lost_manuals_Barker_and_Williamson--LPS-1--service--ID4302 INSTRUCTION BOOK FOR MODEL LPA-1 LINEAR POWER AMPLIFIER AND MODEL LPS-1 POWER SUPPLY BARKER & WILLIAMSON, INC BRISTOL, PENNSYLVANIA F IG U R E I. M O D E L L P A -I L IN E A R P O W E R A M P L IF IE R A N D M O D E L L P S -I P O W E R S U P P L Y CONTESTS rage Important Warning i SECTION 1. Model LPA-1 Linear Power Amplifier 1 SECTION 2. Model LPS-1 Power Supply 9 SECTION 3. Maintenance and Trouble Shooting 11 SECTION it. Parts Lists 16 Warranty 18 ILLUSTRATIONS Figure No• Title 1 Model LPA-1 Linear Power Amplifier and Model LPS-1 Power Supply 2 Model LPA-1 Linear Power Amplifier, Top of Chassis 3 Model LPS-1 Power'Supply, Top of Chassis U Model LPS-1 Power Supply, Bottom of Chassis 5A Connection of LPA-1 to LPS-1 5>B Connections for CW and Linear AM Operation SO Connections for SSB, SSB with Carrier and DSB Operation SB Bias Connection of LPA-1 6 Schematic Diagram, LPA-1 Linear Power Amplifier 7 Schematic Diagram, LPS-1 Power Supply IMPORTANT WARNING- ... MISUNDERSTANDING OF FUNCTION AND MISUSE OF THIS EQUIPMENT MAY RESULT IN DAMAGE, MALFUNCTION OR BOTH. THIS EQUIPMENT HAS BEEN FACTOHX-TESTED UNDER ACTUAL OPERATING CONDITIONS FOR AN EXTENDED PERIOD ON ALL BANDS, BEFORE IT WAS PLACED IN ITS CARTON. THE TUBES FURNISHED ARE THOSE ACTUALLY USED IN THE OPERATIONAL TEST. THEY WERE ALL UP TO STANDARD PERFORMANCE WHEN PACKED AND SHIPPED FROM THE FACTORY. OPERATION OF THIS EQUIPMENT IN A MANNER OTHER THAN GIVEN IN STEP-BY-STEP FORM IN THE MANUAL IS AT THE RISK OF THE OWNER. FACTORY WARRANTY ON PARTS, TUBES AND TRANSFORMERS WILL BE VOIDED WHEN THE FACTORY RECOGNIZES THAT EQUIP¬ MENT RETURNED FOR WARRANTY REPAIRS HAS BEEN SUBJECTED TO MISUSE. HERE ARE A FEW DON'TS THAT EVERY OPERATOR SHOULD OBSERVE: 1. DON'T ATTEMPT TO CONNECT THE AC POWER TERMINALS TO THE POWER LINE, UNLESS YOU ARE THOROUGHLY FAMILIAR WITH THE FUNCTION OF ALL CONTROL KNOBS AND SWITCHES. 2. DON'T TURN POWER ON, UNLESS ALL TUBES ARE IN PROPER SOCKETS AND EQUIPMENT IS CONNECTED TO AN APPROPRIATE ANTENNA FOR THE BAND IN USE OR A NON-INDUCTIVE DUMMY LOAD. 3. DON'T ALLOW THE EQUIPMENT TO OPERATE IN A NON-RESONANT CONDITION - TO DO SO WILL RESULT IN DAMAGED TUBES. It. DON'T ATTEMPT TO OPERATE THE EQUIPMENT WITH IMPROPER BIAS. SET BIAS IN CONFORMANCE WITH MANUAL INSTRUCTIONS. 5. DON'T USE UNDER-SIZE PRIMARY AC LINE WIRE - USE #llt OR LARGER WIRE FOR CONNECTION TO AC LINE. 6. DON'T DRIVE THE FINAL PLATE MILS ON VOICE PEAKS TO A METER VALUE GREATER THAN l£0 TO 180 MA. SEE INSTRUCTION MANUAL UNDER SSB OPERATION. SHIPPING DAMAGE i ini.. | I | I III ■ II ■! Ml || i ■ ii ■ i ■! ■> WHERE EQUIPMENT HAS BEEN DAMAGED IN SHIPMENT, AN IMMEDIATE CLAIM SHOULD BE FILED WITH THE CARRIER WHO MADE DELIVERY TO YOUR PREMISES, OR YOUR DISTRIBUTOR. OUR COMPANY IS NOT RESPONSIBLE FOR SHIPPING DAMAGE. X*" Section 1. Model LPA-1 Linear Power Amplifier Note: It is recommended that the user read, and reread, this instruction book until all connections, controls and functions are clearly understood. You will derive more pleasure from your equipment if you are familiar with its correct operation. 1. General a. The B&W Model LPA-1 Linear Power Amplifier (fig. 1) is designed for desk-top operation. Full legal input power is easily obtained for CW and SSB emission. Linear AM operation is limited to within the dissipation ratings of the power amplifier tubes 4 to V <1 e y ^ to Q / l/j b. The Model LPA-1 Linear Power Amplifier has a self-contained filament and bias supply for the power amplifier tubes. A companion power supply, B&W Model LPS-1 Power Supply, (fig. 3;) was designed to furnish the high voltage, power controls and protection circuits for the most efficient oper¬ ation of the amplifier, although any well designed and constructed power supply that will furnish the required high voltage and current, may be used. CAUTION: The metering circuit of the Model LPA-1 Linear Power Amplifier requires that the NEGATIVE POWER SUPPLY LEAD MUST BE INSULATED FROM CHASSIS GROUND. . ili>pi— WARNING THE MODEL LPA-1 CHASSIS MUST BE BONDED TO THE MODEL LPS-1 POWER SUPPLY CHASSIS, OR THE POWER SUPPLY CHASSIS IN USE, TO INSURE A GOOD GROUND RETURN PATH BETWEEN THE UNITS. c. The B&W Model LPA-1 Linear Power Amplifier is shipped in a baffled and padded fibreboard container. The instruction book and two (2) separately wrapped type 813 beam power tubes are included in the container. The user should make sure that the equipment has not been damaged in shipment before making any connections to the unit. If shipping damage is found, notify your distributor at once. d. B&W Model LPA-1 Linear Power Amplifier has been carefully inspected, tested and adjusted at the factory to assure unlimited, trouble-free operation. 2. Installation and Connections a. Carefully remove the Model LPA-1 Linear Power Amplifier from the fibreboard.shipping container and remove all reinforcing pieces. b. . Open the cabinet lid and remove the instruction book and the two (2) :type 813 beam power tubes. * u&'e ^ -* ''**1 0 S** ft**. k u -1- 2o Installation and Connections (continued) Read the instruction book d Install the two (2) type 813 beam power tubes in their' sockets. Connect a plate cap to each tube 0 Connect the Model I-PA-1 amplifier to a power supply (B&W Model LPS-1 Power Supply is recommended) as shown in figure 5>A. WARNING DANGEROUS HIGH VOLTAGE IS PRESENT IN ANY POWER SUPPLY. USE EXTREME CARE WHEN MAKING CONNECTIONS AND USING SUCH A SUPPLY BE SAFE f „ Turn the power supply switch to the on position (do not apply voltage to the amplifier yet) and make sure the filaments of the type beam-power tubes light and that'the blower motor is running. high 813 g. Turn the power s uppl; . i swit c h to the TUNE (reduced high voltage) position to' check the high voltage supply circuits h. running Turn off the power supply and observe that the blower motor stops . -h i. ' Locate the Model I,PA-1. Linear Power Amplifier as near as possible to the driving transmitter (B&W Model 5100-B with Model 51SB-B recommended) and allow adequate free space on all sides for air circulation and efficient Do not place any accessories or equipment on top of the amplifier or transmitter cabinets„ blower operation 3 Antenna Systems a The Model LPA-1 Linear Power Amplifier is designed with a nominal 52 or 75 ohm unbalanced output1 circuit which will feed a variety of antenna systemso Antenna systems of ether nominal impedance may be used, however, if they are transformed' id 52 hr 75 ohms unbalanced at the amplifier termination. Great 'care should be expended in keeping the VSWR of the antenna feed line as low as possible (l,.5>sl or less) because of the high rf voltages present. A well matched, low VSWR feed line will'reward the user with greater amplifier efficiency and more power into the antenna. b. Recommended, antenna systems way be found in the instruction book for the B&¥ Model 5100-B Transmit tor . The Radio Amateur’s Handbook and the A.R.R.L. Antenna Handbook h Controls a All operating controls of the Model LPA-1 Linear Power Amplifier are located on the recessed front panel and perform the following functions! iu Controls (continued) H MND 10,15,20,1*0,80 TUNE 0 through 10 LOAD 0 through 10 BIAS GRID-PLATE switch 5. General Operation Changes taps (inductance) of final tank coil and is mechanically linked to a switch arm on the tank tuning capacitor to select A proper capacitance for the band in operation. Controls the adjustment of the tank tuning capacitor so that the plate tank circuit may be tuned to resonance (minimum meter reading or dip). Controls the adjustment of the output loading capacitor for proper loading of the amplifier output• Controls the output voltage of the bias ■i supply for the proper operating bias voltage applied to the power amplifier tubes. Connects the panel meter into the grid or plate circuit for monitoring drive, plate, loading and bias current of the power amplifier tubes. Make all connections to the Model LPA-1 Linear Power Amplifier as shown in the figure for the desired mode of operation. A dummy load, suitable for the frequency and the power output, is recommended while making the initial adjustments ^o the amplifier. If a dummy load is not available, a well matched antenna"-may be used. h I ' , ■ 6. CW Operation (fig. f>B) a. Make sure that the driving transmitter and the Model LPA-1 Linear Power Amplifier are both adjusted to the same frequency band. b. Turn on the filament and low voltage to the driving transmitter. Make sure the high voltage is turned off* c. Place the meter switch of the LPA-1 in the PLATE position and the power supply switch "in the ON position. Allow 30 seconds for the tube fila ments to warm up. ¥ d. Turn the power supply switch to the OPERATE (full high voltage) position and -^0^ ■ pj.9 *b 6 ^ *-■■■■ e* b' # e. Turn the power supply switch to the ON position and the meter switch of the LPA-1 to the GRID position. -3- 6. CW Operation (fig. 5B) (continued) f. Apply high voltage to the driving transmitter (filaments and low voltage on) and close the keying circuit. g. Tune and load the driving transmitter to obtain a grid current reading of 80 to 90 ma on the LPA-1 panel meter. h. Place the meter switch of the LPA-1 in the PLATE position, the LOAD control on zero (0) and adjust the TUNE control for minimum deflection of the panel meter. i. Turn power supply switch to the TUNE (reduced high voltage) position and adjust the LPA-1 TUNE and LOAD controls for a reading of 175 ma on the panel meter. Each time the LOAD control is adjusted, make sure the TUNE control is adjusted for minimum current reading on the panel meter. j. Turn the power supply switch to the OPERATE (full high voltage) position: and readjust the TUNE and LOAD controls of the LPA-1 for a reading of 1*00 ma on the panel meter, using the method described in subparagraph i above. The grid current should be then checked and readjusted to 80 to 90 ma. k. Open the keying circuit of the driving transmitter, and the-Model LPA-1 is ready for CW operation. Note: When changing from a dummy load to an antenna system, the Model LPA-1 will usually require slight readjustment of the TUNE and LOAD controls. i 7'. SSB Operation (fig. 5©) Note: The following instructions are based on using a B&W Model 5100-B Transmitter and a B&W Model 51SB-B Single Sideband Generator to drive the Model LPA-1 Linear Power Amplifier. If other equipment is used to drive the Model LPA-1, these instructions should be modified for the equip¬ ment in use. a. Refer to paragraph 5 for amplifier load information. * b. Make sure that the 5100-B transmitter, the 51SB-B sideband generator and the LPA-1 amplifier are all adjusted to the same frequency band. c. Turn on the filament and low voltage to the 5100-B transmitter (Model 51SB-B takes its power from Model 5100B). Make sure the high voltage on 5100-B is turned off*, d. Place the meter switch of the LPA-1 in the PLATE position and the power supply switch in the ON position. Allow 30! seconds for the tube filaments to warm up. 7. SSB Operation (continued) e. Turn the power supply switch to the OPERATE (full high vo'ltagej * f. Turn the power supply switch to the ON position* g. Adjust the controls of the 5100-B for CW operation (refer to 5100-B Instruction Manual) and tune and load the transmitter in a normal manner. Keep the 5100-B in operation. Adjust the 5100B for 80 to 90 ma drive to the LPA-1. h. Turn the power supply switch to the TUNE (reduced high voltage) position and adjust the LPA-1 TUNE and LOAD controls for a reading of 175 ma on the panel meter. Be sure to readjust the TUNE control for minimum meter reading each time the LOAD control, is adjusted. i. Turn the power supply switch to the OPERATE (full high voltage) position and readjust the. LPA-1 TUNE and LOAD controls for a reading of i|.00 ma on the panel meter. Again, make sure to adjust the TUNE control for minimum meter reading each time the LOAD control is adjusted until the correct plate current (400 ma) is obtained. j. Place the LPA-1 meter switch in the GRID position and observe that the drive from the 5100-B transmitter is between 80 and 90 ma, depending upon the operating frequency, k. Place the LPA-1 meter switch in the PLATE position, turn the power supply switch to the ON position and turn off the high voltage to the 5100-B transmitter. l. Place the BALANGE-UNBALA1CE switch of the Model 51SB-B sideband generator in the UNBALANCE position, the TUNE-OPERATE switch in the TUNE position, the AUDIO GAIN control in the full counterclockwise (off) position and the METER switch in the GRID position. m. Turn the 5100-B NORM-SSB switch to the SSB position and turn on the high voltage to the transmitter. n. Adjust the 51SB-B DRIVER TUNING and BAL. MOD. TUNING controls for maximum reading on the generator panel meter. o. Adjust the 5100-B EXCITATION CONTROL (and the MULTIPLIER TUNING control if necessary) for a reading of 0.5 ma on the 51SB-B panel meter. % ■ ■ p. Place the 51SB-B BALANCE-UNBALANCE switch in the BALANCE position and the METER switch in the OUTPUT position. q. Adjust the two balance controls of the 51SB-B generator until the panel meter reads zero. (When the 51SB-B panel meter reads zero, the carrier is completely balanced out.) -5 7. SSB Operation (continued) r. Place the 51SB-B TUNE-OPERATE switch in the OPERATE position and the METER switch in the GRID position. s. Turn the power supply switch to the TUNE (reduced high voltage) position and then to the OPERATE (full high voltage) position. t. While speaking normally into the microphone, adjust the 51SB-B AUDIO GAIN control until the panel meter on £lSB-B barely kicks upward from zero to-not more than two small divisions on the scale, on voice peaks. The PLATE meter on the LPA-1 should not exceed a reading of 150 to 180 ma on voice peaks. u. The equipments are now properly adjusted for SSB operation. Note; If a dummy load was used for making the above adjustments, turn off the high voltage on the 5100-B transmitter and turn the power supply switch to the ON position. Disconnect the dummy load and connect the proper antenna to the output connector of the LPA-1 amplifier. Return the 5100-B transmitter to the CW control ‘adjustments and repeat the steps in paragraphs ? g through s. 8. SSB with Carrier Operation (fig. 5>C) Note: The upper or lower sideband may be operated by placing the SIDEBAND, UPPER-LOWER switch of the 51SB-B in the desired sideband position. a. Refer to paragraph 5 for amplifier load information. b. Make sure the driving transmitter, sideband generator and the LPA-1 amplifier are adjusted to the same frequency band. c. Turn on the filament and low voltage to the 5100-B transmitter (Model 51SB-B takes its poi*er from the Model f>100-B). Make sure the high voltage is turned off on the $100-B transmitter. d. Place the meter switch of the LPA-1 in the PLATE position and the power supply switch in the ON position. Allow 30 seconds for the tube filaments to warm up. e. Turn the power supply switch to the OPERATE (full high voltage) position and adjust the LPA-1 BIAS control for a reading of hO ma on the panel meter. f. Turn the power supply switch to the ON position and the meter switch of the LPA-1 to the GRID position. 6- 8. SSB with Carrier Operation (continued) g. . Place the BALA.NCE~UNBALA.NCE switch of the 51SB-B sideband generator in the UNBALANCE position and the TUNE-OPERATE switch in the TUNE position. h. Turn on the high voltage of the 5100-B transmitter and tune and load the driving transmitter and sideband generator for a reading of 80-90 ma on the LEA-1 panel meter. i. Turn the power supply switch to the TUNE (reduced high voltage) position and adjust the TUNE and LOAD controls of the LPA-1 for a reading of l£0 ma on the panel meter (see subparagraph 6i). j. Turn the power supply switch to the OPERATE (full high voltage) position and readjust the TUNE and LOAD controls of the LPA-1 for a reading of 300 ma on the panel meter. k. Place the BALANCE-UNBALANCE switch of the 51SB-B generator in the BALANCE position and adjust the two balance controls for a zero (o) reading on the 51SB-B panel meter. l. Readjust either of the two balance controls of the 51SB-B for a reading of 15>0 ma on the Model LPA-1 panel meter. m. Adjust the AUDIO GAIN control of the 51SB-B while speaking normally into the microphone until the LPA-1 panel meter needle just moves slightly in an upward direction. "■ i CAUTION: Overmodulation with distortion.will occur if the LPA-1 panel meter indicates an increase of more than 5% when speaking into the microphone. 9. DSB with Carrier Operation (fig. 58) a. Repeat the steps in paragraphs8a through k. b. Turn off the high voltage to all equipments. c. Remove the balanced modulator tube V101 from the 51SB-B sideband generator, d. Turn on the high voltage to all equipments. e. Readjust the left hand balance control of the 5ISB-B for a reading of 150 ma on .the LPA-1 panel meter. f. Repeat the step in paragraph 8m and observe the Caution note. -7 10. Linear AM Operation (fig. 5B) Note: The B&L'J Model LPA-1 Linear Power Amplifier can easily be driven to full linear am output power by an am1 transmitter capable of 25 to 30 watts output. When the 3W Model 5100-B Transmitter or another of similiar .output is used as the am driving transmitter, the-power output must be reduced to 25 to 30 watts. a. Refer to paragraph 5 for amplifier load information. b. Make sure that the AM driving transmitter and the LPA-1 are adjusted to the same frequency band, c. Turn on the filament and low voltage to the driving transmitter. Make sure the high voltage is turned off the driving transmitter. d. Place the meter switch of the LPA-1 in the PLATE position and the power supply switch in the ON position. Allow 3.0.seconds for the tube fila¬ ments to warm up. e. Turn the power supply switch to the OPERATE (full high voltage) position and adjust the LPA-1 BIAS control SoT'-g—rshading* uP Eo ma dl the panel taotorrv f. Turn the power.supply .to the ON position and the meter switch o£> the 1 LPA-1 to the GRID position.. g„ Turn on the high voltage to the am driving transmitter (adjusted for am operation) and tune^and load for maximum reading on the. LPA-1 panel meter. h r 4 h n h. Place the meter , switch ofi the LPA-1 in the PLATE position and turn the power supply switch to the TUNE (reduced high voltage) position. i. Adjust the LPA-1 TUNE and LOAD controls for a reading of 150 ma on the panel meter. j. Turn the power supply switch to the OPERATE (full high voltage) position and adjust the AM driving transmitter output for a reading of 300 ma on the LPA-1 panel meter. ’ ^ k. Speaking (normally) into the microphone, adjust the AUDIO GAIN control of- "the driving transmitter to the point where the plate current of the LPA-1 barely changes on voice peaks. p CAUTION: Overmodulation with distortion, will occur if the * -r ■' LPA-1 panel meter indicates an increase of more than 5% when speaking into the. microphone. 8- Section 2. Model LPS-1 Power Supply WARNING DANGEROUS HIGH VOLTAGE IS PRESENT WHEN THIS POWER SUPPLY IS TURNED ON CAUTION: Do not turn this power supply on without a it L ■ ■ suitable load being connected to the output terminals. 11. General a. The B , ^ ' WARNING , ► MIKE SURE THAT ALL POWER LEADS ARE DISCONNECTED FROM THE MODEL LPA-1 BEFORE ANY MAINTENANCE WORK IS AT TEMPTED. BE SAFE I (1) Remove the type 813 tubes from their sockets and inspect the pins for signs of heating caused by defective socket contact. Removing and replacing the tubes in their sockets cleans the tube pins and socket contacts. Glean bulbs and bases and reinstall. (2) Carefully clean tank coil, both variable capacitors and all chassis surfaces with a soft brush. If dirt or dust sticks to the chassis or components, use a small amount of carbon- tetrachloride. (3) Apply three or four drops of light machine oil in each of the two oiling tubes of the blower motor. Make sure the blower rotates freely. H (ii) Apply a small amount of "Lubriplate11 around ball detent holes of the tank coil and the mechanical link arms of the coil and h ■ tuning'^ capacitor. (5) Inspect all screws, nuts, components and wire connections, * making sure they are tight and in good condition. p j h b. To remove the Model LPA-1 Linear Power Amplifier from its case, ~ proceed as follows: (1) Remove the screws from the four feet on the bottom of the large chassis-, The short feet are located at the rear and the longer feet are located at the front. - i ■ * i ‘ * " ‘ (2) Lift the cabinet lid and remove the two screws from the weld studs located along the top inside edge of the front panel,. p 1 L ■ (3) Remove the three screws located along the rear edge and the three screws located along the front edge on the bottom of the cabinet. -11- lit. Maintenance (continued) (it) Carefully slide the amplifier from its case. (5>) To reassemble, reverse the above steps, being careful not to damage any parts. c. To remove the tube chassis from the main chassis, first remove the main chassis from the case and proceed as follows: (1) Remove the plate caps from the type 813 tubes. (2) Disconnect the blower plug from the tube chassis receptacle. (3) Remove the BIAS control knob. (h) Remove the two nuts from the meter terminals and remove the resistor assembly board from the meter. ($) Remove the BIAS control potentiometer from the front panel. (6) Remove the meter switch from the front panel (keep the switch terminals toward the top of the panel when reassembling so meter will ’read correct GRID or PLATE current). (7) Remove the large (l/U x 20) screw in the top of the plate choke. (8) Hold the tube chassis. Remove the seven screws which secure the tube chassis to the main chassis. (9) To reassemble, reverse the above steps, being careful not to damage any of the components. 1$. Trouble Shooting and Repair The following chart lists the common causes of trouble. It is not intended to be all inclusive but to serve only as a guide in helping to locate the trouble. Refer to the schematic diagrams, figures 6 and 7 for the Model LPA-1 and LPS-1 respectively. WARNING DANGEROUS HIGH VOLTAGE IS PRESENT IN AN! POWER SUPPLY OR EQUIPMENT THAT IS TURNED ON. USE EXTREME CARE WHEN TROUBLE SHOOTING EQUIPMENT UNDER POWER ON CONDITIONS. CAUTION: Do not use a fuse rated at more than 15 amperes in the power supply. 12- 1$, Trouble Shooting and Repair (continued) Symptom Completely inoperative Model LPA-1. Check I Cause and Remedy 1151 v, 60 cycle input j No voltage. Replace voltage primary fuse .Repair or connect primary power mains. Panel meter reads off scale Fuse blows . Fuse F101 Type 813 tubes Transformers T101.T201 Fus e,F101 Type 813 tubes Capacitors C205 through C209 Blown fuse F101. Replace. USE ONLY A IgA, 125V FUSE. Shorted tube fila¬ ment. Replace tube (or tubes). Shorted transformer T101 or T201. Replace. Wrong value fuse F101. Replace, USE ONLY A 15a, 125Ouse. Tube glows blue. Replace. Shorted or lealqr capacitor C205 through C209* Replace Fuse blows. Panel meter reads normal. Fuse F101 Type 813 tubes Transformers T101, T102 Wrong value fuse F101. Replace. USE ONLY A ISA,125V FUSE Defective tube. Replace. Shorted transformer T101 or T102 .Replace Capacitors C101 through C108 Faulty capacitor C101 through C108.Replace. Resistors R101 through R108 Defective resistor R101 thr ou gh R108. Replace. Section 1*. Parts Lists (continued) ■ i Symbol C101 thru C108 C109 C110 cm, C112 C113 ' / L101 ,1102 thru LlOii L105 R101 thru R108 RIO? R110 SW101 n l,,h J'T1- r T101 T102 F101 PL101 V101 thru VIOL. . Model LPS-1 Power p- , J Description B&W Number Capacitor, electrolytic, 80 mf, UOO v H r ■ ■■ 1 _ ■ 1 r 1 1 ■ ■■ r h J # 1 ,1 Jk. *lrih ■ ■■ . h Capacitor, paper, .1 mf, 3 kv ■ 4 r 4 A l Capacitor, ceramic, *001 mf, 5 kv " Capacitor, feed-thru, ac line 1 ■ 1 - i Capacitor, disk, .01 mf, 600 v H 4 Choke, filter • - ■■ . 1 rL * Choke> rf i * _ * - / ■' *• ■ ■- "p Choke, rf, 1 mh, ij.00 ma / 1 ■ j ■ fc ' ' * Resistor, wirewound, 20 K ohms, 20 w J *■ k&3 -1 1*5 0 7 -63 1*55 2 -1 , y k. 1*525-21 ■ 5120U s 50359 x-371 k ■ 1*1*31—12 - P f " Resistor, cone heater type, 1000 w, 115 v 5ll*05 • ■ + , - : 1 Resistor, compos it ion* 100 K ohms, l/2 w li01-10l*K Switch, power • - ■ ■ * * ■ T . ■ ■ - 1 * ■ ■ - k | r. . - : - 1 . ■ 1 , - j. r - ■ -fc Transformer, plat Transformer, filament Fuse, 15 amp, 125 v Lamp, bayonet type, 6,3 v, 300 ma Tube, type 8l6 Cable assembly 5ll*0l* ’ ’ ■ ■ : _ p p 51U81 511*80 5201-7 1*716-16 8l6 5ll*93 AC power cord 51259 -17- 1$, Trouble Shooting and Repair (continued) Symptom .. — " ....1 Check Cause and Remedy No grid drive. Capacitors G202, Open or shorted capacitors C203, C20I4. C202, C203,C2Q4. Replace. Variable resistor Defective variable resistor R202 R202. Replace. RF choke L201 ' Open or shorted rf choke L201. Replace. Excessive drop in grid Type 813 tubes Low filament emission of drive when high volt- type 0I3 tube (tubes)* age is applied. Replace. Note: Normal grid drop for SSB opera- tion is approx- imately 2$%. No plate current. Filter choke L101 Open filter choke L101. Replace. ' Plate choke L202 1 Open plate choke L202. ■ Replace. RF choke L203 Open rf choke L203.Replace. . Arc-over in variable Variable capacitors Dirt or other material capsciijOr • 0210,0211 between capacitor plates. Clean. Rf choke L205 Open or shorted rf choke J L205. Replace, Antenna system High VSWR condition or a defect in the antenna sys¬ tem. Adjust for a VSWR of 1.5:1 or less. Repair fault. 1 I i 1 15, Trouble Shooting and Repair (continued) Symptom Will not tune when adjusted to same band as driving transmitter. Check Mechanical linkage, between coil L20U and capacitor C210 Cause and Remedy Defective adjustment in mechanical linkage between tank coil L20U and variable capacitor C210. Adjust so the switch arm on capacitor C210 shorts both the front and rear sections when coil L20l|. is adjusted to both lj.0 and 80 meters. When coil L20U is adjusted to 10, 15 or 20 meters the capacitor C210 switch arm should be open. -15- Section b. Parts Lists Model LPA-1 Linear Power Amplifier Symbol Description 1 1 11 * 1-1 * . n . B&W Number C201, C215, 4 0202^0212,0213 > 0216 Capacitorj disk, .01 mf, 600 v 14.525-21 C20U Capacitor, disk, .001 mf, 500 v U525-20 C205 thru 0209 ■r Capacitor, ceramic, ,001 mf, 5 kv il.552-1 C210 Capacitor, variable, air 512U2. C211 i Capacitor, variable, air 512141 C21U 1 ■ i Capacitor, electrolytic, ItO-UO mf, 150 V U553-6 CR201 Rectifier, selenium, 130 v, 65 ma 51253 L201 Choke, rf, 500 uh, 100 ma 50711 L202 Choke, rf, plate x-368 L203, L205 Choke, rf, 1 mh, ij.00 ma x-37i L2.0U Coil, pi-network Model 850A R201 Resistor, wirewound, 500 ohms,5 w UU31-8 R202 Resistor, variable, 500 ohmSj^'w 9~ Resistor, shunt, 5 ohms +1%,sk'vr I4I4I9-IU R203, R20i| I4I4O9-27 R205 Resistor, series, 2hh$ ohms ±l$,l/2 to U1425-56 M2 01 Meter, 0-500 ma DC scale 5103-1 SW201 B201 J0J xol T201 Switch, toggle, SPDT ^ it { j&t5TiAi€^ / Blower, 115 v AC, 60 cycle Transformer, filament Ii600-5 SiS&S 51255,. 51206 T202 Choke, filament 51177 J201 Receptacle, rf 5085 J202 Receptacle and cable assembly 511*01 V201, , V202 Tube, type 813 + 813 -16- Note: Beam Power tubes of the 813 type, when new or after prolonged storage, will occasionally flash over when plate voltage is first applied. This is due to residual gas in the tube which is eliminated by the flashcver* This condition will not recur during normal operation. ^ ; \ STANDARD WARRANTY Adopted and Recommended by the Radio-Electronics-Television Manufacturers Association P ► Barker & Williamson, Inc. warrants each new radio product manufactured by it to be free from defective material and workmanship and agrees to remedy any such defect or to furnish a new part in exchange for any part of any unit of its manufacture which under NORMAL INSTALLATION, USE and SERVICE discloses such defects, provided the unit is delivered by the owner, to our authorized dealer or wholesaler, from whom purchased, intact, for their examination, with all transportation charges prepaid. This warranty is valid, Only within 90 days from the date of purchase and is limited to new equipments. This warranty does not extend to any of our OUR IMPROPER .INSTALLATION, OR TO USE IN VIOLATION NOR EXTEND TO UNITS WHICH HAVE BEEN REPAIRED OR ALTERED OUTSIDE OF OUR TORY, NOR IN CASES WHERE THE SERIAL NUMBER THEREOF HAS BEEN REMOVED, DEFACED CHANGED. NOR TO ACCESSORIES'USED THEREWITH NOT OF OUR OWN MANUFACTURE. in no assume or implied- and other liability in connection with the sale of our radio'products. 18 ifi 0N F IG U R E 3. M O D E L L P S -I P O W E R S U P P L Y , T O P O F C H A S S IS <<<< o o o o 4^ oj ro — T B IO I C l 13 C II O IMHiM F IG U R E 4 . M O D E L L P S -I P O W E R S U P P L Y , B O T T O M O F C H A S S IS TB 10 / Z 2 O 4- CNP NOT £ ; CONNECT A LOAD TO L PA' L PS~f _ FfSURh SF A model LP5 - / Poa/ep supply pi Y AND THE Ac LINE TO THE connection of lpa- to lps~( re 20 / / 2 g 4-5 3 0 0 0 0 &*o H v MOPE i- L PA - t AMPL/T/ nspuf °urPU'i ..in t .. > mmiUMi ■ m ■ ■ ..*■ m v\ %v \ T TO A NT£tfMA OR PUMMY LOA P ■ N out rvi Moo EL S/oo - B tha tj 5 M / ttEE © © ® © ©j / 8 3 4- S' TB 'O/ ® 6/-,P Bv M O PE l L PS ~ / Pone Pi supply votE: CONNECT A LOAD To THE LPA ~ ! A UP TN E AC L/NE yo THE LP5-L _ Fop TEPM/NAL CONNECTIONS ON THE ElOO-D TP a NSMtrrep , Refer to the hi s tro cr/o v,- •• op CONNECTIONS Fop cw a NO L/ Ay e a R AM ope rat/OAT T3 2oi 0 * <* 10 ANTENNA OR Dummy l a a p 4 . * &N{? tfV AFO-O £ L L PA - / AWPll F/ER. \ PvT I o(s TP m i i tr S 3 4- S r& io i r "»V . m p. >-l * i J£^.i*h .. VI _ I^L Uf y■[ j (£> <*f> &*OfiV MODEL / P c - / pot/er Supply M OpE L St-56 -3 gene PA top Ou/PiJ T MODEL stoo - e> TP A NS M fTTE F l k-EG-3/u gR RG-m/o No T£: CONNECT A TO THE L PS lOA D TO TN F LEA~/ A A/D TEE A C L /ME ToP CO NN E CT/ ON S OA/ TEE St S& - g A A/D S/OO ~ TEA /vJ7 M / TTER , TEPEE To TE E /NS TROC T/O A/ 6 OOE CONNECT/OM FOR 5-5 3/ES3 P/frF CAPS/SR Aa/P OS 3 OPERA T/ON FlO USE SC T8 2o > / 2 3 4~ S _ Gnp H V/ model L P A - / A M PL / F/ER -1 NOTEi TERM/N A LS / AND Z ARE NORMALLY CONNECTED TOGETHE R For 6 rea 3- /A/ operas t/o a/ Remove ta/e Jumps And connect term/a/a lS jandZ NORMALLY' O PEA/ CONTACTS op t~A. to A PA /R O NORMALLY OPE A/ CON TA C TS O E ERE PO/OE ACTE A TEE RELAY TA/ TN E OR/VfMG TPANSM/TTES BtA COF/MEE / /OF/ OF FA FTGuRF SO. > 1 ^ Q © cQ k U1 Cl *"■ i »1 Cl Cl D vT) Q£ 111 U) Dt VD O u~ VJ VJ 3t Q “ VJ \S vj < O Cl Vi m O' < S a: Q. <1 ADDENDUM #1 LPa-1 Amplifier - LPS-1 Power Supply Certain design changes have "been incorporated in the LPA-1, serial Mo.251 and above, and all LPS-1 power supplies shipped from the factory after Mov. 1, i960. These changes will improve operating features, increase reliability and provide the ultimate in operator safety. AMPLIFIER ^HWI ■ fclHn I ^ ^ Bias control R202 has been replaced with an adjustable 500 ohm, 25 watt, wire- wound resistor and a single pole 2 position rotary switch SW202. These com¬ ponents are arranged such that correct operating static plate current is established for all modes of operation, by simply rotating the switch to the desired operating mode. Meter shunt resistor R204 has been changed from a 1 watt to a 2 watt rating. The resistance value (5.0 ohms) is unchanged. A positive acting interlock switch has been added, which removes primary voltage from plate transformer T101 when the lid of the cabinet is lifted a slight a- mount. A B+ grounding assembly has been added to the amplifier, which functions to ground the B+ terminal of the power supply, after the lid is lifted sufficiently to open the interlock switch. POWER SUPPLY The voltage rating of capacitor C109 has "been increased from 3^00 to 4000 volts* Circuit changes in the LPA-1 amplifier and LPS-1 power supply are shown on sheet (3). Reference should he made to these changes when trouble-shooting or repairing this equipment. The changes are relatively simple and will he easily understood by comparing the partial schematics to the basic schematic. The following changes should be made in the operating instruction text. Page 3, par. 6d (CW operation) Delete par. 6d in its entirety and substitute the following: 6d. Turn the power supply switch to the OPERATE position (full high voltage) and rotate the BIAS control to the CW position, / Page 5, par. ?e (SSB operation) Delete par. ?e in its entirety and substitute the following: 7e. Turn the power supply switch to the OPERATE position (full high voltage) and rotate the BIAS control to the SSB position. Page 6, par. 8e (SSB with carrier operation) Delete par. 8e in its entirety and substitute the following: 8e. Turn the power supply switch to the OPERATE position (full high voltage) and rotate the BIAS control to the SSB position. P@ge 8, par. lOe (Linear AM operation) Delete par. lOe in its entirety and substitute the following: ^ LF lOe. Turn the power supoly switch to the OPERATE position (full high voltage) and rotate the BIAS control to the SSB position. Make the following changes in the parts list for LPA-1 Linear Power Amplifier (page 16) Change description and part No* of R202 to read v Resistor, adjustable, 5^0 ohms 25 watts. B & ¥ No.4426-7 Change description and part No. of R204 to read r Resistor, shunt, 5 ohms + lfo> 2 watts. B & ¥ part No.4409-36 Add the following symbols descriptions and part nos. / SW202, switch, rotary. 1 pole 2 position. B & ¥ part No.51585 Ordinarily,* the position of the two taps on bias resistor R202 is set at the factory to provide the correct static plate current of 40 ma in the SSB position and 0 ma in the C¥ position, with the equipment operating with 115VAC 60 cycles. If the static plate current departs more than ± 5 wa. from the correct values indicated above, due to line voltage extremes, it will be necessary to readjust the taps on the bias resistor. This may be done as follows. Bias resistor R202 is located on the right side of the chassis and adjacent to the BIAS switch. The position of the sliding tap on R202 nearest the front panel sets the static plate current for the CW position, while the ot^er tap sets the static plate current for the SSB position. Apply AC power not plate voltage to the amplifier. Connect the plus lead of an accurate DC voltmeter to chassis ground. Connect the remaining lead to the CW tap on R202. Position the tap for a reading of minus 19.0 volts. Tighten the screw in the slider and connect the negative lead of the voltmeter to the SSB tap. Position this tap for a reading of minus 5*0 volts. Tighten screw in the slider, remove test leads and close lid of LPA-1 cabinet. With excitation removed from the amplifier, apply full plate voltage. Turn BIAS —1—■ [— ■■ ■■ ■■ “ „ .-fj-. -j T 1 — p- JL- T J X+ ' switch to the CW position and throw meter switch to PLATE. The LPA-1 meter should read 0 MA. Turn Bias switch to SSB. The meter should read 40 ina± 4 ma. This completes the adjustment of Mas resistor R202, HJC Barker & Williamson, Inc. T102 PIG-IRE 7

B&W LPA-1

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