Ameritron AL-82 User guide

AMERITRON AL-82

FULL POWER LINEAR AMPLIFIER

Rev. 3

The Ameritron AL-82 is a 1500 watt output linear amplifier that operates from 160 through 15 meters. The Ameritron AL-82X is the export model and covers 160 through 10 meters. The AL-82J is the export model for Japan and covers 160 through 10 meters. The AL82/X/J uses two 3-500Z tubes in a class AB2 grounded grid circuit. CW, FM and RTTY efficiency is improved by shifting the bias deeper into class B. The heavy duty power supply and RF components, combined with a forced air system utilizing chimneys, provide long service life for expensive components. The AL-82/X is shipped factory wired for 240 volt, 50/60 Hz power mains. The AL-82J is shipped factory wired for 200 volt, 50 Hz power mains.

LEASE READ THIS MANUAL BEFORE OPERATING THIS EQUIPMENT!

116 Willow Rd.

Starkville, MS 39759

U.S.A.

1. Carefully remove the amplifier, transformer, and tube from their shipping cartons.

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Inspect each item for visible damage. If any damage occurred during shipment,

the transportation company immediately.

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2. Save all packing materials in case you need to return your AL-82/X/J for factory service. The cartons have been designed to give maximum protection for this amplifier. Any units returned without proper packing may be damaged and shipping claims cannot be made. Contact the factory before re turning any units.

3. Remove the screws that hold the cover to the am plifier. Sl ide the cov er back an

remove it from the amplifier. Remove the package that is in the space where the transformer will be installed. This package contains two chimney s for the 3- 500Zs. Follow the Tube Installation steps on page 5 to properly install the chimneys. There is a small bag that contains the fuses, fuse caps and the remainder of the chassis screws wrapped in the packing material around the anode connectors.

4. Please read the GENERAL INFORMATION and SPECIFICATI ONS sections before attempting to install the trans former and tube. Go to the INSTALLATI ON section on

e 4 to begin installing the transformer and tube.

5. This amplifier must always be disconnected from the power mains before remo the cover. See the precaution on page 10. Please read the entire m anual to become familiar with the operation of the AL -82/X/J amplifier before attemp ting to operate th is e

ment.

NOTE: The AL-82J is the Japanese export version of the AL-82 amplifier. The AL82J utilizes a special power transformer for use with 200V AC, 50 Hz. The AL-82J will perform to specifications wh en the spe cial trans form er supplied is installed and it will cover 160 through 10 meters.

ing

FEATURES

1. Inexpensive tubes: the AL82 uses a pair of rugged 3500z tubes.

2. Fast warm-up time: the 3-500z requires only a few seconds of warm-u

time.

6. Two Illuminated Panel Meters: the AL-82 has two illuminated panel meters. The Grid Current meter provides a continuous read ing of grid current and i ndicates proper operation of the amplifier. The other meter reads Plate Voltage (HV), Plate Current (IP), Peak RF Watts ( P O ) and ALC.

3. SSB/CW switch: the bias voltage is switched to provide the best linearity on SSB or the lowest dissipation on CW operation.

4. ALC Indicator: the drive level is detected to provide a control voltage for the exciter. ALC prevents overdriving of the linear and reduces distortion from excessive drive

ower.

5. Vernler Plate and Load Adjustments: both tuning controls have vernler 6:1 reduction drives for smooth tunin

ECHNICAL SPECIFICATIONS AL-82

Input Circuit type: Pi-network, slug tuned coils maximum VSWR at reso nance: 1.2:1 minimu m 2:1 VSWR bandwidth:

20% maxi mu m d r i ve p o we r

permissible: 130 watts typical drive for full power out

ut: 100 watts

7. Operate/Standby Switch: filament and plate voltages are maintained while allowing the amplifier to be bypassed for "barefoot'' operation.

8. 12 Volt Auxiliary Jack: 12 volts at 100 mA is provide for accessories such as the ATR-15 Antenna tuner.

9. XMT Indicator LED: provides a front panel indication o proper amplifier ke ying by the exc iter dur ing opera tion.

Caution: This amplifier must be disconnected from the power mains before removing the cover . See the warning on page 10.

Metering: multimeter: plate current, plate voltage,

drive/ALC,

ALC: ne

Efficienc

ower output (PEP watts). Grid: grid current

ative going, 0-20V, adjustable, phono jack

CW: 65% typical

Output circuit type: Pi-L, Pi

/2 hour continuous c arr ier: 1 500 watts (B e low 1 8mHZ)

30 second continuo us carri er: 1800 watts p lus

/2 hour PEP two-tone test: 1800 watts

30 second PEP two-tone test :1800 watts

lus

Power Supply

circuit type: full wave bridge, capacitor input no load voltage: 3800V full load voltage: 3300V full load current: .8 amp regulation: 10% or better transformer: 32 lbs., hypersil capacitors: 26 mfd total, computer grade maximum draw at rated output: 13 amps at 240V AC -50/60 Hz

Tube type (2) 3-500Z continuous dissipation: 1000 watts warm-up time: approximately 30 seconds

Efficiency SSB (envelope crest): 62% typical MARSIWARC: yes,

andswitch set to nearest amateur band

Keying: requires re lay closur e or sinking to ground o f

ositive (+) 12 VDC at 100 mA, phono jack

RF Connectors: S0239

Line Connector: NEMA 6-15P 240V st

Dimensions: 18

Wei

ht: 77 lbs.

1/2" D x 17" W x 10"H

Frequency Covera ge: (AL-82 )-1.8 , 3.5, 7, 14, 18 and 21

MHz. User mod ified model s cover 24 and 28 MH z. ( AL82X/J)Export mod el s-1. 8, 3. 5, 7 , 14, 18 , 21 , 24 a nd 2 8 MHz.

Third Order IMD at Rat ed Output : -34 dB at 1500 w out put

ENERAL INFORMATION

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SAFETY IN TERLO CK

While the Amplifier's top cover is in place, the interlock switch closes to allow AC line voltage to reach the power transformer. When the top cover is removed, the interlock opens and disconnects the line voltage. This does not discharge the bank of power supply filter capacitors. Be sure to allow the filter capacitors to discharge before you touch anything inside the Amplifier. You can select the High Voltage function of the Multimeter to check the high voltage potential. Never attempt to defeat the safety interlock .

this amplifier with the unit plugged into the power line.

This Amplifier is designed to operate at full ratings when it is driven by an exciter that has approximately 100 watts of RF output. You can use an exciter that has lower output power, but the Amplifier's output will be less. If you use an exciter that delivers more than 100 watts, carefully adjust the driving power to avoid "over drive" and the creation of spurious signals, which create needless interference to other operators. We highly recommend that you use a monitor scope for continuous output monitoring. The display on an oscilloscope is the best way of determining the amplitude o f the voic e p e ak s which, if excessive, can cause "flat topping" and splatter.

IMPORTANT: In no case should you advance the power output control of your exciter beyond the point where the Amplifier's Power Output indication ceases to increase. If you turn the control past this point, nonlinear operation may occur.

WARNING - Neve r rem ove the co ver

FILAMENT SU PPLY

The filament circuit of this amplifier satisfies all requirements of the tube manufacturer related to tube performance and life. Inrush current is controlled by the transformer internal resistance and impedance, filament choke resistance and filament wiring resistance. To insure maximum life of the tube never replace any circuit components or wiring with substitute

The low voltage tap on the filament transformer primary provides the ability to operate the blower at slower speeds for reduce d no ise. Norm al amateu r o p e r a tion in CW and SSB wi ll not cause heat damage to components on any recommended tap. It is always advisable to use the maximum speed (air flow) that the level of noise permits to extend component life. Wiring information for the blower is shown in the "Transformer Connections" instructions on

e 6.

PLATE SUPPLY

The plate supply has a full wave bridge rectifier and a 1.8 KVA CCS rated tape wound hypersil transformer. Fi l tering is accomplished by a bank of high quality capacitors totaling 26 mfd (additional capacitance will not improve supply performance). The Plate Supply will not be harmed by normal continuous amateur operation at 1500 watt levels. Power is applied through RLY2 when the 12V DC low voltage supply is activated. A 10 ohm resistor limits the line current during the filter capacitor charge time to lower the stress on components. When the primary voltage approaches the full line value, RLY3 shorts the 10 ohm resistor and applies the full line voltage to the plate transformer. The 10 ohm resistor acts as a fuse during startup if the high voltage supply has a short.

A simple modification will allow operation on frequencies above 15 meters. Instructions for this modification are available by sending a written request for "Export Modification Instructions" along with a copy of a valid amateur license. There is no charge for this informati on. Export m o de ls are shipp e d w i th this modification and have an "X" or "J" following the serial number. Standard frequency coverages are indicated in the chart followin

the tuning instructions on page 10.

ECHNICAL ASSISTANCE

Technical assistance is available during our normal business hours on weekdays. The following information is required to assist you with operational problems:

1. Name and daytime phone number

2. Model and Serial Number

3. Date of purchase and dealer

Meter readings at all stages of the tuning proceedure are very important along with a complete description of the other e

ment used with our product.

Written assistance is also available. Due to time delays in processing mail, please allow at least three weeks for a written

AMERITRON

116 Willow Rd. Starkville,

Ms. 39759 Telephone

601)323-8211 FAX (601

The high voltage present on the plate choke and air variable

PERIODIC MAINTENANCE

capacitors attracts dust and dirt out of the air stream. It is particularly important that the high voltage areas at the bottom of the plate choke and the insulators on the air variable capacitors be dust free. These areas should be inspected every few months if the amplifier is operated in a dusty environment. Unplug the line cord, and wait about 90 seconds until the power supply capacitors discharge. Check the HV scale for zero voltage before removing the cover. Remove the cover and connect a jumper wire from ground to the anode connection of the tubes.

NOTE: Thi s is a safe ty wire tha t m u st b e in s talled wh en beginning service work. After service is complete, reverse the procedure to remove the safety wire. Remove the wire from the anode connection first and then from ground.

Use a soft bristle brush dipped in alcohol to clean areas mentione d pr eviously . In the event that c leaning is requir ed at frequent intervals, place a low restriction air filter material over the air inlet holes on the left front side of the cabinet near the filter capacitors. Most hardware stores stock suitable materials that ar e used as r eplacement filt ers for w indow ai r conditio n e rs.

The AL-82 has two illuminated meters. The Grid Current meter provides

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a continuous indication of the two 3-500z grid current. This exclusive feature of Ameritron amplifiers indica tes proper amplifier operation be tter than any other parameter. Do not exceed 300 mA on this meter during normal operation of this amplifier. The other meter reads Plate Voltage (HV), Plate Current (Ip), Peak RF Watts (PO) and ALC. These functions are selected with the Multimeter Switch.

Plate Voltage (HV): Read DC Plate Voltage on the 4000 v olt scale. This scale is 100 volts per division. Normal voltages are 3600 volts no load, 3300 volts full load.

Peak RF Watts (PO): Read Peak RF Wa tts on the 2000 watt scale. This scale has 50 watt divisions below 1000 watts and 100 watt divisions above 1000 watts.

NOTE: This circuit uses an emitter follower to charge a capacitor to the peak env elope voltage det ected by the ALC/P ower Board. Accur ate peak envelope power readings are given when the amplifier is connected to a 50 ohm nonreactive load. If the amplifier is used with a mismatched load, the power meter will read higher or lower than normal by a ratio up to the value of the SWR. Potentiometer R5 on the Meter Board (50-01140-

1) adjusts the calibration of the power meter.

Plate Current (Ip): Read Plate current on the 1000 mA scale. This scale is 25 mA per division. The maximum operating current rating of the 3-500z is 400 mA SSB or 900 mA CW.

INSTALLATION

TRANSFORMER INSTALLATION

Remove the cover of the amplifier. Remove the package that is in the plate transformer area. This package contains the chimneys for the AL-

82. There is a small bag that contains the fuses, fuse caps and the remainder of the chassis screws wrapped in the pack ing material ar ound the anode connector. Remove the top 7/16" nuts from the four transformer mounting bolts inside of the amplifier. Carefully remove the transformer from its shipping carton.

Place the transformer on the four the transformer is heavy. The side with the two high voltage secondary RED leads must be adjacent to the center panel(see Fig. 1). Now place a 7/16" nut on each bolt (see Fig. 2). Snug the nuts down manually. Do not tighten with a ratchet wrench.

/4-20 mounting bolts. Use care because

ALC: Indicates a relative drive level (average, not PEP) that can be estimated by dividing the Peak RF Watts scale by 10.

Remove the brass screws on the rectifier board (see Fig. 1). Install the RED lead ring terminals on the screws and replace the flat washers and Position the wires so that the black insulated areas are at least each other and any metal objects. Now tighten the

/4" hex nuts and the top flat washer from the two 6-32

/4" hex nuts.

/4" from

For 240V Operation (factory wired):

The four primary lea ds have c olored plas tic ins ulating boots over the quick disconnect terminals. Slide these back prior to installing the leads. Install the color coded boots as follows:(see Fig. 1)NOTE: Japanese export model (AL-82J) 82J) should follow the 240V operation steps to properly connect their transformer. The AL-82J is supplied with a special transformer for 200V operation.

1. BLUE (Brown wire) to the top relay terminal

2. YELLOW (Black/White) to the top terminal of terminal block

3. CLEAR (Black wire) to the second term inal of terminal block

4. RED

Brn/Wht) to the bottom terminal of terminal bloc

Now slide the colored insulating boots back over the terminals. NOTE: The green wire is not used for 240V operation. There is no green wire on the AL-82J export model transformer.

Important: The leads must be in the positions indicated by the color coded insulating boots (see Fig. 1) for 240V operation, or for 200V operation in Japan. For 220V operation, see page 5. Caution: Do not use the 220V wiring unless the line volt age is always b elow 220 VAC. The Standard USA vo l t a g e is 240 VAC, n o t 220.

TRANSFORMER INSTALLATION

steps below:

For 220V connections(see Fig. 3), follow the first three steps on the 240V operation on page 4, then follow the

1. Slide the RED boot back on the BRN/WHT

2. Clip the terminal connector off the wire and slide the RED boot off.

3. Remove the restraint from the GRN wire and slide the RED boot on to the wire.

4. Solder the terminal connector to the GRN wire.

5. Tape up the BRN/WHT wire because it will not be used.

TUBE INSTALLATON

Install the tubes, chimneys, anode. bracket and plate cap connectors as follows: (see Fig. 4)

1. After removing the packing material fro around the anode connectors, install the 3500z tubes. NOTE: One of the tube pins is offset. This offset pin "keys" the tube base and socket. Install the tube by aligning the tube pins with the socket contact terminals, then seat the tube with vertical pressure ONLY. Do not "rock" or "twist" the tube.

Fig.

2. Place the chimneys over the tubes and seat with the metal clips inside each chimney. Do not apply excessive force or the glass chimney may crack.

3. Attach the blocking capacitors to the anode

bracket and secure with the two 6/32 screws.

4. install the plate cap connectors on the tubes in

the positions shown. Be careful not to drop any hardware inside the chassis.

Fig. 4 Top View of 3-500z tubes

Caution: This page is only valid for transformers that contain these exact color codes for the primary winding. Early

production units did not contain a multiple tap transformer. If the terminal strip has all these color coded wires, then the unit has the multi

le tap transformer. FILAMENT/BLOWER WIRING INSTRUCTIONS The AL-82 and 82(X) amplifiers come prewired for 240V line voltage and with the blower prewired for medium high

fan speed. NOTE: The AL-82J Japanese export model is prewired for 208V line voltage and with the blower prewired for medium high fan speed.. This page gives filament transformer connection details for various line voltages and blower speeds. The five lug terminal strip and the single lug terminal strip are located immediately behind the ON/OFF rocker switch inside the unit. The drawing below shows the connection of transfo rm er leads and thei r purpose.

This chart shows the color code of the transformer leads and their purpose. The number in paren-

lug

thesis indicates the number of the terminal

that the transformer lead is connected to. The number three (3) lug is not used to change the filament or blower wiring. Do not add or remove any wires from the number three (3) lug. Refer to the drawing above. Use the lug numbers above when referrin

to both of the Filament connection chart and the Blower connection chart below.

FILAMENT TRANSFORMER LINE VOLTAGE There are two wires that connect to the terminal lugs which determine the Filament Line Voltage. The BL AC K w ire from the power switch and WHITE wire from rear of the unit connect to different terminal lug s depending on the voltage desired. The AL-82 and 82(X) come prewired for 240V operation`. AL-82J comes prewired for 200V operation". Refer to the chart below. Th e v oltag e listed in the chart below is the maximum line vo ltag e that should be applied to a given tap. Operation with line v oltag e in excess of the tap voltage selected can result in a reduc tion of tube life.

BLOWER CONNECTIONS

The GREEN and WHITE wires from the rear of the unit connect to the terminal lugs to control the air speed of the fan. The AL-82/X/J are prewired for the medium high speed setting'. Refer to the chart below. The blower connections can be moved to lower speed taps if air noise is excessive. Ameritron recommends using the highest speed tap that noise considerations permit. The lowest speed tap will develop sufficient air flow for standard amateur SSB and CW full power operation. The highest speed taps should be used for contest or RTTY operation.

* indicates factory shipped (AL-82/X) * * indicates factory shipped (AL-82)J

* indicates factory shipped

1. Connect the RF output of the exciter to the RF IN connector

on the rear of the AL-82 with 50 ohm coax. Use any good quality 50 ohm cable long enough to connect the amplifier to the exciter. The amplifier uses a standard SO-239 female that will mate to a PL-259 male connector on the cable.

2. Connect the existing station antenna system to the RF OUT connector on the rear of the AL-82 with RG-8 type coax. This connection uses PL-259 connectors.

3. Use shielded audio type cable with standard male phono plugs to connect to the RELAY jack on the AL-82. This jack has positive 12V DC open circuit and supplies

100mA of current when

4. Connect a short ground lead from a good earth and RF ground to the GND terminal.

5. The 12V connection on the rear panel provides 12V DC at 100

mA maximum to operate external dial lamps or accessories such as the ATR-15 Antenna Tuner.

6. DO NOT CONNECT THE "ALC OUT" SOCKET ON THE AMPLIFIER TO THE "ALC" SOCKET ON THE TRANSMITTER UNTIL INSTRUCTED TO DO SO IN THE TUNE UP PROCEDURE. This jack provides up to 20 Volts of negative voltage for transmitter gain control.

ulled to ground.

correct w

operation.

ge.

used fo

es.

INSTALLATION Cont.

LOCATION

Do not operate the Amplifier in excessively warm locations or near heating vents or radiators. Be sure air can circulate freely around a nd thr o ugh the Amp li fie r c ab i net . P rovi d e a n unobstructed air inlet for the blower. Do NOT place anything that will impede the free flow of air within 2 inches of the cabinet ventilation holes.

POWER CONNECTIONS

The AL-82 is supplied with a NEMA 6-15P plug for 240V AC operation. Operation with power main voltages below 200 volt is not 'recommended. A special transformer is required for 200\/, 50/60 Hz operation (see NOTE on page 1). Refer to the "Transfor mer I nsta lla tio n" se ct ion o n page s 4 and 5 fo r the

iring for 220 to 240 volt

VENTILATION

The AL-82 ventilation system has been designed and tested to maintain tube seal temperature safely below the tube manufacturer's rating at 1500 watts output with a 100% duty cycle when properly tuned. The blower in the AL-82 is a permanently lubricated type that requires no maintainence in normal operation. To insure proper ventilation in your installation

1. Do not block or unduly restrict the ventilation holes in the

2. The exhaust air flow is over 30 CFM. Do not "assist" the

3. Do not mount additional fans on the AL-82 cabinet.

4. The exhaust air

observe the following:

cover. Be sure that the amplifier the vent holes have o

air flow unless the fan exceeds the AL-82 blower CFM

a factor of 2:1.

levels. Do not place any heat sensitive objects in the exhaust air stream.

en air circulation.

will

ecome quite warm at higher power

is located in an area so

TUNING INSTRUCTIONS

Proper tuning of a gr ound e d gr id line ar amplifi er is b e st accomplished with an understanding of what each control does and v.hat the meters are telling the operator about the

NEVER REWIRE THE POWER SUPPLY TO BOOST THE HIGH VOLTAGE ABOVE 3700 VOLTS.

The wiring between the fuse box and the amplifier AC outlet must be No. 12 gauge or larger in order to supply the current required (13 amperes) without a significant drop in the line

lta

The outlet should be f

Connect a good RF and earth or water pipe ground to the ground post on the rear panel of the Amplifier. Use the heaviest and shortest connection possible.

Before you use a water pipe ground, inspect the connections around the water meter and make sure that no plastic or rubber hose connections are used. These connections interrupt electrical continuity to the water supply line. Install a jumper around any insulating water connections you may find. Use heavy copper wire and pipe clamps. It is best to ground all equipment to one point at the operating position and then

round this point as described abo ve.

ing operation. Excessive grid current, distortion on SSB or arcing in the tank components occurs when full drive power is applied to the amplifier without the "LOAD" set far enough clockwise (higher loading).

r 20 amper

The tunin

PLATE: This control tunes the amplifier output circuit to the operating freq ue nc y. It sho uld al ways b e a dj uste d for maximum output p ower or maximum gr id c urr e nt. Due to interaction with the "LOAD" control, a "touch-up'' should be performed after any load adjustments.

LOAD: This control adjusts the coupling of amplifier to the antenna or load. It should be adjusted to keep the grid current in the proper operating range. As the loading capacitance is reduced (by ro t at ing the c ont r ol to a hi gher fr o nt p a nel number), the coupling is increased. An increase in coupling will reduce grid current and increase the amount of drive the amplifier will accept without component damage.

A common mistake in tuning is to adjust the "LOAD" control at low drive

controls function as follows:

owers and apply more drive dur

It is important to remember the loading must be set properly for the PEAK power the amplifier is expected to develop. 50 watts PEP will be the maximum drive the amplifier will safely handle if the output of the amplifier is tuned with 50 watts of carrier drive. Any attempt to go beyond the amount of drive power the amplifier was originally tuned at will result in a rapid increase in grid current, splatter and even damage to components.

The "LOAD" control should be adjusted for maximum output power without exceeding the recommended grid current. DO NOT USE THE LOAD CONTROL TO REDUCE POWER IN A GROUNDED GRID AMPLIFIER. The drive from the exciter should be reduced if the amplifier plate current or output power is excessive. The "LOAD" setting should be increased if grid current is excessive. Any errors in adjusting this control should be made in favor of a higher load setting (clockwise).

OPERATION

CW PROCEDURE

Follow these instructions in numerical order. If the various meter readings are different than indicated, check the connectio n s from the excite r t o the amplifier and m ake sure they are

6. With exciter drive still at zero, place the MULTIMETER switch in the Ip position. Observe the 1000 mA scale. The meter should read zero (0). Place the STBYOPR switch in the OPR

osition.

Be sure the transformer is correctly installed and wired for your line voltage. See the "T ransformer installation" section on page 4 and 5 for wirin

1. Set the AL-82 front panel switches as follows: POWER TO OFF OPR-STBY TO STBY SSB-CW TO CW

2. Plug the AC line cord into the proper voltage outlet.

3. Set the Power Switch to the ON position. The meter l amps should light and the blower should start. Read the 4000 volt scale on the Multimeter. It should indicate 3600 volts nominal and no more than 3700 volts.

4. With the amplifier st ill on ST ANDB Y, tune t he exciter i nto a normal 50 ohm load according to the manufacturer's instructions. Turn the exciter drive fully down after tuning.

5. Place the amplifier mode switch in the CW position, the bandswitch on the same band as the exciter, the PLATE control in the dial range for the band selected and the load control as indicated:

details.

7. Key the exciter (no drive) and observe the plate current on the 1000 mA scale. It should be 75 mA. Place the CW-SSB switch in the SSB position. Plate current should now read 150 mA. Return the CW-SSB switch to the CW position.

Note: The no drive currents will vary up to 25% due to

onent and line voltage tolerences.

com

8. Apply only enough drive to indicate a grid current of 100 mA or an Ip of no more than 500mA. Tune the PLATE control for maximum output power or grid current. It is normal for the plate current to dip at this point. If the grid current goes over 150 mA, reduce the drive at once. Unkey the exciter.

9. Place the MULTIMETER switch in the PO position and

observe the 2000 Peak RF Watts scale. Increase the drive until 200 mA of grid current is indicated. Adjust the LOAD and PLATE controls for maximum output. The grid current ma

be lower now.

10. Advance the drive to 250 mA of grid current. Adjust the LOAD and PLATE controls for maximum output power. The out

11. Apply enough drive to indicate either 1500 watts of output power or 300 mA of grid current. Re-peak the LOAD and PLATE controls. The final grid current should be around 250 mA and the

ut should be over 1000 watts now.

late current below 900 mA.

ALC (Automatic Level Control)

ALC will

revent over-power operation.

The primary use of the ALC is to reduce the input drive power to a safe level for the AL-82. The maximum drive that the AL-82 will tolerate is approximately 130 watts. At this drive level the output of the AL-82 may be in excess of 2000 watts when properly tuned. The ALC should be connected and adjuste d after the am plifier is proper ly tuned on CW. Use a shielded audio-type cable with a standard male phono connector to connect the 0-20 volt negative ALC voltage to the exciter ALC input. Consult the exciter manual for proper connection details.

Setting the ALC ADJ Control

Proper adjustment of the rear panel ALC control can be achieved by the followin

1. Load the amplifier according to the tune-up instructions (with the ALC

2. Connect the ALC line a nd rotate the ALC control fully cl ockwise

3. Set the MULTIMETER switch to the PO position or observe an

4. Set the transmitter audio control about

5. Speak in the microphone in a normal tone of voice and observe the

steps:

disconnected from the exciter) to the desired max imum power.

lookin

at the rear of the unit.

external PEP meter or oscilloscope.

20oio

higher than normal.

reading on the 2000 RF Watts scale.

Adjust the ALC ADJ control on the rear panel until the amplifier

output is no more than the desired maximum power obtained in ste

SSB PROCEDURE

Tune the Exciter and Amplif ie r as de sc ribe d in "TUNE-UP CW PROCEDURE'".

1. Place the SSB-CW switch in the SSB position.

2. Adjust the exciter gain control to permit voice peaks to reac h the sa m e value the peak output meter read on CW when fully loaded. The plate and grid currents s hould re main well below 50% of the CW values during normal m odula tion.

SSTV, FM, RTTY, PACKET, AMTOR:

The plate current should be limited to 600 mA maximum. The grid current should be limited to 250 mA. Tune the amplifier for peak output power with the drive reduced to the grid and plate current below the ratings given.

NOTE:

Some t;xciters will put out short duration high power RF pulses when first keyed. Exciter power output peaks may reach or exceed full output level even if the exciter's power control has been adjusted to deliver reduced power under "keydown" conditions.

The amplifier loading control must be set high enough (clockwise) to prevent extre mely high energy leve ls from developin g in the plate and grid circuits of the amplifier. DO NOT "UNDERLOAD" THE AMPLIFIER TO REDUCE POWER. Never "retune" the amplifier to produce higher e fficiency with reduced drive. Poo r linearity, splat ter or even damage to components may result from failure to follow these instructions. Exclusive grid current usually indicates that the loading control is set too far counter-clockwise for the amount of drive being applied to the amplifier or that something in the antenna system has changed impedance (a rc ing) dur ing ope ra tion.

The exciter internal ALC will maintain linearity. The amplifier

WARNING!!

MAKE NO ATTEMPT TO PUT THIS AMPLIFIER IN SERVICE WITH THE COVER REMOVED! CONTACT WITH VOLTAGES INSIDE THIS AMPLIFIER CAN BE FATAL! ALWAYS DISCONNECT THE AMPLIFIER FROM THE POWER MAINS AND WAIT FOR THE FILTER CAPACITORS TO DISCHARGE BEFORE REMOVING THE COVER.

AL-82 SCHEMATIC Power supply shown wired for 240V operation

PARTS LIST

AMERITRON 116

)

Willow Road

Limited Warrant

Ameritron warra nts to th e ori ginal purc haser that thi s product sha ll be free from defects in mat er ial (e xc ept t u bes and RF o utp ut t ra nsis tors ) or wo rkma nsh ip fo r one year from t he da te o f or i ginal p urc has e.

During the warran ty peri od, A merit ron or an author ized Am eri tron ser vice fac ilit y will provide free of charge both parts (except tubes and RF output transistors) and labor necessar

To obtain such warr anty service, the original purchaser must:

(1) Complete and send in th e Warrant y Regis trati on Card . (2) Notify Ameritron or its nearest authorized service facility, as soon as possible after discovery of a possible defect, of:

(a) The mo del n umb er an d se ria l numb er , if a n y; (b) The iden tity of the sel ler and the appr oximat e date of purchas e;

(c) A detail ed d escr ip tio n of t he prob lem , i ncl udi ng de tails on t he eq ui pment (3) Deli ver the prod uct to the Ameri tron or the neares t autho rized service facility, or shi p the sa me in it s o rigi nal co nt ain er o r eq ui val ent, ful ly insur ed an d shipping charg es prepa id .

to correct d e fects in material or wo rkm ans hi

Correct main tenan ce, rep ai r and us e ar e i mpo r tant to ob ta i n p roper p er forma nce from this product. Therefore, carefully read the Instruction Manual. This warranty

Improper main tenanc e or r epai r, inc lu din g the i nst all at ion of pa rts o r ac cessories that do n ot co nfo r m to the q ual ity a nd spe cif ica tions o f t h e origin al parts. Misuse, abuse, neg lec t or improper installa ti on .

Accidental or in te nt ion al dam ag e.

All implied warranties, if any, terminate one (1) year from the date o the original purchase.

The foregoin g c ons tit utes Am er it ro n's ent ire obl iga ti on with res pec t to t his p roduct , and the original purchaser and any user or owner shall have no other remedy and no claim for i nci de nta l or co n seque nt ial d ama ges . Some states do n ot a llo w lim it a tions on how lo ng an im pli ed warr anty l as ts or do not al lo w th e e xcl usion o r limitation of inc ide nt al o r c on sequ en tia l dama ge, s o th e a b ove limita ti on an d exclusion may not app ly to you.

This warranty gives s pecif ic legal righ ts and you may also have ot her rig hts which

from state to s tat e.

var

PLEASE RECORD THIS INFORMATION:

Model Serial No: Date of Purchase Purchased From Warranty Card Mailed

Ameritron AL-82 User guide

Specifications and Main Features

Frequently Asked Questions

User Manual