Hallicrafters SR-150, Operation And Maintenance Manual

Page 1: ...By Walter Cates WD0GOF UPDATE 10 30 2013 1 SUPPLEMENT TO OPERATION AND MAINTENANCE MANUAL HALLICRAFTERS SR 150 Photo courtesy of W4AWM Please help me I can still be a great performer...

Page 2: ...can be brought back to life For those with little or no experience with the SR 150 where to start and how to proceed can be a daunting task One section in this document deals with this resurrection pr...

Page 3: ...er test 11 1 9 TRANSMITTER TESTING 12 1 9 1 TRANSMITTER TESTING EQUIPMENT REQUIRED 12 1 9 2 TRANSMITTER TESTING PROCEDURE 12 1 9 3 TX DRIVE FAULT ISOLATION 13 1 9 4 TX BIAS FAULT 14 2 PRODUCTION RUN U...

Page 4: ...10 30 2013 4 3 10 PA NEUTRALIZATION 35 3 11 SR 150 FILTER PASS BAND EMAIL DISCUSSION 36 4 DATA SHEETS 38 4 1 VFO FREQUENCY CORRECTION 39 4 2 RECEIVER PERFORMANCE 40 4 3 TRANSMITTER PERFORMANCE 41 5 P...

Page 5: ...refore the ESR rating of replacements is important They should have an ESR rating of 1 0 ohms or less ESR s of 0 3 ohms and lower are available This is not a place to save money C115 is a dual cap The...

Page 6: ...e other If not you have a fault that must be fixed before you proceed Otherwise the only thing we need to adjust at this time is rough set the bias voltage On the underside of the Final tubes locate t...

Page 7: ...e is no hesitation in the oscillator startup 1 6 2 HETERODYNE OSCILLATOR The Het Osc is comprised of V8 and its associated circuitry This oscillator is the most troublesome of the three There are not...

Page 8: ...d it must be established that the correction ckts are working properly Connect the frequency counter to the tie point of R15 and C83 Set the function switch to LSB and record the VFO frequency any ban...

Page 9: ...is repeatable and simple to follow Throughout this process we will be injecting signals at different points throughout the radio and monitoring the audio output from the receiver In all cases the outp...

Page 10: ...in 7 V2 7 3MHz 10uv 1 wt Check relay side of C27 for at least 10vpp of carrier injection otherwise V2 and associated cktry is suspect NOTE If step 9 is successful perform a pre alignment at this point...

Page 11: ...lt must be cleared before continuing 2 Connect the gnd lead to the tie point of R22 and C39 this is in the cathode of V4 If the audio output from the receiver increases with the grounding of this poin...

Page 12: ...ontinue go to the TX BIAS FAULT section for more information If you are able to set the bias to 0 7 VDC observing the meter and adjust the BIAS ADJ control to see if you can get 1 5 VDC on the meter Q...

Page 13: ...switch the driver grid or plate coils or plate loading ckt Those faults must be cleared before you proceed You are now ready to neutralize the PA and perform the overall alignment A precise neutraliz...

Page 14: ...operation switch and power supply 1 First locate R126 33K Set your meter to the 200v full scale range and connect the negative lead to R126 That is the end that connects to R125 100K Set the controls...

Page 15: ...he RF tube during transmitting 415003 Change capacitor C76 4 7pf to 10pf 500v plastic mica Change resistor R64 47k ohms to 220K ohms The lead that was connected to ground is now connected to pin 3 of...

Page 16: ...terminal 4 of terminal strip near tubes V1 and V7 Junction of R1 1 Meg and C10 005 uf 2 Replace capacitor C10 005 uf with a 02uf disc capacitor Connected between terminals 4 and 5 of terminal strip 3...

Page 17: ...e relays are next I use thin strips of card paper about 3 long and 3 16 wide Place a drop of DeOxit on the paper and slide it back and forth between the contacts Manually energize the relay and clean...

Page 18: ...By Walter Cates WD0GOF UPDATE 10 30 2013 18...

Page 19: ...By Walter Cates WD0GOF UPDATE 10 30 2013 19 BEFORE CLEANING CLEAN CHASSIS...

Page 20: ...By Walter Cates WD0GOF UPDATE 10 30 2013 20 3 1 2 TUBE SOCKET CLEANING KIT...

Page 21: ...By Walter Cates WD0GOF UPDATE 10 30 2013 21 3 1 3 AIR VARIABLE CLEANING...

Page 22: ...ic 2 Most of the Dynamic mics were specified to be operated into a 100k or higher load Assumptions The Hallicrafters specs state The microphone preamp in each rig is hi Z either 48K or 100K They prefe...

Page 23: ...sis ground Make sure you have good connections and clip leads should not be used Power up using the standard power up and allow 30 minutes for warm up Connect a frequency counter to the junction of R1...

Page 24: ...in the electrical center of their rotation But we have a problem with the heterodyne oscillator Each band has its own xtal and there is no way to adjust individual xtals to get the oscillator to run e...

Page 25: ...Adjust the CAL control for a zero beat Switch the RIT ON OFF switch to on From this point on the RIT ON OFF switch remains on The zero beat will have a weak side and a strong side Now ease the RIT CO...

Page 26: ...have not found a suitable replacement for these relays In 2011 2012 I got involved in a project to get the original manufacturer to do a build of a number of these relays We got some I didn t get any...

Page 27: ...is modification should be undertaken only by an experienced technician A moderate level of skill in reading schematics and tracing ckt wiring is required Install the working original relay in the K2 p...

Page 28: ...g this approach Some K1 relays do not have that contact The contacts are stacked So if you have a junk box full of relays and can find a similar relay you can add the needed contact You will need to a...

Page 29: ...By Walter Cates WD0GOF UPDATE 10 30 2013 29 SUBSYSTEM TECHNICAL INFORMATION CONTINUED 3 5 4 K2 WIRING AND PIN OUT...

Page 30: ...By Walter Cates WD0GOF UPDATE 10 30 2013 30 3 5 5 K3 WIRING AND PIN OUT...

Page 31: ...ers The coil heats a little on all the bands with miss match or improper plate dip However on 80 the tightly wound end gets hot and right now On the high frequency bands that end of the coil is the co...

Page 32: ...up at the RX RF amp V1 Note the RF GAIN control also controls the gain of the second RX mixer V4 When the RF GAIN is at max fully cw the wiper is at ground However when I measured the voltage at the t...

Page 33: ...repair it took 0 8uv to get 500mw of audio output now it is 0 4uv The AGC hit linearity at 25uv before now it hits linearity at 3 5uv The AGC figure of merit holds to 65db over 5uv spec is 50db over...

Page 34: ...I also noted at that time a 10uf 50v capacitor had been added from the cathode to gnd When I removed the capacitor the oscillation stopped I have run into oscillation problems on 4 rigs in recent mon...

Page 35: ...STARTING THE PROCESS YOU NEED TO TUNE THE TX AS BEST AS YOU CAN AT 21 3 MHZ AFTER TUNE UP TURN THE POWER OFF AND DO NOT RE ADJUST THE PRESELECTOR OR FINAL TUNE THROUGHOUT THIS PROCESS POWER DOWN AND...

Page 36: ...KHz the low freq for LSB The high end roll off point is the high freq for the USB or 1651 1 So this means the filter needs to be swept from 1648 7 to 1651 1 for a 2 4 KHz pass band So this tells me t...

Page 37: ...COG NPO and put in a matched set of 1N87 s yes I can still find them and get 58db hot that also maintains at least 52db when cold In some cases I have replaced the 470 resistors and improved rejection...

Page 38: ...By Walter Cates WD0GOF UPDATE 10 30 2013 38 4 DATA SHEETS...

Page 39: ...4 1 VFO FREQUENCY CORRECTION BLACK DIAL SPEC MHz TEST 1 TEST 2 TEST 3 TEST 4 TEST 5 TEST 6 0 4 8519 100 4 7519 200 4 6519 300 4 5519 400 4 4519 500 4 3519 By Walter Cates WD0GOF UPDATE 6 5 2013 42...

Page 40: ...a minimum 20db s n n Factory procedure states ref level is set with 1 0uv at the antenna signal source is then disconnected and replaced by a 50 ohm resistive load The resulting reduction in audio ou...

Page 41: ...IS 150 WATTS Flat topping occurred at __ of mic gain rotation FREQ MIN SPEC PEP 4mv 3 8 MHz 75 W min 7 3 MHz 75 W min 14 3 MHz 70 W min 21 3 MHz 60 W min 28 8 MHz 50 W min THE ADVERTISED INPUT POWER...

Page 42: ...isk are for type test purposes only C Using the PS 150 12 power supply the SR 150 must function between 11 5v and 16 0v DC II RECEIVER PERFORMANCE A Unless otherwise specified control settings shall a...

Page 43: ...lt signal on the 3 5 and 7 0 mc bands shall produce 500mw audio output A 1 0 microvolt signal shall produce 500 mw audio output on all other bands Adjust signal generator frequency for maximum recover...

Page 44: ...r birdies Within the amateur bands shall be less than 0 5 microvolt equivalent CW Signal M AGC Figure of Merit Limit 1 Receiver tuned to 14 3 mc for the check 2 Set signal generator for 5 microvolts u...

Page 45: ...Q RIT Control RIT control at on 1 The RIT control shall affect receiver frequency only Clockwise rotation shall increase receiver frequency 2 The RIT control frequency range shall be or 3 kc minimum...

Page 46: ...or as required 6 Preselector adjusted for maximum drive 7 RF level and mic gain as specified 8 FINAL TUNING as required 9 Calibrator switch at off 10 ANTENNA switch position optional B RF Output Imped...

Page 47: ...age is changed from 105v to 125v AC Balanced at 117v line F Microphone Input Sensitivity 1 TEST FREQUENCY 1000 cps 2 SSB operation MIC GAIN control at maximum 3 An audio level more more than 4 mv or l...

Page 48: ...AIN control set at maximum 2 0 dB reference 1000 cps 50 volts RMS RF output 3 Response Limits either sideband 3 dB limit at 400 to 600 cps With 100 cps max difference between usb and lsb 3 dB limit at...

Page 49: ...flat topping indicating AALC operation O Spurious Output 1 The transmitter shall be tuned and operated in SSB mode at 7 mc Two tone input level shall be adjusted for slight flat topping to produce PEP...

Page 50: ...t their range of adjustment C All rotary switches shall have positive detent action D There shall be no perceptible wobble or vertical movement in the tuning dial when viewed through the dial window E...

Page 51: ...f preselector outer shaft 074 002791 02 and preselector inner shaft 074 002756 03 b Shaft outer final tune 074 002756 02 c Handle knob 030 000793 and screw machine 003 007550 Credits and Disclaimer fo...