Specifications

ManualsBrandsAMERITRON ManualsAmplifierAL-811H

PLEASE READ THIS MANUAL BEFORE ATTEMPTING TO OPERATE EQUIPMENT!!

UNPACKING INSTRUCTIONS

1. Carefully lift the amplifier by the bottom cabinet edge out of the shipping carton. Place the

amplifier on a firm, level surface and carefully inspect it for shipping damage. Contact the

shipper immediately if any damage exists. Save the carton and packing material for possible

shipping in the future.

2. Remove the twelve screws holding the cover on with a number 2 phillips screwdriver.

Carefully lift the cover off the amplifier. Save the screws to rescuer the cover. Note that the

AL811H is shipped with the fuses and fuse caps inside the amplifier.

3. Locate the fuse pack with the two 12 ampere fuses and fuse caps. If additional screws are

needed, they will be in the fuse pack also. NOTE: Fuses supplied are for 120/110/100V

operation (Models AL-811H/HY). If you are rewiring the AL-811H for 240/230/220V

operation, you must use 8 ampere fuses. The AL-811HX export model is pre-wired for

240V operation and is supplied with 8 ampere fuses.

4. Remove the foam packing material (around the tubes) that secures the 811A tubes during

transit. Carefully unwrap the tubes. Do not dislodge or break the shaft that is connected to

the rear input bandswitch wafer.

5. To install the tubes in the sockets, be sure the large diameter pins line up with the two large

diameter holes in each socket. Do NOT rock or twist the tubes excessively during the

installation. If the tubes are already installed, check them for proper seating. If necessary,

press the tubes down into their sockets with gentle force. Do not rock or twist the tubes

excessively. Also, check that the anode caps are secure and that they did not come loose

during the unwrapping process.

6. The white ceramic anode connector will have to be removed from the top metal cap of each

tube if it ever becomes necessary to remove the tubes from the amplifier. This can be a

difficult procedure because the high clamping force of the internal springs in the anode

connector may hold it to the cap very tightly. The tube will break if direct upward or rocking

pressure is applied in an attempt to remove the connector. The safest way to remove the

ceramic connector is to lift the tube out of its socket. A twisting or spinning pulling motion

can then be applied while holding the ceramic connector firmly until the tube and connector

are separated. Repeat the procedure with each tube.

7. Install the cover with the vent holes to the left (near the tubes) by installing the back screws

first. Install all the screws loosely and tighten them only after all the screws are in place.

8. Install the fuses and fuse caps on the back of the unit. Read the manual to become familiar

with the operation of the AL-811H amplifier.

Summary of content (11 pages)

PAGE 1
PLEASE READ THIS MANUAL BEFORE ATTEMPTING TO OPERATE EQUIPMENT!! UNPACKING INSTRUCTIONS 1. Carefully lift the amplifier by the bottom cabinet edge out of the shipping carton. Place the amplifier on a firm, level surface and carefully inspect it for shipping damage. Contact the shipper immediately if any damage exists. Save the carton and packing material for possible shipping in the future. 2. Remove the twelve screws holding the cover on with a number 2 phillips screwdriver.
PAGE 2
AL-811H LINEAR AMPLIFIER FEATURES The AL-811H is a grounded grid linear amplifier developed by Ameritron using low cost 811A power triodes. It operates in class AB2 for SSB and CW. 1. Fast Warm Up Time: The 811A tubes take approximately 10 seconds to warm-up. 2. Long Tube Life: The 811A tubes are long life, reliable transmitting tubes. 811A tubes offer rugged, reliable operation even on RTTY and SSTV. 3. Tuned Input: A Pi-Network tuned input matches the 811A tubes to 50 ohm exciters. 4.
PAGE 3
GENERAL INFORMATION SAFETY INTERLOCK The interlock switch stays closed to allow AC line voltage to reach the power transformer as long as the AL-811H's top cover is in place. When the top cover is removed, the interlock opens and disconnects the input 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.
PAGE 4
METERING FUNCTIONS The AL-811H has two illuminated panel meters. The right meter reads PA grid current up to 200mA. The normal current with a single tone (carrier) signal will be 150mA to 175mA. If the current is too high during full power operation, the loading control should be advanced to a higher setting. If the current is too low, the loading control should be turned to a lower setting. The left meter reads PA high voltage up to 2000 volts and plate current up to 750mA.
PAGE 5
INTERCONNECTIONS 1. Connect the RF output of the transmitter or transceiver to the RF IN connector on the rear of the AL-811H with 50 ohm coax. Use any 50 ohm cable (RG-58 is fine) with PL259 plugs. 2. Connect the existing station antenna system to the RF OUT connector on the AL-811H with any 50 ohm coaxial cable capable of carrying 650 watts. 3.
PAGE 6
TUNE-UP CW PROCEDURE Follow the instructions in numerical order. If the various meter readings are different than those indicated in the instructions, check the connections from the exciter to the amplifier and make sure they are correct. Consult the manual for the exciter, if necessary. Be sure the transformer is correctly wired for your line voltage. See the POWER CONNECTIONS instructions on page 4 for wiring details. 1.
PAGE 7
OPERATION OF OTHER MODES SSB: Tune up the exciter and amplifier as described in TUNE UP section and switch the exciter to SSB. Normal ranges of meter readings on SSB are between 20 and 50 percent of the CW carrier readings. This is due to the different peak-to-average power ratios in the operator's speech waveform. The only true way to measure peak output power is with a good peak reading wattmeter or monitor scope. A whistle should produce the same values obtained on CW.
PAGE 8
PERIODIC MAINTENANCE The high voltage present on the plate choke and air variable capacitors attract dust and dirt out of the air stream. It is particularly important that the high voltage areas at the bottom of the of the plate choke and the insulator 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. connect a jumper wire from ground to the anode connection of the tubes.
PAGE 9
Power supply shown wired for 120V operation * 9
PAGE 10
AL-811H INPUT CHART BAND C3 (pF) L1 C4 (pF) 160 80 40 100 (208-5174) 750 (208-5668) 28.75T (405-1287) 23.75T (405-1237) 13.75T (405-1137) 20/30 15/17 10/12 330 (208-5331) 120 (208-5606) 180 (208-5605) 9.75T (405-1097) 6.75T (405-1067) 4.
PAGE 11
F2 11 8 Amp (240 Vac Operation) 755-1432