protected.
() The unit will not operate without grounding. It is
recommended that a No. 12 or heavier wire be run from the
ground terminal on the amplifier to the ground terminal on the
battery.
() The bi-Iateral amplifier will work with the common antenna
systems designed for the 25-54 MHz range provided the antenna
has a resistive input impedance between 40-70 Ohms. The SWR
should be kept to a minimum of 2:1 or less.
() The output connector provided is an So-239. For connection
of your antenna, you will need a PL-259 plug.
ON-OFF Switch Controls +12V DC power to amplifier
AM-FM &SSB Switch Adjust delay constant of automatic
antenna relay

XMT-Standby Switch .... Activates the automatic antenna relay
circu it, also suppliespower to the receive
amplifier circu it.
ReceiveAmplifier ON-Off Switch Activates the integrated
circuit receiveamplifier.
NOTE: Receiveamplifier will only operate when theXMT-Standby.
switch is in the XMT position and the REC AMP switch is ON.
RED Indicator Light , Visual indication of applied
+12V DC power
Output Meter Visual indication of relative
RF power output.
Tune Knob Adjusts resonant frequency of amplifier.
Load Knob Adjusts coupling of output circuit to antenna.
The amplifier can be mounted either under the dash using the
bracket provided or in the trunk asdesired.
When the unit is dash mounted, a fused primary connection to
the battery or fuse block must be provided.
If tru nk mounted, a remote switch must be used, and can be
purchased through your local dealer. Mount the remote switch on
the dashwhere it isconvenient. Remote switch mounting must be
grounded to the vehicle chassis or the indicator light will be
inoperative.
Remember the front panel and remote switches are series
connected. The ampl ifier wi II not operate if either switch
is in the OFF position.
Before beginning installation it is recommended that the
positive lead of the battery be disconnected to prevent ac-
cidental grounds and electrical system damage.
Connect the fuse hookup cable to the positive terminal of the
battery or fuse block. The other lead should run under the seats
and carpets in the protected location to the amplifier primary
power connection. A length of RG 58/U should be installed
between the transceiver and amplifier. Connect a nominal 50 ohm
antenna to the amplifier.
Connect the ground stud on the amplifier to the negative battery
connection.
Before applying power, make one final check on all wiring and
connections.
Before applying any RF power to the Linear, pretune the tune
control knob to the desired frequency at which you wish to
operate. See illustration on this page.
For example, if your desired operating frequency is 28 MHz
then set the tune knob at midpoint between 26 and 30 as
shown.
22
•
For operation on the 50 to 54 MHz band set tune control to
the 30 MHz position as shown above. Then refer to the 50
to 54 MHz Operation.
It is assumed that the bi-Iateral amplifier has been properly
installed as called for above. Make sure that all the various
connections have been made.
The following paragraphs are intended to provide the operator
with the basic knowledge needed to operate the amplifier at
maximum performance.
This amplifier must be used with a transmitter or transceiv~
capable of at least one watt output, in the 25-54 MHz range.
First place the function switch in the AM-FM position. Set the
tune control in accordance with the warning onthis pageof the
manual. The load control should be positioned so that the
capa'titor is fully meshed, (dot on knob will then point to the
word load on the front panel).
Now push the ON-OFF switch to ON. The red visual indicator
light will light.
After warm-up, push the XMT-Standby to XMT. This will
energize the automatic antenna relay control circuitry, and
provide power for the integrated circuit receive amplifier.
Apply drive power by keying the exciter (transceiver)
microphone and quickly adjust the tune control for maximum
reading on the output meter. Remove drive power after
adjustment.
Do not apply drive power for more than five seconds without
adjusting the tune control or damage to the tubes can result.
Reapply drive power and advance (clockwise) the load contr~
note the increase in reading of the output meter. Adjust the hi
control for maximum reading of the output meter. Now go bacR--
to the tune control and reset for maximum output. Remove drive
power.

Readjustment of the tuning and loading controls several
times will produce maximum output.
· '-'\rovide for the extra power contained in the AM signal
mudulation it is necessary to overcouple the output circuit.
This is necessary to insure an undistorted output with a minimum
of adjacent channel bleeding (spatter).
Reapply drive power and advance the load control until the
output meter drops perceptably, (about 15 per cent more
rotation). Readjust the tune control for maximum output. The
output circuit is now overcoupled .
If a relative power output indicator is available (SWR bridge on
forward, etc.) the output signal can be quickly checked to insure
upward modulation. If the meter does not flick upward on
voice peaks, the load control is improperly set (or the exciter is
not capable of 100 per cent modulation or may have downward
modulation ). Also seen on output meter.
Automatic antenna change over and ampl ifier operation is
provided for by a special transistorized input sensing circu it.
Should you desire to hold the amplifier in a ready condition,
but not use it until needed, simply place the XMT-Standby in the
standby position. The sensing circuit will be disabled and the
antenna connected to the exciter (transceiver) at all times.
With the XMT-Standby switch in the standby pOSitIOn, the
REC AMP switch should be in the OFF position. This will
prevent the receive amplifier loading the transceiver output.
The amplifier is tuned for FM service in a manner identical to AM
except the load and tune controls are set for maximum output.
Place the function switch in the SSB position. This will connect a
delay circu it to the automatic relay control and extend the
drop-out approximately one second. This will prevent relay
chattering and erratic operation.
If the exciter (transceiver) is capable of carrier output equal to
the peak power of the voice SSB or DSB signal, simply adjust the
tune and load controls for maximum deflection of the output
meter while applying carrier.
If the exciter (transceiver) cannot supply a carrier equal to the
peak power of the voice SSB or DSB signal then the tune and
load controls must be set for maximum output while modulating.
In this case, a modulation envelope indicator (monitor scope) is
the most reliable method for adjustment of the amplifier.
The delay circuit for SSB prevents drop-out of the automatic
antenna relay between characters.
For operation on the six meter amateur band It IS necessary to
short out four turns from the left hand side as viewed from the
front panel of the Pi-network output coii, L1. The 100pf silver
mica capacitor across C17 load capacitor, must be removed. Also
remove capacitor C7, 50pf disc ceram ic located across the input
socket of the rear panel.
REMOVE FOR b METER
AMATEUR BAND
OPERATION
IOOpf CAPACITOR
ACCFiOSS C-17
A portion of the incoming circuit is coupled to the base of 01
sensing transistor. Th is causes 01 to conduct and change the bias
on 02, relay transistor. 02 conducts heavily and closes relay K1.
Relay K1 connects the input signal tQ the cathodes of V1 and V2,
applies plate voltage to V1 and V2, and connects the output
circuit to the antenna.
C18 is the Pi-net tune capacitor and sets the operating frequency
of the amplifier.
C17 is the Pi-net load capacitor and controls the coupling to the
antenna.
For SSB operation, C22 is added to the relay transistor circuit to
extend the drop out time.
An integrated circuit amplifier increases the level of the incoming
signals from the antenna before it is applied to the transceiver.
This amplifier is powered by the XlVlT-Standby switch and the
REC AMP switch. With the XMT-Standby switch in the XMT
position the receive amplifier can be switched ON or OFF as
required. With the switch in the standby position, the receive
amplifier is disabled and the receive amplifier switch should be in
the OFF position (see important note ).

SYMBOL DESCRIPTION SYMBOL DESCRIPTION
C1 150
M
.-«F 1KY DISC CERAMIC Q3-4 2 N 1522 TRANSISTOR
C2,4,5,8,28,20 220Q.,AF1KY DISC CERAMIC Rl-2 270 K.a.1W RESISTOR
C9 5~F 1KY DISC CERAMIC R3 51O.a.1/4W RESISTOR
C13 2Q..y....F1KY DISC CERAMIC R4 1200.4 1/4W RESISTOR
C10, 11 lO.-«F SOOWYDC ELECTROLYTIC R5 330.n.1/2W RESISTOR
C26 10Q.«F 25 WYDC ELECTROLYTIC R6 270.n.1/4W RESISTOR
C23, 24 6800PAF 1KY DISC CERAMIC R7, R13 33~ 1/4W RESISTOR
C14 100QuAF 1KY DISC CERAMIC R8 50.n.10W WIRfWOUND RESISTOR
C19, 15 3300~F 3KY DISC CERAMIC R9 3.a.8W WIREWOUND RESISTOR
C16 .01.,MF 1KY DISCCERAMIC RFC3 CHOKE ~144
C17 lO.5-313.9,uAF AIR YARIABLE RFC 2 47,u/,CHOKE
C18 3.2-50~F AIR YARIABLE C7 50
pf lKY DISC CERAMIC
C21, 25 lQ,t{F 25-35Y DC ELECTROLYTIC RFC4 OHMITE ~-28
C22 500..-'(F 15WYDC ELECTROLYTIC S1,4 DPSTSWITCH
C27 100A.iAF lKY SllYER MICA S2-3 SPSTSWITCH
Dl,2,3,4 IN 5054 DIODE Tl 12Y TO 800Y TOROID
05-6 IN 270 DIODE Yl-2 6JU6 VACUUM TUBE
D7 1N753 ~E NER DIODE 1 C 1 MC 1550GIC AMPLIFIER
Fl SFE 20 AMP FUSE C3 100
pf
lKY DISC
Kl 3PDT 12Y DC RELAY 08 lN34 DIODE
K2 lPDT 12Y DC RELAY RFC 1 100 ,h CHOKE
L1 TANK COIL Rl0 1.2K 1/4W RESISTOR
L2-3 .56-'th COIL R11 10K 1/2W RESISTOR
Nl 14Y BULB #53 R12 4.7K 1/2W RESISTOR
Ql MPS 6516 TRANSISTOR Ml METERRELATlYE POWER
Q2 2N696 TRANSISTOR C29 10~ F 25Y DC CAPACITOR
,~
FI -----6
rc:n-- 12 VOLT
1.. TERMINAL
JV DC