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Related Manuals for Hallicrafters SR-400 Series
Summary of Contents for Hallicrafters SR-400 Series
- Page 1 WDØGOF Walt Cates V4.0 7/7/24...
- Page 2 NOTES ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________...
- Page 3 REPAIR & RESTORATION HALLICRAFTERS SR-400 SERIES CYCLONE TRANSCEIVERS CAUTION: FATAL 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.
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Page 4: Introduction
Cyclone II and the Cyclone III but, also apply to the Cyclone. The first generation 400 (Cyclone) had many things not quite correct. Mr. Orwin (Hallicrafters engineer) fixed those when he designed the Cyclone II. The best advice I can offer to owners of the original SR-400 is to upgrade it to the Cyclone II level. -
Page 5: Table Of Contents
TABLE OF CONTENTS INTRODUCTION ..............................4 1. SR-400 INITIAL INSPECTION AND TESTING..................... 8 1-1. VISUAL AND MECHANICAL INSPECTION ..................8 1-2. RECAPPING; .............................. 8 1-3. AFTER MARKET MODIFICATIONS ...................... 8 1-4. INITIAL POWER UP ..........................9 1-4-1. TEST EQUIPMENT REQUIRED ....................... 9 1-4-2. - Page 6 3-5-5 MICROPHONE AMPLIFIER SIGNAL TRACE3-5-4 ..............23 3-5-5-1, SSB MIC AMP TEST PROCEDURE ..................23 3-5-5-2 TUNE/CW/SSB BALANCED MIXER STATIC TEST ............. 24 3-5-5-2-1, SR-400 CW/TUNE/SSB BALANCED MIXER DATA ............ 24 3-6, PRESELECTOR TRACKING ........................25 4. SUBSYSTEM TROUBLESHOOTING AND TESTING ................26 4-1 VFO DRIFT ..............................
- Page 7 6-22. METER CIRCUIT ........................... 53 7. TECHNICAL DISCUSSIONS ......................... 54 7.1. CYCLONE FL1 & NOTCH FILTER MODIFICATION ................. 54 7-2. SR400 LOW POWER IN CW AND TUNE ..................... 56 7-3. SR-400 WEAK RX/TX ..........................57 7-4. SR-400 CYCLONE AND CYCLONE II PA UPGRADE TO 6KD6 ............58 7-5.
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Page 8: Sr-400 Initial Inspection And Testing
1. SR-400 INITIAL INSPECTION AND TESTING. SO, YOU JUST GOT AN SR-400 FROM E-BAY OR SOMEONE THAT SAID “IT WORKED FINE THE LAST TIME I TURNED IT ON”. NOW WHERE DO YOU START? THE FOLLOWING PROCESS HAS EVOLVED OVER YEARS OF REFURBISHING THE SR-400. IT SHOULD BE FOLLOWED IN THE ORDER IT IS WRITTEN. -
Page 9: Initial Power Up
1-4. INITIAL POWER UP Note: When bench testing the SR-400 set the antenna switch (S2) to SEPARATE. Connect the load and wattmeter to ANTENNA (J1 or J2). Connect the signal generator to REC ONLY (J3). This will eliminate the possibility of transmitting into the signal generator. -
Page 10: Check And Adjustment Of Oscillators
1-5. CHECK AND ADJUSTMENT OF OSCILLATORS: Before starting any receiver or transmitter troubleshooting or the RF or I.F. alignment it is imperative that the xtal oscillators and the VFO are precisely on frequency. If you will devote the time to these considerations, you will be rewarded with a rig that performs as well as any modern rig. -
Page 11: Vfo
1-5-4. VFO: The VFO is comprised of V13, V4B and associated circuitry, the VFO correction circuitry and the RIT/CAL circuitry. This VFO is an extremely stable design. It does not need to be “redesigned” or modified to maintain stability. If there are stability problems there is a bad part. In the following procedures we will find that bad part. From the manual: Frequency Stability;... -
Page 12: Vfo Alignment
In LSB it should be a negative voltage in the range of -20 to -28 vdc. If the offset switching voltage is correct and the offset is un-settable then R85 is possible but least likely. CR12, C126 and/or C127 are most likely the cause. If the offset voltage is incorrect the most likely cause is the FUNCTION switch S3A. - Page 13 If the actual frequency consistently falls above or below the spec frequency adjustment of trimmer C122 is indicated. Move the dial to the black 500 index mark (be sure you are looking head on at the dial to eliminate parallax error). Adjust C122 for exactly 4.35 MHZ. Rerun and record the 6 data points again.
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Page 14: Receiver Fault Isolation
Connect the scope via 10X probe to V4 pin 3. You should see a minimum of 1.6vpp across the band. More information on the VFO can be found in section 6-12 This completes the oscillator test and adjustment process. Again, let me stress that diligence in getting the oscillators correct will pay max benefits in the end product. -
Page 15: Receiver Fault Isolation Chart
2-4. RECEIVER FAULT ISOLATION CHART Injection point Frequency Signal Audio If good go to next step. If not check suggestions below. injection output level V15 pin 7 1000 Hz 14 vpp ½ wt. Problem most likely V15 or associated circuitry. 1:1 probe See section 4-2 for details. -
Page 16: Agc Test
2-5 AGC TEST The following agc test results are dependent upon overall gain and sensitivity of the receiver. This assumes a fully functional receiver and proper alignment. If you are in the process of restoring to operation you may not get the agc figure of merit in spec. -
Page 17: Transmitter Testing
3. TRANSMITTER TESTING At the start of the receiver testing, you replaced the power supply fuse with a 4-amp normal delay. It is time to re-insert the 5-amp slo-blow fuse. The goal of this section is not to get maximum power out of the radio. The goal is simply to prove that the major transmitter sections are functioning. -
Page 18: Transmitter Fault Isolation Flow Chart
3-2-1 TRANSMITTER FAULT ISOLATION FLOW CHART... -
Page 19: Bias Adjust
3-3. BIAS ADJUST (plate idle current adjustment) With the power off plug your meter into the test jacks on the power supply chassis + to the red jack – to the blue jack. CAUTION the meter leads will be attached to the PA high voltage, fatal shock hazard is present. Ensure the front panel settings are in accordance with paragraph 3-2 then power up. -
Page 20: Initial Transmitter Tests
3-4 INITIAL TRANSMITTER TESTS Reset all controls as stated in section 3-2 3-4-1 TRANSMITTER POWER TEST The following tests are preliminary test to assess the overall transmitter performance. One hundred watts is sufficient at this point. Set the meter that is plugged into the power supply to the 10 vdc full scale range. Set the RF LEVEL to 5. In the next series of tests monitor the plate current via the meter plugged into the power supply. -
Page 21: Transmitter Fault Isolation
3-5, TRANSMITTER FAULT ISOLATION The assumption at this point is that the receiver works. If it does not you need to back up to section 2 and clear the receiver faults. For the TX fault isolation tests preset the equipment as listed in 3-2. STANDARD TEST CONDITIONS. -
Page 22: 3-5-3, No Or Low Power On A Single Band
Connect the 10:1 scope probe to pin 2 of V18. NOTE: as soon as you connect the probe to the tie-point you will detune the ckt. Some adjustment of L11 may be required to peak the signal. Key the transmitter, advance the RF LEVEL control to 7 and peak L11. -
Page 23: Microphone Amplifier Signal Trace3-5-4
V14 cathode follower or the PPT circuits or the MIC DISABLE circuits. Power down and reinsert V11. When normal operation is achieved You are ready for a full alignment. Go to section V111 in the HALLICRAFTERS, OPERATING AND SERVICE INSTRUCTIONS manual. -
Page 24: Tune/Cw/Ssb Balanced Mixer Static Test
3-5-5-3 TUNE/CW/SSB BALANCED MIXER STATIC TEST In the CW and TUNE functions the USB carrier signal is fed straight through the balanced mixer. The function switch via S3A front, pin 8 applies a ground to the wiper of the carrier bal. potentiometer R132. This causes CR19 to be cut off and CR20 to be saturated resulting in feeding the USB carrier signal through T6 directly to the first 1650 IF amp. -
Page 25: Preselector Tracking
3-6, PRESELECTOR TRACKING Grab your schematic and figure 15 (SR-2000) or figure 16 (SR400) in the factory manual and follow along. The preselector control (C7A, C7B and C7C) tunes three sets of band coils. First (C7A) is the RX RF amp grid. The second (C7B) set of band coils tunes the RX RF amp plate and the 2 TX mixer and Driver grid. -
Page 26: Subsystem Troubleshooting And Testing
4. SUBSYSTEM TROUBLESHOOTING AND TESTING 4-1 VFO DRIFT You have performed all the tests in section 1-5-4 and determined that you have a drift problem. If the drift is present in LSB and USB then the prime suspects are C121, C123 and C124. Do not be concerned about which is bad replace all three. -
Page 27: V6 Rx Fault Isolation
4-7. V6 RX FAULT ISOLATION See section 6-7 4-8. V4A RX FAULT ISOLATION NOTE: In the following steps you will inject a signal into the plate circuit with the tube removed. Be sure voltage.Assumption: You have injected 35uv @ 6 – 6.5 MHz into pin your injection probe will handle the B+ 1 of V6 and there was ½... -
Page 28: Tech Notes
5. TECH NOTES 5-1. BASIC TUNE UP The RF power out and PLATE current monitoring leaves a little to be desired in the SR-150 through the SR-500. This short fall was corrected in the SR-2000 with the addition of a dedicated plate current meter in the power supply. -
Page 29: Pa Neutralization
5-2 PA NEUTRALIZATION Proper neutralization will enhance the proper operation, efficiency, and life of your final tubes. Theory and opinions on the effects of interelectrode capacitance are as numerous as the writers of such articles. So, to be very basic, we are attempting to neutralize the effects of the interelectrode capacitance of the PA final tubes. HERE ARE A FEW SITES THAT HAVE DISCUSSIONS ON NEUTRALIZATION. -
Page 30: Optional 6 Meg If Alignment
This is a member only site. It is free to join and I strongly recommend joining if you are a Hallicrafters fan. In the files section of this site is the largest collection of Hallicrafters technical information I have found anywhere. With over 1000 members, any post to the group will result in... -
Page 31: Subsystem Schematics & Charts
6. SUBSYSTEM SCHEMATICS & CHARTS This section contains uncluttered subsystem schematics and static condition voltage charts. Static condition voltages, generally, are measurements taken in no signal conditions to reflect static bias conditions of subsystems. With some systems signal levels, peak to peak, are important to static operation and those values are include. 6-1 TEST EQUIPMENT REQUIRED In addition to test equipment preciously mentioned in this document you will need a RF BLOCKING DC PROBE. -
Page 32: Rx Rf Amp
6-2. RX RF AMP For this test terminate the antenna jack J1 with 50ohm load. Measurements will be taken with RF GAIN at minimum and at maximum. Test unit B+ = 281vdc. PIN # GAIN @ MIN -0.05 17.22 GAIN @ MAX -0.05 1.53... -
Page 33: Rx Tx
6-3. RX TX 1 MIXER These tests are done with all gain and drive controls set to minimum. Test unit B+ = 281vdc. PIN # RX MODE TX MODE -0.02... -
Page 34: 6Meg If Amp & Aalc Amp
6-4. 6MEG IF AMP & AALC AMP These tests are done with all gain and drive controls set to minimum. Test unit B+ = 281vdc. V3A 6MEG IF AMP PIN # DC VOLTAGE 2.92 V3B AALC AMP PIN # DC VOLTAGE 13.5... -
Page 35: Aalc
6-4-1. AALC AALC FUNCTIONS The Amplified Automatic Level Control circuits are a transmitter function. When transmitting an SSB signal, if the linear PA is overdriven flat-topping occurs. When flat-toping occurs, an audio signal is superimposed on the grid bias line. This is an effect of the grids starting to draw current. The goal is to drive the linear amp right to and slightly beyond the point of drawing grid current. -
Page 36: Nd Rx Mixer
6-5. 2 RX MIXER These tests are done with all gain and drive controls set to minimum. Test unit B+ = 281vdc. PIN # RX MODE TX MODE -61.5 PIN # VFO INJECTION 1.6vpp NOTE: In transmit mode V4A is biased off. Carrier signal from T6 is passed to V6 via C16. In CW mode the signal is amplified and passes through FL1 and on to V2B the 1 TX mixer. -
Page 37: Noise Blanker
6-6. NOISE BLANKER These tests are done with all gain and drive controls set to minimum, in RX mode. Test unit B+ = 281. PIN # R24 @ MIN -134 3.17 R24 @ MAX 3.21 0.16 The 6meg IF signal plus the noise is presented to V5A and amplified. C49 and L14 strip off the 6meg IF signal and present the remaining noise signal to CR7. -
Page 38: St 1650 If & Noise Blanker
6-7. 1 1650 IF & NOISE BLANKER This test is conducted with no signal in and the gain controls set to minimum. Voltages will be measured in RX mode and TX TUNE mode. Ensure the drive to the transmitter is set to minimum. Test unit B+ = 281vdc. -
Page 39: Nd 1650 If Amp
6-8. 2 1650 IF AMP These tests are done with all gain and drive controls set to minimum. Test unit B+ = 281 PIN # RX MODE 2.57 TX MODE... -
Page 40: Agc Amp
6-9. AGC AMP These tests are done with all gain and drive controls set to minimum. Measurements will be taken with AGC THRESHOLD set at min and max. Test unit B+ = 281 Pin # R46 @ MIN -129 R45 @ MAX -118 The adjustment of R46 is covered in section 8-4-D of the factory manual. -
Page 41: Product Detector
6-10. PRODUCT DETECTOR & 1 AUDIO AMP These tests are done with all gain and drive controls set to minimum. Test unit B+ = 281vdc CARRIER INJECTION TP D PEAK TO PEAK VOLTAGE 5.7vpp PIN # VOLTAGE 40.3 -0.60 -0.03 2.48... -
Page 42: Audio Output
6-11. AUDIO OUTPUT These tests are done with all gain and drive controls set to minimum. Test unit B+ = 281vdc. PIN # RX MODE 14.9 TX MODE... -
Page 43: Vfo
6-12. VFO These tests are done with all gain and drive controls set to minimum, in RX mode. Use the RF BLOCKING dc probe for these measurements. Test unit B+ = 281. VOLTAGE VOLTAGE -2.98... -
Page 44: Carrier Oscillator
6-13 CARRIER OSCILLATOR These tests are done with all gain and drive controls set to minimum, MOX, LSB. Test unit B+ = 281. PIN # VOLTAGE NOTE: Use an RF blocking probe for these measurements. RF peak to peak measurements made with an oscilloscope. TEST POINT T4 PIN3 T4 PIN4... -
Page 45: Het Oscillator
6-14. HET OSCILLATOR These tests are done with all gain and drive controls set to minimum. Test unit B+ = 281vdc. PIN # VOLTAGE -6.2 NOTE: Use RF blocking probe to take measurements. -
Page 46: Cal Osc
6-15. CAL OSC These tests are done with all gain and drive controls set to minimum. Test unit B+ = 281vdc. NOTE: Use RF blocking probe to take measurements. Pull the CAL control to the on position. PIN # VOLTAGE Push the CAL control to the off position Turn all the gain and drive controls to minimum. -
Page 47: Nd Tx Mixer
6-16. 2 TX MIXER These tests are done with all gain and drive controls set to minimum. Set the preselector to fully clockwise position. Measurements will be taken in RX mode, and in TX mode with the RF LEVEL at minimum and maximum. -
Page 48: Cyclone Ii Driver
6-17. CYCLONE II DRIVER These tests are done with all gain and drive controls set to minimum. Test unit B+ = 281vdc PIN# RX MODE -111 TX MODE... -
Page 49: Cyclone Ii Pa
6-18. CYCLONE II PA These tests are done with all gain and drive controls set to minimum. Test unit B+ = 281. Idle current set to70ma. PLATE CAP RX MODE TX MODE RX MODE TX MODE... -
Page 50: Cyclone Iii Pa
6-19. CYCLONE III PA These tests are done with all gain and drive controls set to minimum. Idle current set to70ma. R400 balance pot set for balance at J11 and J12. Test unit B+ = 276, HI voltage in RX mode 890, House voltage = 125vac. V16 PINS 3,11 2,4,10... -
Page 51: Vox And Relay Amps
6-20. VOX AND RELAY AMPS These tests are done with all gain and drive controls set to minimum, in RX mode. Test unit B+ = 281vdc. V20A V20B DELAY MAX DELAY MIX... -
Page 52: Side Tone Generator
6-21. SIDE TONE GENERATOR These tests are done with all gain and drive controls set to minimum, function CW, operation MOX with a key plugged into KEY jack in the rear. Test unit B+ = 281. PIN # UN-KEYED KEYED Test point 1 will be a sawtooth signal. -
Page 53: Meter Circuit
6-22. METER CIRCUIT These tests are done with all gain and drive controls set to minimum. Meter switch in the S/RFO position. Test unit B+ = 281vdc. PIN # METER ZERO AT MIN 9.32 -0.09 METER ZERO AT MAX ------------- 10.42 -0.09... -
Page 54: Technical Discussions
7. TECHNICAL DISCUSSIONS 7.1. CYCLONE FL1 & NOTCH FILTER MODIFICATION This is the most complicated part of the upgrade. Take time to trace the ckt on the schematics and in the chassis. The parts circled in red will be removed and discarded. Wires marked with red will be removed. - Page 55 Add and connect components as marked in RED.
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Page 56: Sr400 Low Power In Cw And Tune
7-2. SR400 LOW POWER IN CW AND TUNE Tune the rig up on 3.90MHz, LSB mode, MOX, key the mic and slowly repeat the words "three four three four three four". If the power out is substantially higher than it was in the tune function a fault most likely lies somewhere in the 1650 IF system, could be alignment or component drift. -
Page 57: Sr-400 Weak Rx/Tx
7-3. SR-400 WEAK RX/TX If you have a unit that the transmitter power and the receiver sensitivity both hover at or just below speck you may have a problem with the VFO output. Ideally the peak-to-peak voltage at pin 8 of V4B should be 3.6vpp at the very minimum you should have 3.2vpp. -
Page 58: Sr-400 Cyclone And Cyclone Ii Pa Upgrade To 6Kd6
7-4. SR-400 CYCLONE AND CYCLONE II PA UPGRADE TO 6KD6 Changing the PA finals of the Cyclone and the Cyclone II will give an average increase of 25 watts on 80meters and 60 to 75 watts on 15 and 10meters. The 400A uses the 6KD6 with a screen balance network that did not prove to be very beneficial. -
Page 59: Sr-400 Agc Discussions
7-5. SR-400 AGC DISCUSSIONS QUESTION. ---> Thanks again Walt. This radio is getting to be very nice thanks to you. A small problem still exists... the S meter is very generous; most strong signals are full scale and weaker ones are S7 to S9. This is after a one hour warm up with the meter zero and AGC set per the manual. -
Page 60: 12By7A Driver Tube
If the screen current in the 12BY7A exceeds 6ma it will suffer a shortened life. Hallicrafters and other radio manufacturers bought the tubes in bulk to very tight specifications. Today we do not have that option. This condition is exasperated by the higher voltages delivered by power supplies driven by higher primary AC line voltages. -
Page 61: Data Sheets
8. DATA SHEETS 8-1. VFO FREQUENCY CORRECTION BLACK SPEC TEST 1 TEST 2 TEST 3 TEST 4 TEST 5 TEST 6 DIAL 4.850 4.750 4.650 4.550 4.450 4.350... -
Page 62: Performance Data
8.2 PERFORMANCE DATA 8-2-1. RECEIVER PERFORMANCE DATA Overall Sensitivity (gain) The receiver will produce a minimum of 500 mw audio out with 1 uv RF signal at the antenna terminal. Tests performed at center of General Class bands BAND TEST FREQ SIG REQ FOR 500mw *10 opt 1 10 std... -
Page 63: Transmitter Performance
8-2-2. TRANSMITTER PERFORMANCE Tests performed with 50ohm resistive load. Measurements made with BIRD avg power and PEP power meter. Hi voltage ________vdc B+ ________vdc Bias -________vdc Final amplifier bias set to 70 ma SSB mode zero drive. _________ Neutralization performed @ 21.3 MHZ. _______ Carrier balance null _____ db below full power output level (60 db or more). - Page 64 wd0gof.com...
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