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Summary of Contents for NCX-500

Page 1: ...NATIONAL RADIO COMPANY INC 37 WASHINGTON ST MELROSE MASS 02176 NCX 500 TRANSCEIVER...

Page 2: ...ith power cables to directly connect to the NCX 500 When the AC 500 Supply is used an external speaker is required see paragraph 2 2 for installa tion detail Figure 1 illustrates the power connections...

Page 3: ...ws used to hold the cabinet to the chassis and panel assembly be in place and firmly tightened In mobile use the rubber feet may be removed from the bottom of the NCX 500 See figure 2 ee 2 4 MICROPHON...

Page 4: ...A suitable antenna or dummy load presenting 40 to 60 ohms resis tive load impedance should be con nected to the antenna terminals a proper power cable should be con nected from the transceiver and a m...

Page 5: ...200 ma The NCX 500 is now adjusted for SSB operation 3 1 7 CW OPERATION Insert key plug in the rear panel KEY jack Turn the FUNCTION ewitch to TUNE and adjust transmitter as described in paragraph 3...

Page 6: ...e possi ble to obtain a momentary maximum off resonance plate current in excess of 500 ma when the PA TUNE control is rotated away from the point of minimum indicated cprrent If 1100 volts are being p...

Page 7: ...tions the CARRIER IN SERTION control may be preset and will vary the carrier level from zero to full output as indicated by the meter In the SSB position the CARRIER INSERTION control is again inopera...

Page 8: ...5 volt peak to peak as indicated on the oscil loscope For AM operation it is necessary to adjust the CARRIER INSERTION control cw from zero until the meter indicates a final amplifier current of 125 m...

Page 9: ...e balanced primary winding of the output transformer is coupled to a single ended winding which feeds the RECEIVE PATH AGC VOLTAGE XMIT PATH 888 eoueuen CONTROL PATHS XMIT AND RECEIVE input of the 12B...

Page 10: ...e of the 6LQ6 final amplifier to the partially by passed return of the final grid circuit coils driver plate coils pro vides neutralization When the final ampli fier is properly neturalized maximum ou...

Page 11: ...g the AGC a very effective fast attack slow release action The AGC is fed to the grid of the 6GH8 V 7 B S Meter amplifier AGC voltage is connected to the grid return of the RF stage through the gating...

Page 12: ...e CW e position allowing the key to function through this pole and provide grid 4 5 RELAY OPERATION block keying In the foregoing discussion the exact 5 Grounds the RF Gain control bus nature of the r...

Page 13: ...TION switch in TUNE position Connect the oscilloscope to junc tion of F 1 C 98 and C 99 output of the 5 2 MHz crystal filter Tune the top slugs of Tl and T2 transmitter IF transformer for maximum outp...

Page 14: ...uring testing of the fina amplifier stages to be described later 13 5 6 CRYSTAL OSCILLATOR ALIGNMENT Connect the oscilloscope probe to the grid pin 2 of the 6GH8 fv B premixer tube Turn the BAND switc...

Page 15: ...the PA TUNE control to the plate current dip at 450 ma and observe the power output It should exceed 150 watts Carefully rotate the PA TUNE con trol to either side of the dip and observe whether the p...

Page 16: ...the oscilloscope The MIC GAIN should be advanced until the cathode current meter reads 450 ma Output at the scope should be 120 180 volts The waveform at ai this point should appear as indicated in fi...

Page 17: ...jack The oscilloscope display amplitude should decrease indicating proper external control Press the MOX switch to OFF The set is now ready for push to talk operation 16 If all of the tests are met sa...

Page 18: ...r B 50756 5 2 MHz Li2 40 Meter Mixer B 50758 XL Grystal 5 2003 MHz B 50769 Li3 20 Meter Mixer B 50760 2 x2 Crystal 14 6000 MHz B 52042 3 Lia 15 Meter Mixer B 51514 2 x3 Crystal 25 1000 MHz B 52042 2 L...

Page 19: ...ear C123 RESISTORS C165 Rl 3 2 ohms 2 W 43 B 17436 10 C166 R2 650 ohms 1 2 W 22 _ RC20 C169 BF651G R78 2 2K10Wtl0 B 17436 24 R79 750 ohms 10 W 10 B 17436 16 R86 R89 39K 2 W 210 ay TRIMMERS T2 73 C6 C9...

Page 20: ...TOP VIEW FIGURE 7 g T2 TOP CORE PRI TI TOP CORE SEC BOTTOM VIEW FIGURE 7 19...

Page 21: ...e AM PTT or front panel manual operation on transmit with automatic carrier insertion AM detector on receive CW grid block keying on tranemit automatic carrier insertion and CW Bidetone product detect...

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Page 26: ...MT ORRETDRSDAT UES Sree orate Series Tete Shp wormnes vocruce of S00 ESISTONS Somes to ID weMECOnES UMLESS OTHE we odeed tunsct s toLmta eye seeas J imine comment 7 sasnancecoronent L cms crane NCX 50...

Page 27: ...NATIONAL RADIO COMPANY INC 37 WASHINGTON ST MELROSE MASS 02176 NcCX 500 POWER SUPPLY...

Page 28: ...t of the bias winding of Tl is rectified by diodes D2 and D3 This recti fied output is filtered by capacitor C4 and provides 100 volts at approximately 10 ma for bias purposes to terminal 3 of the pow...

Page 29: ...17 VACOR230VAC OTE PLUG SHOWN FACING CONNECTOR END NCX AC 500 Power Supply Schematic...

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