Hallicrafters SR-400 CYCLONE II, Manual

Page 1: ...PLIED IF YOU ARE RIGHT HANDED YOUR LEFT HAND IS IN YOUR HIP POCKET IF YOU ARE LEFT HANDED YOUR RIGHT HAND IS IN YOUR HIP POCKET YOU PROCEED AT YOUR OWN RISK This document is the intellectual property...

Page 2: ...COMMUNICATIONS TRANSCEIVER MODEL SR 400 X If this procedure is followed in the order presented you will minimize the frustration of restarts and backups and chasing red herrings It assumes a working k...

Page 3: ...T CONDITIONS 10 2 3 PROCEDURE OVERVIEW PRESET CONDITIONS 10 2 4 RECEIVER FAULT ISOLATION CHART 11 2 5 AGC TEST 12 2 5 1 AGC FIGURE OF MERIT 12 2 5 2 AGC THRESHOLD ADJUSTMENT 12 2 6 S METER ZERO 12 2 7...

Page 4: ...CH NOTES 19 5 1 BASIC TUNE UP 19 5 1 1 THE PROBLEM 19 5 1 2 WHY IS THIS IMPORTANT 19 5 1 3 A SIMPLE SOLUTION 19 5 1 4 SUMMATION 19 5 1 5 MANUAL SECTION 5 4 MARK UP 20 5 2 PA NEUTRALIZATION 22 5 3 OPTI...

Page 5: ...e mechanical problem first If you are going to upgrade to a higher production run complete those upgrades before you start the electrical tests 1 2 RECAPPING There are only six capacitors that are con...

Page 6: ...AL VOLTAGES ARE OPEN AND EXPOSED ONCE THE COVERS OR CASE IS REMOVED OBSERVE THE FREE HAND RULE THAT IS ANY TIME THE POWER IS APPLIED IF YOU ARE RIGHT HANDED YOUR LEFT HAND IS IN YOUR HIP POCKET IF YOU...

Page 7: ...e Switch back and forth from USB to LSB to insure both oscillators start without any hesitation In USB mode adjust C139 for exactly 1652 800 KHz Switch to LSB mode and adjust C136 for exactly 1650 000...

Page 8: ...max you should see the same swing in frequency as when you rotated the CAL control earlier 1 5 4 2 VFO CORRECTOR The VFO correction ckt adjusts for the frequency off set between USB and LSB NOTE CW op...

Page 9: ...ff tracking of C122 and L21 is required The original manual spec at this point is 2 KHZ But it is normally not difficult to get it less than 500 Hz So why not try Adjust the tuning dial to the black 5...

Page 10: ...is detected it must be cleared before you can go the next step The signal levels were derived from years of testing The levels are not absolute in that an individual receiver may vary as much as 10 A...

Page 11: ...100 uv wt Problem is most likely V4A or associated circuitry See section 4 8 for details 8 V3A Pin 2 6 250 MHz 15 uv wt Problem is most likely V3 A or B or associated circuitry See section 4 9 for de...

Page 12: ...fails either test there is a fault in the agc amp NOTE The procedure in the manual 8 4 D should not be used The manual procedure sets the AGC threshold at the level of ambient noise which is always ch...

Page 13: ...HAND IS IN YOUR HIP POCKET MAJOR KEY POINT the transmitter testing process assumes that the receiver has been tested and is operating to specs 3 1 TEST EQUIPMENT REQUIRED 500 watt wattmeter dummy load...

Page 14: ...next series of tests monitor the plate current via the meter plugged into the power supply One volt equals 100 mills of plate current Keep adjusting the RF LEVEL to keep the plate current below 200 m...

Page 15: ...g contact with ground As shown above I took an old tube shield removed the internal spring and cut off the base of the shield I then bent a large loop one end of a piece of buss wire just a little lar...

Page 16: ...he audio output tube If the voltage on the cathode of CR11 does not drop in transmit mode check the grid of V15 The grid should go to gnd in transmit mode if it does not check relay K2 If the voltage...

Page 17: ...You should see 1650 KHz on the counter If you do not get the proper level of signal on frequency then the fault is likely in the BFO Carrier oscillator or C138 4 5 V7A RX FAULT ISOLATION Perform the...

Page 18: ...or V3 is bad If V3 is known to be good refer to the voltage and resistance charts in the manual to isolate the fault 4 10 V2 RX MIXER FAULT ISOLATION WARNING DAMAGE TO TEST EQUIPMENT POSSIBLE See note...

Page 19: ...rue resonance the PA tubes are operating at their most efficient point and this adds to the life of the tubes At true resonance spurs and harmonics are at minimum At true resonance components in the p...

Page 20: ...GAIN At zero Full CCW At initial turn on and at shutdown always set these two controls to zero or full CCW This will lessen the possibility of inadvertent emissions that could damage the transceiver...

Page 21: ...ent can be achieved If normal function cannot be achieved this fault must be cleared before proceeding D Set the METER selector at RFO S and check to see that the PLATE and LOAD controls are preset pe...

Page 22: ...the PRESELECTOR load or plate controls throughout the rest of this process Power down and remove the top and bottom covers and the P A cover 1 Disconnect the plate voltage at the bottom of L26 be sur...

Page 23: ...ou did T1 10 Tune the freq dial to 3 950 11 Adjust both slugs in T1 and T2 for peak signal Record or make note of the peak voltage 12 Tune the freq dial slowly back to 3 550 while observing the signal...

Page 24: ...RESTORATION OF THE SR 400 24 WD GOF 6 22 20014 6 DATA SHEETS 6 1 VFO FREQUENCY CORRECTION BLACK DIAL SPEC MHz TEST 1 TEST 2 TEST 3 TEST 4 TEST 5 TEST 6 0 4 850 100 4 750 200 4 650 300 4 550 400 4 450...

Page 25: ...10 opt 2 10 opt 3 Tests performed only if options are installed Overall Sensitivity S N N A 1 0uv signal at the antenna terminal will produce a minimum 20db s n n BAND TEST FREQ SIGNAL LEVEL S N N MEA...

Page 26: ...l level not more than 5mv rms shall produce the minimum specified SSB output power on any band _______ SSB Power output Set mic gain set to 8 Inject a standard 2 tone signal into the mic jack FREQ MIN...