• AL-800H Instruction Manual WARNING!! NEVER APPLY POWER TO THIS AMPLIFIER WITH THE COVER REMOVED! CONTACT WITH THE VOLTAGES INSIDE THIS AMPLIFIER CAN BE FATAL! PLEASE READ THIS MANUAL BEFORE ATTEMPING TO OPERATE EQUIPMENT! Improper or abusive operation of this amplifier can damage the tubes or other components in this amplifier. • Remove the 3CX800A7 tubes from their shipping cartons. Carefully unwrap the tubes and inspect them for visible damage.

Eu Bebo Sim Velhas Download. Look for dented anode coolers and broken or bent pins. Roll the tubes over slowly and listen for loose internal materials.

Ameritron 10 Meter Mods Pdf. Before you can read articles, read and write messages in the forum or download manuals from mods.dk you must first create an account and be a registered member. Modifications and service of AL811 amplifier Ameritron. AL811H, highest peak.

Contact either your Ameritron dealer or Ameritron immediately if any damage exists. • AL-800H Instruction Manual Table of Contents Unpacking Instructions...iv Features....1 AL-800H Technical Specifications..2 General Information...3 Safety Interlock...3 ALC...4 Dynamic Bias...4 Timer - Overload Circuits...5 Grid Overload Protection...5 Thermal Overload...5 Cathode Warm-up Timer...5 Power Supply...6 Heater Supply...6 Plate (HV) Supply...6 Meters...6. • Power Supply / SWR Board (50-0800H-1)..25 Tuned Input Board (50-0800H-2)..26 AL-800H Tuned Input Chart..26 Meter Board (50-0800H-3)...26 Timer / Overload Board (50-01172)..27 AL-800H Main Chassis Parts List..28 Frequency Coverage...29 Amplifier Tuning Log...29 Notes...30 Schematics...31 Wiring Diagram...31 PWR Supply / SWR Board...32. • A multi-voltage heavy-duty transformer with a unique 'buck-boost' winding allows adjustment of the primary voltage to 14 different voltages centered on 115 and 230 volts.

This versatile Ameritron feature allows the user to select the optimum primary voltage for maximum performance and life. • AL-800H Instruction Manual AL-800H Technical Specifications * Input: Circuit type: Pi-network, slug tuned coils Maximum VSWR at resonance: 1.3:1 or less Minimum 2:1 VSWR bandwidth: 20% of center frequency Maximum drive power permissible: 100 watts PEP Typical drive for full power output. • Ameritron Al-800H 1500 Watt Linear Amplifier Instruction Manual The Ameritron AL-800H is a 1500 watt output linear amplifier that operates from 160 through 15 meters. The AL-800HX is the export model that operate from 160 through 10 meters.

Export modification instructions are only available with proof of a valid amateur radio license. • The AL-800H contains an exclusive bias circuit that reduces the idling (quiescent) current very close to the tube's cut off region.

The power amplifier tube in the AL-800H has a full resting period of very low dissipation between dots and dashes on CW and between words on SSB. The lower idling current dramatically reduces component temperatures on both CW and SSB. • AL-800H Instruction Manual Timer - Overload Circuits CAUTION: Never modify or disable protection circuits without factory approval. Doing so with void all manufacturer's warranties. Grid Overload Protection This amplifier contains a fast acting electronic grid protection circuit to enhance tube life. The amplifier will quit operating and the 'OL'. • AL-800H Instruction Manual Power Supply Heater Supply The heater circuit of this amplifier satisfies all requirements of the tube manufacturer related to tube performance and life.

The heater voltage and inrush current are controlled by the power transformer's internal resistance and impedance, heater choke resistance, heater wiring resistance, and the step-start circuit. Wattmeter Circuit The AL-800H wattmeter circuit uses an accurate directional coupler followed by a true peak detector circuit. This circuit will accurately determine the true peak envelope power (PEP) of normal voice waveforms. If the load SWR is high, the true power reading can be obtained by subtracting the reflected. • This circuit rapidly disables the amplifier when excessive grid dissipation occurs. In the AL-800H a grid current of 150 mA (at 100 watts of drive) produces the maximum rated grid dissipation of 4 watts per tube.

This amount of grid current will also safely disable the amplifier within a few milliseconds. • The use of low quality tubes, tube that have been stored for extended periods, or abused tube will increase the likelihood of a 'gas arc'. Ameritron recommends using only current code date Eimac 3CX800A7 tubes. • Replacement packing materials may be purchased from Ameritron if original packing materials are unavailable or damaged.

CAUTION: Never ship this amplifier with the tube installed. Ameritron will not be responsible for shipping damage caused by improper packing.

• Power Connections The AL-800H is supplied with a NEMA 6-15P plug for 240 Vac operation. Full duty cycle operation with ac supply voltages below 200 volts is not recommended. The TRANSFORMER CONNECTIONS section on page 13 show the correct wiring for various supply voltages.

• AL-800H Instruction Manual Grounding Connect a good RF and dc ground to the ground post on the rear panel of the amplifier. Use the heaviest and shortest connection possible.

The best materials to use for ground connections are (in order of effectiveness) smooth wide copper flashing, copper tubing, or solid copper wire. • JUMPER CONNECTIONS chart for maximum protection. Interconnections Connect the exciter's RF output to the 'RF IN' connector on the rear of the AL-800H with 50 ohm coax. Use any good quality 50 ohm cable long enough to connect the amplifier to the exciter. This amplifier connection uses a standard SO-239 female that mates with a PL-259 male connector on the cable. • Shielded audio type cable with a standard male phono plug should be used to connect to the 'RLY' jack on the AL-800H.

This jack has positive 12 Vdc open circuit and supplies 100 mA of current when pulled to ground. The relay circuit has an internal back pulse canceling diode to protect sensitive exciter circuits from damage. • ALC Metering, Controls, and Adjustments ALC Metering Functions The 'MULTIMETER' switch in the AL-800H has two positions that indicate the functioning of the ALC circuit. These positions are as follows: ALC.In this position the multimeter measures the output voltage of the ALC detector. The full scale reading of the ALC detector voltage is 35 volts.

• AL-800H Instruction Manual ALC Controls The position of the 'ALC SET' control determines the grid current value that will begin to produce ALC voltage. Rotating the 'ALC SET' control counter-clockwise reduces the maximum grid current obtainable and the available RF power output. Rotating the 'ALC SET' control clockwise increases the maximum grid current level. • AL-800H Instruction Manual Rear-Panel 'ALC LIMIT' Control The 'ALC Limit' control (rear panel) limits the maximum voltage available from the ALC circuit. This control is necessary only because the ALC response times and voltage requirements for exciters have never been standardized. The ALC voltage requirements may even vary between different models produced by the same manufacturer.

• A second method of determining linear operation is to monitor the peak RF output power carefully on the AL-800H's internal meter. Determine the maximum obtainable RF output power and reduce the exciters power until there is a noticeable margin from the maximum output power.

This will insure some reserve power is available for random voice peaks. • (clockwise) to prevent excessive voltage and arcing in the tank circuit or excessive grid current. Repeated tripping of the grid overload circuit probably indicates the 'LOAD' control is set too low. Set the AL-800H front panel switches as follows: POWER OPR-STBY. • AL-800H Instruction Manual Place the amplifier's 'BAND' switch on the same band as the exciter. Set the 'PLATE' control and the 'LOAD' control as indicated below: Frequency Plate Load 1.810 3-1/2 6-1/4 3.600 1-3/4 0-1/2 7.050 1-3/4 10.125 5-1/2 2-1/2 14.050. • AL-800H Instruction Manual >STEPS 10a AND 11a REQUIRE A CONNECTION FROM THE AMPLIFIER'S ALC OUTPUT TO THE EXCITER'S ALC INPUT.

>STEPS 10b AND 11b SHOULD BE USED IF THE EXCITER AND AMPLIFIER ALC LINES ARE NOT CONNECTED. NOTE: Step number 10 requires the simultaneous observation of the plate current (Ip) and the grid current (Ig). • AL-800H Instruction Manual 'ALC SET' Control Proper adjustment of the front panel 'ALC SET' control accomplishes the following: The exciter's power is limited to a value that will produce a fixed amount of grid current in the amplifier.

The front panel 'ALC SET' control determines the maximum grid current that can be produced. • QSK-5 unit. The QSK-5 operates directly from 120 Vac power lines. Ameritron also offers an internal QSK board as a space-saver for the AL-800H. This internal board is slightly less expensive.

However, it provides less flexibility and serviceability than the external QSK-5 unit. • ALWAYS be cautious of heat. Many components inside the amplifier operate at high temperatures. NEVER make any unauthorized component or circuit modifications to this product. The only acceptable source for modifications is Ameritron or a source approved by Ameritron.

Unauthorized modifications almost certainly will increase the risk of equipment failure or personal injury. • AL-800H Instruction Manual Parts List Power Supply / SWR Board (50-0800H-1) Designator Description Ameritron P/N D101, 102, 114, 115 1N34A 300-0346 D103 1N752 Zener 5.6V 305-0710 D116 - 120 1N4001 300-0266 D104 - 113 1N5408 300-0145 C101 27 pF 500 V. • C214 150pF capacitor 208-5151 C215 220pF capacitor 2085171 L201 See input chart See input chart S201 Input switch 500-4811 AL-800H Tuned Input Chart BAND C201 (pF) tube side L201 C201 (pF) transmitter side 2700 (208-5689)* 21.75 (405-1217) 2000 (208-5608) 1300 (208-5177) 18.75. • AL-800H Instruction Manual Timer / Overload Board (50-0117-2) Designator Description Ameritron P/N C501-506.01 uF 50 V disc 200-0416 C507,508.47 uF tantalum 203-0530 C509 100 uF 25 V 203-0564 D501, 502 1N4001 300-0266 D503 5.6 V zener 301-710 IC501.

• AL-800H Instruction Manual AL-800H Main Chassis Parts List Designator Description Ameritron P/N Blower (Howard 3-90-8538) 410-3590 C1, 6 170 pF Doorknob 7.5 kV 209-0559 C2, 3, 9, 20.001 uF 7.5 kV 200-7224 C4, 5 470 pF 3 kV chip capacitor. • AL-800H Instruction Manual Frequency Coverage AL-800H AL-800HX 160 meters 1.8-2.0 MHz 160 meters 1.8-2.0 MHz 80 meters 3.3-4.4 MHz 80 meters 3.3-4.4 MHz 40 meters 6.3-8.3 MHz 40 meters 6.3-8.3 MHz 20 meters 10.1-15.5 MHz 20 meters 10.1-15.5 MHz 15 meters 16.5-21.5 MHz*. • AL-800H Instruction Manual Notes.

I have a Ameritron AL-811 that has been converted to use 572B tubes. When I got it it would only do 100 watts so I replaced the tubes, let it sit on stand by for a day and then it would do 800 watts for a while. But after a little while it would start dropping off on power so I let it sit on stand by for several days and everytime I checked it it would be doing less power and now it only does about 80 watts. So does it make sense that it could go through tubes just sitting on stand? And why would it do that? Could it be that the power supply voltage is too high? I think the voltage sits around 1800 volts according to the meter, but I'd have to check to make sure.

The 572b tubes are a very durable transmitting tube. You have to be very mean to them to make them go south. 1800 volts is probably the minimum you would want to run them at, they run better at around 2500.

Check your idling current on the plates. To do this key the amplifier with no carrier or RF input. You should see around 90 milliamps of current. Then check the current at full output.

You should see about 500 milliamps, which is a reference which you should not exceed. Watch the high voltage at full out and make sure it is not dropping to low, 300-400 volts drop is about right depending on how stout the transformer is. These are all things to look for if your amp is working normally. Maybe some else will jump in with some other pointers too. 73 Ed KC0PZE. With 1800 volts and 500mA plate current those 572B's should show no color on the plates whatsoever under keydown conditions.In standby mode they should last a lifetime.As Ed said,check the bias.If it is too high the tubes will draw too much current but should still not be damaged.I would be suspicious of something in the power supply causing a drop in plate voltage but it must be awfully low to cause only 60-80 watts output.How many watts are you driving it with and is it being tuned and loaded properly? Okay, I checked it out last night and here are my results, everything was done into a dummy load with a bird 43, with 10 watts carrier in on am I got 40 watts out, plate current-75ma grid current-30ma.

Voltage without a carrier is 1800 and voltage with 10 watts in, 40 out was down to 1700. Increasing the drive to 25 watts got 60 watts out but the grid current won't go over 80ma and the plate current won't go over 35ma. I tried it on various bands from 10-160 meters with the same results or at least close to. This is about the same way it acted before with the old tubes, then when I replaced them everything worked the way it should for a while. Does this sound like the bias is off and needs adjustment? Thanks for all the help. Ameritron 811A The bias is established by the diodes D19 thru D24 in the B-minus lead (center-tap of the filament transformer).

Check the diodes; they should all be the same. Looking at the schematic, point W6 (B-minus) is connected to W5 when the relay RLY-1B closes. B-minus continues up thru S-4 (this switch could be flakey), thru the current meter, M1. R-10 is a 330 ohm resistor in series with the negative side of the meter (make sure it’s good) and, finally you have a 0.6 ohm resistor R-9 between B-minus and chassis ground. I am not sure how the conversion to 572B’s were done; are there any resistors on the tube sockets themselves (maybe 47 ohms at 2 watts?), if so check value of all and make sure that they all are connected. I cannot believe that the amplifier is eating tube with 1800 volts and no color showing; something is stopping you from drawing current. Replace the DC Blocking capacitor, C-13..

That amp should not require any mods to convert to 572B's.572B's are like 811A's on steroids.Electrically the same but with 160 watts plate dissapation instead of the 65 watts for an 811A. Scarlet Diva Movie Torrent Download more. I'm confused by a couple of your statments: First you said: Okay, I checked it out last night and here are my results, everything was done into a dummy load with a bird 43, with 10 watts carrier in on am I got 40 watts out, plate current-75ma grid current-30ma.

Then you said: increasing the drive to 25 watts got 60 watts out but the grid current won't go over 80ma and the plate current won't go over 35ma. Are you sure that is right because more power output should result in more plate current,not less.Either way something is wrong with the bias because the plate meter should read around 110mA +/- 25% (according to the manual) with the amp switched inline and with no drive applied. Try reducing the loading control somewhat and see if that raises the grid current.It may be loaded too heavily. Check R12 and R13 in the ALC circuit as well as the setting of R14 which is the ALC adjust pot.If it is set wrong it will limit the amount of drive from the radio regardless of what the radio is set at.That is of course if you have the ALC line connected to your driver radio.

After that:?::?. Uh, you're not running this from a 120-Volt 15-Amp outlet, are you? With adequate filament voltage on that tube, a 572B should last more or less forever in that box. It's like running a box meant for the 572B on 'low' side all the time. If you're running it on 120 Volts, and the outlet circuit isn't stout enough, you'll see the color of the filaments inside, dim noticeably with full drive. This would indicate that the line voltage was falling under load, causing the 6.3 Volts on the filaments to fall, as well. This dimming of the yellow-white filament color indicates that the filament temperature is falling.

Running that filament at too low a temperature can and will cause the tube to go 'soft', and appear to be worn out and weak. If this is in fact the root of the trouble, you won't see those filaments dim when you key it now. If you remember seeing that happen when they were 'fresh', that would be a clue.

And if you're running it from a stout 240-Volt circuit, this is probably not the cause. Click to expand.I'm glad we have a handle on the situation however, I have a problem with this conversion; there are circuit differences in the amps constructed to run 572B's and the amps constructed to run 811's 572B amps All the 572B amps have a grid leak resistor in the control grid circuit to provide 'self bias' for the tube. 811A Amps The 811 circuit has the control grid grounded; if a 572B tube is put in that circuit without the proper modifications done for the grid leak resistors then that tube (the 572B) IS gonna draw more current than it should and it's gonna draw current when it should n't. When the RF sensing keyer was put in there I wonder what was done to the center point of the filament circuit; I wonder if it is still switched thru a relay or is it hard grounded. I wonder why it was only doing 100 watts when it was sold to him?. I predict that the damage has been done to that set of tubes.

Just changing the line voltage will NOT undo the damage. Might have prevented it, had you done so in the first place. You can run 120 Volts, so long as you hold the drive down to about half-throttle. If you draw less current from the wall, the voltage drop won't be that bad. A 20-Amp 120-Volt circuit will be wired with #12 wire. A 15-Amp circuit with #14, usually.

The fatter wire will have a smaller voltage drop at the same current draw. The reason the problem is worse on a 120-Volt circuit is that you need TWICE the amperage on a 120-Volt circuit as you need on the 240. This causes twice the voltage drop in the same size wire, for the same output wattage on the linear. Turn the drive down, and the current demand drops with it. So does the voltage drop on the outlet wiring. If the 811A tubes haven't had this same (mis)treatment yet, try them on a 240-Volt circuit, if you can.

Or hold back to about half of full power. Either strategy will work.

The old textbooks describe a procedure to 'rejuvenate' the thoriated-tungsten cathode in a tube like that. I have had pretty poor results on the ones I have tried to bring back to life. Mostly it involves turning up the filament voltage on a test rig. More often than not, the filament just burns out. You DO have to blow air on them when trying this trick. The heat from the filament alone gets out of hand when you turn up the filament voltage, even for 15 or 20 minutes.

If you placed larger wires in the wall, and fed your 120-Volt outlet with #8 or #6 wire, the problem would be partly fixed. Trouble is, most building codes forbid using wire larger than #12 for a 120-Volt circuit. Might void your homeowner's insurance if they discovered it after a house fire. Besides, wire that large won't fit under the screws on a 120-Volt outlet. Here's hoping the 811A tubes haven't been 'flattened' yet.