Amp Supply LK-500ZB series User manual

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INTNCITXrcTION
The Amp Supply LK500ZB Linear Amplifier is a compact 2500
Watts PEP 160-15 meter amplifier of modern design. It is a high
performance pieee of equipment requiring a minimum of maintenanee
through years of operat ion. The LK500ZB was engineered
conservatively, with Ameriean components and ingenuity. The
unit is field-tested and rated for 2500 Watts PEP input
continuous in SSB service and 2000 Watts DC input along with many
MARS operating frequencies, without modifications.
T\ro EIMAC 3-5002 tr iodes are employed, operating in grounded
grid in conjunction with a solid state power suppty eapable of
either 11?V or 234V operation. The LKS00ZB uses a double duty
cool ing system which al lows cool ing of not only the tubes, but
the power supply as wel l.
Tuning the LKs00ZB is a simple procedure, since the unit is
designed for long-term stabil ity in virtual ly any operating
situation. Tuned input and standard relay switehing circuitry
makes the LKS00ZB compatible with any solid state or tube
transeeiver or transmitter available. The LKs00ZB, despite its
straight-forward des ign and minimal user required adjustment, is
nonetheless a sophistieated electronic instrument. Therefore, if
the unit is operated outside the parameters outl ined in this
ownerts manual, it is possible that damage ean resul t.
Please read this mqnual careful ly before putt ing your
LK500ZB on the air.
XANNING
TO TAKE FULL ADVANTAGE OF THE LK500ZB COOLING SYSTEM, IT IS
REQUIRED THAT THE AMPLIFIER BE OPERATED WITH AT LEAST Z-LI2N
CLEARANCE ON BOTH SIDES AND TOP OF THE UNIT.
CAUTIONS
1. Make no attempt to put the LK500ZB in service outside of the
cabinet. Contact witn high voltages in this Amplifier can
be FATAL TO THE HUMA}.I BODY.
Never attempt to operate the LKs00ZB with drive power of
more than 125 Watts!
Never attempt to operate the LK500ZB without first
eonnecting it to an antenna with an SWR of less than 2zl, or
a 50 Ohm dunnny load of suffieient power handling eapaeity or
ser ious damage may resul t to the ampl i f ier.
2.
3.

4. Do not, under any eireumstanees, operate the LK500ZB from a
LL? Vol t I ight ing cireui t beeause the eireui t conduetors are
not large enough to safely earry this load.
5. Never run Amplifier from an extension cord.
6. Do not attempt to change jumper eonnections on primary of
Amplifier without first removing power frqm the LK500ZB.
'l . Do not eover the top of the LKs00ZB wi th books, papers or
other pieces of equipment or overheat ing may resul t.'
Do not use different tuning proeedures other than indicated
in this manual.
When eleaning the LK500ZB never blow high pressure air
direetly into the fan blades. Spinning the fan at higher
speeds than it was designed for can eause damage and freeze
the rotor assembly of the fan. Use a brush in cleaning the
fan assembly.
SPECIPICATIONS
FREQUENCY COVERAGE: Ham bands 160 through 15 meters*. Non-
amateur frequencies between 1.8-4.0 and
6.5-24mHz may be eovered with adjustment of
the tuned input.
8.
9.
TYP ICAL OUTPUT:
DRIVE REQUIREMENTS
FOR TYPICAL OUTPUT:
INPUT IMPEDA}iICE:
OUTPUT IMPEDANCE:
INTERMODULATION
DISTORTION PRODUCTS:
HARMONIC SI]PRESSION:
POIVER REQUIREMENTS:
DIMENS IONS:
WE IGTIT:
f00 Watts PEP SSB,
RTTY, SSTV
50 Ohms - tuned input
?5 Watts CW, 60 Watts
on eaeh band
1500Watts on SSB; 1200 Watts CW and 900
Watts on SSTV, RTTY
Adjustable Pi-network matches 50 Ohm I oad
with SWR not to exceed ZzL
In excess of -33d8 below PEP
In exeess of -45d8
11? Volts 50/60 Hertz 25 Amps or 234 Volts
50/60 Hertz L2.3 Amps
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TOPTIONS: Ten Meter Modifieation Kit for I ieensed
US amateurs
XPort Model, factory built-in 10 meter band
are subjeet to change without notice or
Speeifications
obI igation. FRONT PANBL CONTROLS
ON-AC ROCKER SWIrcH - Turns power on and of f .
)OIIT-STBY ROCKER SWITCI1 - Turns the amp from standby to operate
mode.
BAI.ID-SWITCH - Selects desired bands.
PLATE AND LOAD KNOBS - Tuning adjusts Pi-Network eapacitors in
tank eircuit for proper resonance and Ioading on al I bands.
PLATE CITRRENT METER - Cont inuous I y mon i tors pl ate current of 3-
500?, tubes.
GRID-VOLT METER - By use of the
volts (0-3500 V or grid current
RBAR
RF-IN - For eonneeting to exciter RF output.
RF-OUT - For conneeting the LKS00ZB to an antenna.
RLY - For eonneeting to exciter auxilary jack to activate T/R
Relay in the LK-50028.
I(EY IN - QSK ONlY-station key, must be a bug, hand key or a keyer
with a reed relay.
KEY OUT QSK ONLY hooks to the key in jack on a QSK
ttansce i ver .
QSK VOX SWITCH - place in the QSK position when operating QSK CW.
INSTAL
Make no attempt to put the
the eabinet contaet with
FATAL! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !
meter switeh ean monitor plate
0-350 mA.
JACKS
LAT I ON
Amplifier in serviee outside
voltage in this Ampl if ier CA}I
3
of
BE
1.

2.
3.
Unpgekigg - Careful ly remove your LKs00ZB f rom its packing
earton, and examine it closely for signs of shipping
damages. Should any damage be apparent, notify the del ivery
carrier immediately, stating the full extent of the damage.
Ins.tell 3.-ä002lub.ss.. WARN I NG The LKS00zB has been
shipped from the faetory without the tubes. These are
packed separately. Be sure to instal I these items before
turning on the LKs00ZB.
Iuhe lnrtgllgtia.n. 'Caref u I I y remove the EIMAC tubes f rom
their boxes. Careful ly move the two parasitic chokes in the
tank compartment of the LKs00ZB out of the way and instal I
tubes. When tightening down the plate caps, only tighten
screws snug--overt ightening may damage tubes. Remove
packing from under the tuned input board.
Fil I out the enelosed warranty registration card and return
to Amp Supply.
La.ggtio.n. In general, the loeation of the LK500ZB is not
eritieal, however, there are certain considerations which
must be given to insure optimum performanee. Extremely hot
locations, sueh as near radiators or heating units should be
avoided. Do not cover the top of the Ampl ifier case with
books, papers, or other pieces of equipmentr or overheating
may oeeur. The sides of the Amplifier ease must not be
obstrueted and should not be placed closer than 2-Ll 2 inches
fromawall or the air inlet and outlet for the blower will
be blocked and overheating of the Amplifier tubes may occur.
6. Bqwer-BeguiggmenLg. The LK500ZB has a built-in eontinuous-
duty power supply which ean be operated from either 234 V AC
or 1l? V AC 50/60 Hz. A jumper network is provided inside
of the Ampl ifier.
The LK500ZB is shipped from the factory with jumpers
eonnected to operate on 234 V AC. It is highly tecommended tha
the LKs00ZA be operated from its own 234 15 A (or greater)
cireuit. If a 11? V cireuit is all that is available, it should
be fused for 30 A and circuit conduetors should not be less than
#10 and no other equipment should be operated from this cireuit.
Never run Arnpl if ier f rom an extension eord.
On the next page are pietor iaI s of jumper eonneet ions
located in the left rear corner of the chassis for both 234 V and
1l? V operation. The jumpers must be connected as shown or
severe damage to the LKs00ZB components may result. Remove
exist ing jumper before instal I ing the new ones.
4.
5.

JUM PERS
234V
WARNING
@MPLETELY REMOVE POWER FROM LKSOOZA BEFORE ATTEMPTING
JI]MPER @NNECTIONS ON BACK OF AI\4PLIFIER.
7. Anqplif.ier Inet-gllg.tiqu. Af ter the tubes have been
connect your LK500ZB to your power source.
Amplifier Controls as follows:
TO CHANGE
instal led,
Set the
AClON
)O,IIT/STBY
METER
- OFF
- STBY
- VOLTS
Turn the unit on. Plate voltage wil I read between 3000-3300
VoIts DC. Turn the unit off.
8. Qg.hle--Ins.lelLgtie.n. (see Diagram c) Us ing 6t I ength,
connect a 52-Ohm coaxial eable between your exeiterrs RF Output
and the LK500ZB rear panel RF Input conneetor. Next eonneet
another short I ength of 52-Ohm coaxial eabl e (nC-gU or
equivalent) from the RF Output connector to a suitable Wattmeter
and Antenna system. Nextr a piece of shielded cable should be
installed between the RCA type jaek on the rear panel marked RLY
and the accessory contaets of your exeiter. These should be
normal ly open contacts that are elosed on TRANSMIT. (See your
exciter operatorts manual.) This eompletes hookup of the
LKS()()
DIAGRAM C
EXCITER LK-500
Antenne. B.eguiremg&tg. The LKs00ZB has been designed for use with
antennas resonant at the operat ion frequeney and hav ing
approximate impedances within the limits of 30 to ?5 Ohms.
TO 50rl
ANTENNAi
FILTER

The nominal output impedance of the LK500ZB is 50 Ohms and the
SWR of this load should never exceed 2zl. Although there are
many types of antennas whieh wil I meet these requirements, the
simplest is a one-halt (ll2) wave dipole eenter fed with 52 Ohm
coax. For a detailed diseussion on antennasr w€ suggest
referring to an appropriate antenna book.
Most practical antennas exhibit an SWR range over a complete
amateur band that exeeeds 2zL. For this teason we reeommend
using an antenna matching network whieh will allow the LKS00ZB to
work into a 50 Ohm resistive load for maximum power transfer into
the antenna. The new AT-3000 by Amp Supply Co. is a perfect
companion tuner for the "LK-500 series of ampl ifiers.
CAUT I ON
NEVER ATTEMPT TO OPERATE THE LKs()()ZB WITHOUT FIRST CONNECTING IT
TO AN ANTENNA OR 5() OHM DUMMY LOAD OF SUFFICIENT POWER HANDLING
CAPACITY OR SERIOUS DAMAGE MAY RESULT.
Gra.und--Seguirsmsnts. The LKs00ZB should be attached to a good
earth ground through as short and as large a ground strap as
poss ibI e for best resul ts. A ground post is prov ided on the rear
of the LKs00ZB ehassis for this purpose. It is always a good
idea to eonneet the chassis of al I assoeiated equipment together
and ground them at one point to avoid ground loops. We recornrnend
that all of the equipment in your station be eonneeted together
and grounded at the Antenna Tuner.
TUNING PROCBDUBB
WAR}IING
THIS TINIT IS SHIPPED BEADY FOR 294 VAC OPERATION. IF YOI,'R
APPLICATION REQUIRES RUNNING THE LK500ZB ON LL? VAC, SEE nPOI{ER
REQUIREMENTSN T]NDER INSTALIÄTION INSTRUCTIONS.
l. Set the Bandswiteh to the desired band.
2. Set the Load Control on number shown on tuning chart.
3. Set the Tune Control on numbet shown on tuning chatt.
4. Set the On/Ac Control to ON.
5' Set the xmit/Stuy Control to J(MIT.
6. Set Meter switch to grid current. (tnis is read on Plete/Grid
Current Meter ) .

7.
8.
9.
Insert a small amount of exciter drive until the plate
eurrent begins to rise to approximately 400mA.
Rotate the Tune Control for maximum output on your station
wattmeter.
Go between Tune and Load for maximum output.
1 KW input (Plate Voltage x Plate Current = Power Input)
Example: PIate Current = 40OmA
Plate Voltage = 2500 V DC
.4 x 2500 S = 1000 Watts Input
10. Inerease drive power. Repeat steps 8 through 10 until you
obtain desired output.
11. During tune up alternately monitor Grid and Plate Current.
12. Grid current can be reduced by sl ightty decreasing the Load
control. Turn control to right, elockwise.
13. ALWAYS TT]NE FOR MN(IMUM OUTPUT !
14. TI]NE FOR MAXIMI,]M OUTPUT ATALL TIMES !!!!!!!!!!!!!!!!!!!!!!!
TARNING
CT]RRENT LIMITATIONS FOR NORI\4AL OPERATIONs
Plate Current. .
Grid Current .. r. not to exeeed 950 MA. in full tune-up
under tune up, RTTY, or SSTV, never to exeeed
350 mA.
on SSB voiee peaks shoul d average I ess than
25()mA whi le operat ing.
.on Cw between 100 and 25OmA, depending on
aa a
ao sending speed.
. SENYICB DATA
ct\ItTIe{
EXTREME CARE MUST BE TAI{EN I{ITENEVER MAI{ING AI\TY ADJUSTMENTS INSIDE
THE LKS()()ZB.
Remqying--Igg-QqygL. After eompl etely diseonnect ing the LK500zB
from power wait 30 minutes so aIl electrolytic eapacitors have
diseharged through their bleeding resistors. The top eover ean
then be safely removed by taking out the top and side row of
serews.

Cle.euing_Amplitier_Cgmpallmenl-. Since the Ampl i f ier compartment
is forced-air cooled, it will collect particles of dust which
must be removed periodically. The frequeney of eleaning will be
governed by how many hours the LK500ZB is operated, and by how
clean its environment is. When the blower blade aecumulates a
large amount of dust, the Ampl ifier should be cleaned. The best
way to elean the LK500ZB is to remove the top eover and blow the
dust out with eompressed air. If eompressed air is not
available, a soft-bristled one-inch paint brush can be used to
brush the Arnpl if ier clean. trARNING
DO NOT BLOW AIR DIRECTLY INTO THE FAN BLADES. USE A BRUSH IN
CLEA}.IING THE BLADES OF .THE FA}iI.
IUbe_Sgplggemgnl. If it becomes necessary to replace the tubes
in the LK500ZB the same brand should be used. A new tube kit 'is
available from Amp Supply Co.
IfA.Uble__thA.O.ling. Careful eonsideration has been given to the
design of the Lk500ZB to keep maintenance problems to a minimum.
However, it is possible that some problem will arise which eannot
be eured by tube substitution. If this occurs, we suggest that
you eontact our customer service department, describing your
problem in detail. Inelude full information coneerning external
connections, control settings, assoeiated equipment, antenna,
being sure to indieate the serial number of the LKs00ZB. Do not
return equipment to the faetory without prior authorization.
Belurning --the --t Kt00ZB--tq -ihe -laelsLy -f.a.L -ssryiss. ob t a i n a
return authorization from the customer service department. Amp
Supply Co. will assume no responsibility if the transpottation
eompany refuses to pay a damage claim due to improper packing or
I aek of insurance. Be eertain to remove the tubes pr ior to
shipping and return the tubes in a separate earton.
OPEI I,ETTEN, TO I,K-sOO SERIES ATTPLIFIER (IWERS
I would like to take this opportunity to thank you for the
purchase of your new LK-s00-ZB from Amp Supply Co. The entire
workforce at Amp Supply, shares in my desire for your complete
satisfaction and enjoyment of the LK-s00. We have done our best
to insure that every amplifier produced is of the highest
qual i ty.
I sol icit any and al I eomments about your new LK-500-ZB. Amp
SuppIy Co. is here to serve trYOUtr. You are the most important
person in our business as a satisif ied eustomer and we are
dependent on you. I wish for you to be a part of out business.
Your satisifaetion is the I ife-blood of Amp Supply. Stated
simply, eustomets return to and buy repeatedly from eompanies who
satisfy and please them.
God Bless You and ?3, Denny KSKX(

NEbI OPTIONS
HI/LOl,, AIR SPEED
Your new amplifier is equippEd with a high-low cooling system.
The switch on the front of the amplifier labe'led "H" and "L" is
for this system. 0perate the amp in "H" position for tune-up,
and RTTY and SSTV. Operate the amp in the "L" position of Ct'l
and SSB operation. i
ALO
A new circuit, AUT0MATIC L0CK OUT (ALO) is available on the 500
and 800 series amp'lifiers.as an option. This circuit prevents
excessive p'late current when the amplifier is operating by putting
the amp in standby mode. l,lhen the ALO circuit is activated the
ALO'light on the front pane'l will be lit and the plate current
nreter wiII read zero. The circuit is automatically. reset after a
one second delay. If excessive plate current still persist the
circuit will oscillate on and off at one second intervals until
the plate current is below the factory preset limits. 0n the
LK-500 the limit is set at I amp and the LK-800 limit is set
at 1.5 amps.
5