Atlas 210x Installation, Operation And Maintenance Manual Download Page 37

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4-15. PC-400C VFO Circuit Board and Tuning Circuits

PC-400C contains the VFO Oscillator Q401, F.E.T. Buffer 0402, and Output Amplifier 0403. The output of the VFO
Oscillator is coupled through C408 to pin 3 of the external oscillator socket, through the jumper to pin 2, then direct to
terminal 13 of PC-300C. From terminal 13 of PC-300C, the VFO signal is fed to the F.E.T. Oscillator Switch. Voltage
regulation for the VFO circuits is provided by Ql and D2 on the main chassis.

VFO FREQUENCY CHART, MODEL 210x
I.F. at 5520 kHz

SIGNAL RANGE

INTERNAL VFO
RANGE

3500- 4000

7000- 7500

14000- 14500
21000-21500

28400 - 29400

9020- 9520
12520- 13020
8480- 8980
15480- 15980
22880 - 23880

VFO FREQUENCY CHART, MODEL 215x
I.F. at 5520 kHz

SIGNAL RANGE

INTERNAL VFO
RANGE

1800- 2100

3500- 4000

7000- 7500

14000- 14500
21000-21500

7320- 7620

9020- 9520
12520- 13020
8480- 8980
15480- 15980

PC-400C CIRCUIT COMPONENTS

C401, 402, 406, R401, 412 ......

..... 27 10% 1/4 Watt

407, 408 .......... .01 MF l00v Disc R402, 403 ......

.... 10K 10% 1/4 Watt

C403 ................ 300pF 5% SM R404, 409 ......

.... .470 10% 1/4 Watt

C404 ................ 430pF 5% SM R405 .........

.... .680 10% 1/4 Watt

C405 ............... l00pF 10% Disc R406 .........

.... 15K 10% 1/4 Watt

C409 ............. .001 MF 20% Disc R407 .........

.... 4.7K 10% 1/4 Watt

C410 ................ 15pF 5% Disc R408 .........

.... .820 10% 1/4 Watt

L402.................. 1uh RFC R410 .........

.... 2.7K 10% 1/4 Watt

L403.................. 33 uh RFC R411.........

..... 10 10% 1/4 Watt

Q401 .............. 2N706 Osc. Stage R413 .........

..... 100 10% 1/4 Watt

Q402 .............. MPS6514 Buffer

Q403 . .......... 2N3866 Output Amp.

MODEL 21 Ox TUNING SECTION

MODEL215x

TUNING SECTION

C411, 416, 419, 422, 423 . . 3-12pF Trimmer

C428, 433,436,440

, 441 . . 3-12pF Trimmer

C412,413,414 ......... l0pF 10% Disc

C429.........

....... 15pF 5% Disc

C415,420,421,447 ...... 4.7pF 10% Disc

C430, 438, 439 ...

....... 22pF 5% Disc

C417 ................ 22pF 5% Disc

C431,434,435 . . .

...... 4.7pF 10% Disc

C418.424 ............. 20pF 5% Disc

C432,437,442,443

...... 10pF 10% Disc

C425 ................ 27pF 5% Disc

C444.........

....... 0.8pF Dial Set

C426 ................ 0.8pF Dial Set

C445A ........

..... 4pF Main Tuning

C427A ............. 4pF Main Tuning

C445B ........

..... 8pF Main Tuning

C427B ............. 8pF Main Tuning

C446.........

....... 27pF 5% Disc

PC400C VOLTAGE CHART

TERM. STRIP
NUMBER

REC.

TRANS.

0401

Base

Collector

Emitter

+4.5

+3.5

+4.5

+3.5

TERM. STRIP
NUMBER

REC.

TRANS.

Q402

Base

Emitter

Collector

+5.2

+9.2

+5.2

+9.2

TERM. STRIP
NUMBER

REC.

TRANS.

Q403

Base
Collector
Emitter

+4.3

+3.6

+4.3

+3.6

Summary of Contents for 210x

Page 1: ......

Page 2: ...lance 17 3 12 S Meter Zero 17 3 13 Crystal Calibrator 17 3 14 Proper tuning od Single Sideband Signals 17 3 15 Voice Transmission 17 3 16 Modulation Level 18 3 17 ALC 18 3 18 CW Transmission 18 3 19 Heat Sink 18 Section 4 CIRCUIT THEORY 20 4 1 Introduction 20 4 2 Receiver Input Circuit 20 4 3 Sensitivity 20 4 4 Selectivity 20 4 5 Oscillator Switching 20 4 6 Transmitter Broadband Circuitry 24 4 7 R...

Page 3: ...C Boards 21 4 2 ATLAS 210x 215x Block Diagram 22 4 3 Crystal Ladder Filter Selectivity Characteristics 23 4 4 PC 100C Schematic Diagram 27 4 5 PC 200C Schematic Diagram 29 4 6 PC 300C Schematic Diagram 31 4 7 PC 500D 520A Schematic Diagram 33 4 8A Model 210x PC 400C Schematic Diagram 35 4 8B Model 215x PC 400C Schematic tuning section only 35 4 9 PC 600 Schematic Diagram 37 4 10A Model 210x PC 800...

Page 4: ...t advanced state of the art circuit designs to the amateur radio market Les Earnshaw founder and Director of R D at Southcom International is considered to be one of the foremost solid state engineers in the world effectively proved by the rapid growth of Southcom International in the military and commercial radio markets of the United States as well as many other countries The high performance an...

Page 5: ...s 1800 3000 kHz Model 215x only 3000 5200kHz 5800 10000 kHz 13800 14900kHz 20600 21600 kHz Note The Model l0x will not operate on the 28 0 MHz band CIRCUIT DESIGN All solid state 4 IC s 18 transistors 31 diodes Single conversion 5520 kHz I F MODULAR CONSTRUCTION Includes plug in circuit boards for ease of maintenance PLUG IN DESIGN Transceiver plugs into the Deluxe Mobile Mounting Bracket or into ...

Page 6: ... disconnected automatically and front facing speaker on console becomes operative METER Reads S units from 1 to 9 plus lOtoSOdb CALIBRATOR Provides 100 kHz check points for accurate dial setting TRANSMITTER SPECIFICATIONS CIRCUIT DESIGN Broadband design eliminates transmitter tuning Single conversion from I F to output frequency produces minimum spurious and mixing products 2 section low pass filt...

Page 7: ...in oval 1 1 oz magnet 3 2 ohm voice coil FINISH Textured Vinyl bonded to aluminum durable and scratch resistant PLUG IN DESIGN Transceiver plugs directly into power supply console automatically makes connections for antenna and front facing speaker Mic jack and headphone jack are brought out to front panel ACCESSORIES Space under transceiver permits addition of VOX unit Space in rear permits addit...

Page 8: ...s with operating time determined by receive transmit ratio and modulation level The battery has an Amphere Hour rating of 7 5 A H It comes in a simulated leather case with shoulder strap and includes an AC charger Your Atlas dealer may handle Globe products Also it is anticipated that Atlas Radio may have the GC1400 pack available for Atlas dealers Otherwise you may contact Globe directly for refe...

Page 9: ...nator with the engine running at about twice idling speed Voltage at the battery terminals should measure 13 volts minimum 14 5 volts maximum Consult your auto electric service shop if correction is required 2 5 DELUXE MOUNTING KIT DMK The Deluxe Mobile Mounting Kit is a plug in unit designed for easy removal of the Atlas transceivers All D C power connections are made to the DMK and all necessary...

Page 10: ...igh SWR will not damage the 1 1 98 watts Atlas transceiver You may feel 1 2 95 watts free to operate regardless of the 1 3 90 watts SWR Only power input and 1 5 80 watts output will suffer Reflected 2 0 50 watts voltage will not cause damage 3 0 20 watts 2 12 AMMETER READINGS The ammeter on the Atlas transceiver provides an excellent indicator of impedance match In CW transmit mode the Mic Gain co...

Page 11: ...al 216 VOICE OPERATED TRANSMISSION VOX Most press to talk microphones arc short circuited when the button is not pressed if the VOX accessory is installed in the AC console this feature must be disabled Refer to instructions that come with the Mic Open the case and locate the switch contacts that short the Mic circuit when the button is not pressed either disconnect the leads or bend the contact s...

Page 12: ...ut circuit are negative going If this is the case with your linear and you wish to utilize ALC control from the linear it will be necessary that you modify the linear ALC circuit This will usually consist of reversing one or two diodes in order to generate a positive voltage control instead of negative In view of this requirement you may choose to use the ALC system of the Atlas transceiver alone ...

Page 13: ...reaker supplied with the kit should be installed in series with the positive lead It is best to mount it close to the battery end of the cable at some convenient place on the side of a metal panel or bracket Sheet metal screws are supplied for this purpose It is not important that the metal case of the circuit breaker be grounded since there are no connections made to the case Cut the positive red...

Page 14: ...crews that came in the transceiver thus allowing for the 1 8 inch thickness of the bracket The No 6 screws will make the brackets more secure than the original No 4 s would The No 14 screws are for securing the brackets to the under side of the dash or to the transmission hump No 10 screws are also furnished in case the No 14 screws are too large Figure 2 4 Mobile Bracket Kit Installation 2 25 INS...

Page 15: ...metal panel or bracket Short metal screws are supplied for this purpose It is not important that the metal case of the circuit breaker be grounded since there are no connections made to the case Cut the positive red or white power lead install No 10 terminal lugs and secure firmly to the circuit breaker with washers and nuts Solder the terminal lugs 2 27 OTHER D C INSTALLATIONS In the event that y...

Page 16: ...required is actually borrowed from the lower part of the loading coil The capacity value must be determined experimentally and will vary from band to band as well as from installation to installation On 75 meters the capacity will generally need to be in the 1000 to 1500 picofarad range On 40 meters 300 to 400 picofarads and on 20 meters about 200 picofarads A variable capacitor can be useful to d...

Page 17: ...be essential since even at resonance it is unlikely that the feed point will be near 52 ohms In any case it is always best to optimize the antenna system for the frequency where you do most of your operating 2 34 ANTENNA TUNER OR MATCH BOX An antenna tuner can be a very useful device to compensate for antenna mismatch This may be especially true if you happen to have a favorite antenna that has be...

Page 18: ...talk switch is used or if you wish to hold in transmit mode without having to hold the push to talk button down The CW position is also transmit mode except that the Mic Gain control now becomes a Carrier Insertion control and carrier frequency has been shifted about 800 Hertz See CW Transmission 3 6 A F GAIN The A F GAIN control is used to control audio volume in receive mode 3 7 R F GAIN The pur...

Page 19: ...Figure 3 1 Front Panel of ATLAS 210x Figure 3 2 Rear Panel of ATLAS 210x 215x 16 ...

Page 20: ...TAL CALIBRATOR The 100 kHz calibrator should be checked every 6 months or so against a frequency standard such as WWV Aging will cause it to gradually change frequency especially during the first few months The calibrator is mounted on the back side of the aluminum partition under the shield behind the dial drum A capacitor trimmer in the upper left hand comer is for frequency adjustment A test le...

Page 21: ...ng is accomplished by bias cutoff of the I F Amplifier The keying circuit operates at less than 10 volts positive to ground and draws less than 5 milliamps so any of the electronic keyers will work ok In CW transmit mode the carrier frequency is automatically shifted approximately 800 Hertz This makes it possible for one transceiver to QSO another transceiver on CW without having to constantly tun...

Page 22: ...O PUT YOUR FINGERS ON THE FINS CLOSEST TO THE TRANSISTORS IF YOU CAN HOLD ON WITHOUT A LOT OF DISCOMFORT YOU RE OK OVERHEATING MAY BE CAUSED BY A MODULATING TOO HEAVILY B MAKING LENGTHY TRANSMISSIONS WITH SHORT RECEIVING PERIODS OR C RESTRICTION OF AIR CIRCULATION AROUND THE HEAT SINK IF THE AIR TEMPERATURE IS HIGH SUCH AS ON A HOT DA Y OR IN A HOT PARKED CAR COOLING CAPACITY WILL BE REDUCED A GOO...

Page 23: ...Atlas is at least as sensitive as the best of the tube or solid state receivers having R F Amplifiers This is due largely to the very low noise figure of the double balanced diode ring mixer followed by a low noise I F Amplifier Sensitivity is rated at 0 3 microvolts for a signal plus noise to noise ratio of 10 dB Typical measurements will read 0 15 to 0 2 microvolts 4 4 SELECTIVITY Following the ...

Page 24: ...21 ...

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Page 26: ...Figure 4 3 Crystal Ladder Filter Selectivity Characteristics 23 ...

Page 27: ...d two section low pass filter This filter is connected between the Power Amplifier output and antenna terminal The low pass filters and Power Amplifier are both designed for a 50 ohm load It is important that the load be quite close to 50 ohms non reactive in order to operate at full rated power 4 7 RECEIVER BROADBAND CIRCUITRY The receiver input filters are band switched and provide full band cov...

Page 28: ... 6 900 13 800 20 800 27 800 2 150 4 150 7 700 14 700 21 700 30 000 1 8 MHz band model 215x only 28 4 MHz band model 210x only b Extended frequency limits by adjustment of VFO trimmers VFO trimmers are reached by removing the transceiver top cover Adjustment of a trimmer for lower or higher frequency will move the entire band down or up and will came the dial Male to read less accurately Special fr...

Page 29: ...e I F frequency of 5520 kHz and is tuned by the tuned circuit consisting of C104 through C107 and L103 Q101 is the Transmit I F Amplifier and its output is coupled to the Crystal Ladder Filter in the same manner as in the receive mode Diode D105 is used to short the receiver input circuit in transmit mode thus preventing stray transmitter energy from entering the mixer circuit Diodes D106 107 and ...

Page 30: ... 6 Gnd Gnd 7 0 0 33 2 8 Gnd Gnd 9 N C N C TERM STRIP NUMBER REC TRANS 10 13 13 11 13 13 12 Gnd Gnd 13 11 8 10 2 14 7 3 4 8 5 4 15 3 0 3 0 16 3 0 3 0 17 13 12 6 18 13 12 6 TERM STRIP NUMBER REC TRAMS 19 3 12 6 20 13 21 3 13 22 12 6 Q101 I F Amp Base 4 0 161 5 1 Collector 12 216 9 4 Emitter 3 4 6 4 4 27 ...

Page 31: ...Second Mixer in the same manner as in the receive mode The VFO injection frequency is through terminal 7 of PC 200C through C208 to the center tap of the Trifilar Toroid Transformer L203 The heterodyning action of the Second Mixer produces the RF transmit frequency which is coupled through the primary winding of L203 to terminal 9 of PC 200C Q202 which is an integrated Circuit acts as a 3 stage Mi...

Page 32: ...nd Gnd 13 0 33 21 14 6 15 Gnd Gnd TERM STRIP NUMBER REC TRANS 16 9 0 06 12 17 0 0 18 Gnd Gnd 19 3 5 3 5 20 2 6 2 6 21 10 10 22 2 6 2 6 Q201 I C I F Amp Term 1 2 8 10 4 10 1 3 7 Gnd Gnd 4 0 39 0 37 5 0 45 0 43 6 0 38 0 36 TERM STRIP NUMBER REC TRANS Q202 I C Mic Amp Term 1 5 5 3 2 4 14 4 2 3 3 5 6 2 1 7 e 1 5 8 0 5 3 9 3 4 3 4 10 2 7 2 7 11 9 8 9 8 12 e 0 95 14 0 25 ...

Page 33: ...rom the SWR bridge will reduce I F gain resulting in reduced transmitter drive SWR figure of 6 or more will practically cutoff the transmitter drive through this circuit Q303 304 305 and 306 are the F E T Oscillator switches which connect the VFO and Carrier Oscillator BFO to the two mixer stages in proper relationship for receive and transmit functions The switching is controlled by the T line on...

Page 34: ...1 Gnd Gnd 22 0 0 TERM STRIP NUMBER REC TRANS Q301 I C A F Amp Term 1 5 6 7 2 4 2 2 3 1 5 6 4 2 7 3 5 8 9 8 12 1 9 13 1 2 14 12 Q302 I C A F Amp Term 1 7 0 6 2 3 4 5 7 9 10 11 All Grounded 12 13 6 0 8 5 2 1 8 14 13 13 TERM STRIP NUMBER REC TRAMS Q303 Gate 0 7 9 Source 8 8 8 Drain 8 8 8 Q304 Gale 9 8 Source 8 8 8 Drain 8 8 8 Q305 Gate 94 Source 8 8 8 Drain 8 8 8 Q306 Gate 0 7 9 Source 8 8 8 Drain 8 ...

Page 35: ...ors Reflected voltage which is generated by a mismatch in the antenna system is rectified by D1102 and D1103 on PC 1100A in a doubler circuit filtered and then connected to Q507 the SWR protect circuit There it is used to reduce the gain of the first pre amplifier thus reducing drive to the power output amplifier The trimpot R522 is adjusted so that Standing Wave Ratios greater than 2 to 2 5 will ...

Page 36: ...0 3 5 Collector 0 10 2 Emitter 0 2 8 Q502 Base 0 2 4 Collector 0 12 6 Emitter 0 1 5 TERM STRIP NUMBER REC TRANS Q503 Base 1 3 Collector 15 13 Emitter 1 Q604 Q506 Base 4 7 Collector 16 13 Emitter TERM STRIP NUMBER REC TRANS Q606 Base Collector Emitter 03 1 2 13 7 ...

Page 37: ...MF l00v Disc R402 403 10K 10 1 4 Watt C403 300pF 5 SM R404 409 470 10 1 4 Watt C404 430pF 5 SM R405 680 10 1 4 Watt C405 l00pF 10 Disc R406 15K 10 1 4 Watt C409 001 MF 20 Disc R407 4 7K 10 1 4 Watt C410 15pF 5 Disc R408 820 10 1 4 Watt L402 1uh RFC R410 2 7K 10 1 4 Watt L403 33 uh RFC R411 10 10 1 4 Watt Q401 2N706 Osc Stage R413 100 10 1 4 Watt Q402 MPS6514 Buffer Q403 2N3866 Output Amp MODEL 21 ...

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Page 39: ...C the carrier frequency is fed direct to the F E T Oscillator Switch PC 600 CIRCUIT COMPONENTS Carrier Oscillator Buffer Amplifier C601 22 pF 10 Disc R601 4 7K 10 1 4 Watt C602 603 5 30 pF Trimmer R602 604 15K 10 4 Watt C604 10pF 10 Disc R603 613 1K 10 4 Watt C605 606 607 611 612 01 MF 100V Disc R605 220 10 Watt C608 200 pF 5 Silver Mica R606 22K 10 4 Watt C609 100pF5 Silver Mica R607 10K 10 4 Wat...

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Page 41: ...pF 10 Disc L805 806 65 uH Toroid C807 l0pF 10 Disc L807 808 1 4 uH Tuned Q808 809 810 811 91 pF5 Disc L809 810 811 812 65 uH Tuned C812 813 47 pF 10 Disc L1201 1202 6 uH Tuned 5520 Khz C814 180 pF5 SM L1203 6uHTuned 11 8Mhz Q1201 1202 0022 MF 10 Mylar L1204 11 8Mhz C1203 1210 470pF5 SM L1210 17 8 MHz C1211 200 pF5 SM MODEL 215x PC 810C 1200 CIRCUIT COMPONENTS Receiver Input Tuning C815 360 pF5 SM ...

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Page 44: ...r another known standard C821 should then be adjusted to zero beat with the standard signal Output from PC 820 is coupled through C824 to the input terminal of PC 800C and its harmonics will be received at the 100 kHz increments on each band PC 820 VOLTAGE CHART Function Switch in CAL position Q821 Q822 Base 2 5 Base 3 4 Collector 4 Collector 6 Emitter 0 Emitter 0 PC 820 CIRCUIT COMPONENTS C821 5 ...

Page 45: ...roid C905 906 820 pF 10 Disc L905 906 62 uH Toroid C907 2 2 pF 10 Disc L907 908 909 910 2 uH Toroid C908 911 39pF5 Disc L911 912 1 uHToroid L913 914 0 6uHTuned C909 910 913 914 916 917 4 40 pF Trimmer C912 915 1 pF 25 Disc R901 902 47 10 1 4Watt C918 919 0022 MF 10 Mylar R903 904 6 8K 10 1 4 Watt MODEL 215x PC 900C CIRCUIT COMPONENTS Transmitter Input Tuning C920 923 1500 pF 10 Mylar L915 916 917 ...

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Page 47: ...off C1001 820pF5 SM FC I 1 C1016 2200pF 5 SM FC 1 C1002 1300 5200 Khz C1017 2200 25 00 Khz C1003 820 C1018 2200 L1001 1002 1 8 uH Toroidal L1011 1012 2 9 uH Toroidal C1004 430pF5 SM FC 2 2 C1019 820pF 5 SM FC 2 C1005 680 10 000 Khz C1020 1300 5200 Khz C1006 430 C1021 820 L1003 1004 95 uH Toroidal L1013 1014 1 8 uH Toroidal C1007 180pF 5 SM FC 3 3 C1022 430pF 5 SM FC3 C1008 330 20 000 Khz C1023 680...

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Page 49: ... used to control I F gain on PC 200C The capacity trimmer C1107 is the bridge null adjustment It is adjusted by measuring reflected voltage output at the terminal which goes to PC 500D with a VTVM on its lowest scale Use a dummy load which is known to be 50 ohms nonreactive set the bandswitch to the highest band and insert a small amount of carrier in CW transmit mode just enough to get a voltage ...

Page 50: ...rcuit The threshold control R120 is located on the front panel and controls the gain of Q103 A second threshold control R128 is a trimpot located on the PC 120B circuit board and is factory adjusted so that noise pulses will switch Q105 completely but not excessively OPERATION a When the threshold control is in full counterclockwise position the noise blanker is OFF b Advancing the control clockwi...

Page 51: ......

Page 52: ...d 3 and pins 5 and 6 Once the wires have been removed the transceiver VFO will not function unless the lOx is plugged in and switched to its VFO position or the dummy jumper which is furnished with the lOx is inserted in the EXT OSC socket CRYSTAL REQUIREMENTS FOR THE 10X The crystal sockets in the lOx are designed for type HC6U crystals with standard 050 inch diameter pins Crystals must be ordere...

Page 53: ...elector in OPP position Crystal Frequency equals Signal Frequency minus 5523 3 kHz Example 14 370 5523 3 8846 7 kHz For operation on upper sideband USB Bands 160 75 40 meters Sideband Selector in OPP position Crystal Frequency equals Signal Frequency plus 5523 3 kHz Example 4020 5523 3 9543 3 Bands 20 and 15 meters Sideband Selector in NORM position Crystal Frequency equals Signal Frequency minus ...

Page 54: ...equires a close match to a 50 to 53 5 ohm non reactive load Practically none of the mobile antennaes currently on the market will match the coaxial feedline closely enough to provide a proper load for the broadbanded amplifier With the Atlas MT 1 transformer a tap selection will be found which will provide SWR readings of 1 4 or less when using the common type mobile antennaes such as those manufa...

Page 55: ... you expect to return to Another new feature now provides for correct reading on opposite sideband as well as the normally used sideband All L E D Dot Matrix 6 digit display reads within 100 Hz just 1 10 kHz of your actual operating frequency Bright display clearly visible under high ambient light Reads on both Receive and Transmit Measures 1 3 8 high x 5 3 8 wide x 5 7 8 deep ATTENTION SWAN OWNER...

Page 56: ...ge Antenna Relay Printed Circuit Board J1 3 Conductor Closed Circuit Enclosed A F Output Jack J2 3 Conductor Open Circuit Enclosed Mic Jack J3 Banana Jack j4 9 Pin Mica Tube Socket j5 Coaxial Receptacle J6 9 Pin Mica Tube Socket J7 2 Conductor Closed Circuit Enclosed CW Key Jack P1 P2 Banana Plugs M1 S Units P A Amps 500 uA Meter FL1 5520 3 5523 0 8 Pole Crystal Ladder Filter S1 S2 SPDT Slide Swit...

Page 57: ...ATLAS RADIO INC 417 Via Del Monte Oceanside California 92054 714 433 1983 ...

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