RF Concepts RFC 4-110 User manual

HF fiE[IfiETTS
HFI 4-11n
44[ MHU
FEWEH AMFTIFIEH

RFC 4-1rO
Thank you for buying the RF coNcEPTS RFC 4-116. This
amplifier represents the "fourth generation" of solid state power
amptitiers buitt for amateurs. The RfC 4-110 features a "state of
the art" GaAs-Fet preamp, variable SSB delay, "High SWR"
protectiOn, over temperature prOtection, automatic or remote
keying and remote control capabilities. The RFC 4-IIO is designed
to work with aII modes of transmissions including, FM, CW, and
SSB.
SPECIFICATIONS
Frequency Range ..:..
Power .....
Maximum Input
Duty Cycle
Modes ..... ..... .........
GaAs-Fet Preamp
SWR Protection ...............
Temperature Protection ... o.
Keying
I nput-Output Impedance
Voltage Requirement
Current Requirement
Fuse
Size .....
Weight
*output may vary by .75 db
434-456 MIlz
Input range z 2AA mw to 15 w
Output* t LA6 W with 1O w in
15 Watts
Intermittent
FM, SSB, and
Noise Figure:
Gain 3
Automatic shut
approximateJ-y
175 degrees F
1. Automatic - RF sensing
2. External - Ground or PIus
3-L2 Vdc at J3 - user
option - unit supplied
with "plus voltage" keYing
5O Ohms
13.8 VDC
22 Amps
35 Amp
lf,5x6x3inches
5 lbs
cw
2 to 3db
12db nominal
down with
3:l SWR
WARNING
The RFC 4-IIO was designed to work with radios having 15
Watts maximum output. If your radio puts out more than 15 Watts
you should use an RF CONCEPTS RFC 4-3LA which is designed for a
higher input power.
High power output also means high heatsink temperatures.
Keep ttre heatsink clear of any obstructions and provide adequate
ventilation.

INSTALLATION
The RFC 4-LLg can be mounted with ttre 'Lrr brackets, supplied.
It should be placed to provide maximum ventilation around the heat
sink. Heavy gauge wire should be used to connect the RFC A'LLA to
the battery or power suppty. For medium distances use #IO wire and
for longer distances use #B wire. To connect the amplifier to the
antenna, RG-8A/U or equivelent coax is recontmended.
For best performance, the antenna should be adjusted for an
SWR of less than 1.5:1.
OPERATION
The power amplifier is connected between the radio and the
antenna, The RFC 4-110 will boost the power of a l0 watt radio to
LQA Ylai--ts or more. The GaAs-Fet receiver Preamp wiII improve coPy
on weak or marginal signals. When either the power amplifier or
the preamp are "on" they automatically switch in and out of the
circuit, by sensing the RF from the radio. The rrTxrr LED will
light during transmit.
The automatic switching is ok for FM, but on SSB the relays
may drop out during pauses. Therefore, it is high1y recommended
that the external keying feature be used with SSB. Please see the
"EXTERNAL KEYING" section.
FAULT CONDITIONS
During normal operation the 'TXrr LED will light when the
power amplifier is activated.
The RFC 4-110 has a special circuit that senses return power
(SWR) from the antenna. If this returned power exceeds
approximately 25 Watts, the amptifier automatically shuts off,
lighting the "SWR" LED and turning off the r'Txrr LED. In order to
reset the amplifier, the power on-off switch must be switched off
for 2 seconds then turned back on. WARNINGI CHECK OUT THE
ANTENNA SYSTEM BEFORE OPERATING THE AIVIPLIFIER AGAIN.
If the heat sink temperature exceeds 175 degrees F. the
internal thermostat. will open, shuting down the power anplifier.
The rrTxrr LED will go out. The thermostat will automatically reset
when the heatsink cools down.
FUNCTIONS
The functions of the RFC 4-11O are controlled by the three front
panel switches.
POWER ......... This switch activates the power amplifier section,
as well as reseting the SWR protection circuit.
FM-SSB ........ In FM, the amplifier has a fast dropout when the
carrier is removed. In SSB, this dropout is

delayed, so the relays do not "chatter" while on
SSB. (see "DELAY AD-IUST" )
PREAMP This switch turns on the GaAs-Fet preamP. It can
be used even when the power amp section is off'
REAR PANEL CONNECTIONS
4 PIN "JONES".. Power is supplied thru this connector. This
allows quick removal of the amplifier, if needed'
FUSE A 35 Amp fuse provides protection in case of an
internal short circuit.
pHoNE JACK .... This jack is the external keying input. By
changing a jumper inside the amplifier, keying may
be a-complished by either a ground or a positive
voltage of +3 to +15 at I MA or less. See
.,EXTERNAL KEYING,..
NOTE: The unit is factory set for "plus voltage"
keying.
5 pIN DIN This jack is used for remote control of the
ampliiier. See the diagram "REMOTE CONTROL".
RADIO This coax connector is the input from the
transmitter or transceiver.
ANTENNA This is connected to the antenna.
INTERNAL CONNECTIONS AND AD.]USTMENTS
DELAY ADJUSTMENT . The "SSB delay" is varied by changing the
potentiometer, accessibte through the hole in
the cover on the left side of the unit.
EXTERNAL KEYING The amplifier is factory set for "plus keying"
keying. Most transmitters do not provide a
"ground" during transmit, but most do have a
positive voltage available at their back paneI.
You must consult your instruction manual, for
your particular radio, to locate this voltage.
This is then connected to the phono jack on the
ampJ-if ier.
To change the amplifier from "pIus" keying to
"ground" keying you must remove the cover and
move the wire connected to the phono jack from
the "+ To TXr'r pad to the " f To Tx" Pad. (see
sketch page 4)

/6
EXTERNAL KEYING - ..JUMPER,. POSITION
REMOTE CONTROL The 5 pin DIN connector allows remote control
of any of the functions of the ampJ-ifier.
Below is a diagram of a typical remote control
hook up. This can be built from commonly
available parts, to fit your own needs.
ra
L\
SSB FM
2
TO J2 J{. IOMFD
CABLE PLUG
(eacK)
4
REAR
PANEL
PO'v/ E R
PREAMP

WARRANTY
RF CONCEPTS warrants its products to be free from defects in
materill-ina woitcmansfiip for 5'years from date of purchase, wlth
ttre exception of the RF-power t?ansistors, whictr ate warranted for
6 months-.
- ----The unit must be returned to the factory, freiqht prepaid.
The warrantv card must have been submitted within the 15 days
after purchise. Anv unauthorized repair or chanqinq of the-
intern-al adiustment-s mav void this wArrantv.
RF CONCEPTS will piovide, free of chaiqe, both parts and
Iaborr ds necessary, tb correbt any defect 5cduring frithin the
warrantv peraocl.
This'warrantv applies to the oriqinal owner only.
This warrantl ab'pties only to th5se units tha! fail during
normal operation.' Ahir units that have been overdriven,
overvolthged, modified, accidentally damaged or misused will not
be covered.
USE OF THIS UNIT IN REPEATER SERVICE WILL VOID THE WARRANTY.
RF CONCEPTS will not assume any respgnsibi_lity foE damage to
any antenna, radio, or accessory co-nnect-ed to this-product. -
RF CONCEPTS
89I1-A MURRAY AVENUE GILROY, CA 95929
(4s8) e47-7373

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