Heathkit Service Bulletins - HD-10/HD-1410 Keyers (Complete)
Joseph W Lutz
joelutz at JUNO.COM
Mon Aug 18 22:24:25 EDT 1997
May 20, 1971
HD-10 Bulletin No:
Electronic Keyer HD-10-1F
A vender change on this four-pin socket make it unuable. All units in
stock are being corrected - - but a run of HD-10 units has been shipped
with this incorrect socket.
An insert is being prepared advising the customer to solder the
transistors directly to the circuit board---eliminating the need for this
part. Any future production will not use this part.
Please advise any customer purchasing an HD-10 to discard the sockets &
install transistors directly on the circuit board. Also, watch for this
problem when servicing the HD-10.
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MAY 23, 1974
HD-10 Bulletin No:
Electronic Keyer HD-10-1
Service Guide HD-10 Keyer
The following steps are a troubleshooting sequence you can use to isolate
each stage of the keyer and check its operation. It is difficult to
check circuits when the keyer is in operation because voltages change
rapidly. With this troubleshooting sequence, you can stop the keyer
action in each state of operation to cehck voltages and other circuit
conditions. After you pinpoint the area of trouble, check all parts and
connections in the associated circuitry.
1. Measure voltages at the points shown in figure 9 on page 32 of the
manual. This checks the circuits for prober bias voltages while they are
at rest. In this condition, each multivibrator has one transistor cut
off and the other saturated, the clamp transistors are all saturated, and
the switch tansistor and its driver are both cut off. The following
transistors will be saturated while the circuits are at rest: Q1, Q3,
Q5, Q6, Q9 and Q11.
The following conditions exist when a transistor is cut off: No collector
current flows; the collector voltage will be nearly at the supply
voltage; and the base will be biased negatively with respect to the
emittor for NPN transistors [2N2712], or positively for PNP transistors
[2N407 and 2N398A].
The following conditions exist when a transistor is saturated: its
collector voltage will be nearly the same as its emitter voltage; if the
voltage between the emitter and base is measured, the base will be biased
toward the supply voltage, silightly positive for NPN transistors, and
slightly negative for PNP transistors.
2. Remove Q1!. Now the audio tone whould be on, indicating that the
audio circuitry works. Replace Q11.
3. Ground teh hand key terminal. A tone should be heard, showing that
Q1 is working, and the transmitter should key, indicating that Q8 is
working. Remove the ground.
4. Remove Q5. A tone indicates that Q7 is working.
5. Measure the emitter-to-base voltage of Q6. A base reading of about 2
volts negative to the emitter indicates that Q6 is receiving the
dash-completion voltage.
6. Ground the base of Q2. Measure the base-to-emitter voltage of Q3. A
reading that shows the base is about 1 volt negative with respect to the
emitter indicates proper dash-completion voltage from Q5 to Q3. Replace
Q5.
7. Ground the base of Q2. Momentarily ground the base of Q5: This
should cause the tone to go on and stay on until the base of Q4 is
momentarily grounded. This indicates that the flip-flop multivibrator is
working. Remove the ground from the base of Q2.
8. Momentarily ground the base of Q5. A short-duration tone signal
indicates that the completion circuitry is working.
9. Remove Q1. the tone should be heard, indicating that the dot signal
is reaching Q7.
10. Measure the base-to-emitter voltage of Q3. a reading that shows the
base is about 2 volts negative with respect to the emitter indicates that
proper dot-completion voltage is reaching Q3. Replae Q1.
11. Remove Q3. Dots should be heard, indicating that the dot generator
is working.
12. Remove Q6. Dashes should be heard, indicating that the
multivibrators are all working. Replace Q3 and Q6.
13. Measure the base-to-emitter voltge of Q3, with the paddle at the
dots position. This voltage should show that the base is about 4 volts
negative, indicating proper dot keying.
14. Measure the base-to-emitter voltage of Q6, with the paddle at dots.
the base voltage should remain positive with respect to the emitter.
15. Measure the base-to-emitter voltage of Q6, with the paddle at
dashes. The base voltages at both Q6 and Q3 should show that these bases
are about 5 volts negative with respect to their emitters,
16. Note: It may also be helpful to refer to the oscilloscope waveforms
in the circuit description, Similar waveforms would be obtained in your
keyer if an oscilloscope with good low-frequencey response is available.
The oscilloscope must be capable of fast rise-time to see the trigger
pulse shown in figure 14, since this pulse is extremely short. A 10:1
divider probe should be used with the oscilloscope to avoid loading the
trigger pulses with cable capacitance.
-----------------------------------------------------------------------------------------------------------------
January 24, 1975
HD-10 Bulletin No:
Keyer HD-10-2
Improper Grounding
When servicing a keyer that is inoperative, check for proper grounding
at:
1. The on-off switch.
2. The two ground lugs on the chassis rear panel.
3. The phone jack on chassis rear panel.
Be sure all hardware at these points is secure.
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Thats everything on the fiche I hold that covers the HD-10 Keyer.
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APRIL 17, 1975
HD-1410 BULLETIN NO:
Electronic Keyer HD-1410-1
MODIFICATIONS FOR USE WITH TEN-TEC, TRITON AND
RIGS WITH SIMILAR KEYING REQUIREMENTS
IT HAS BEEN FOUND THAT THE TEN-TEC ARGONAUT AND TRITON KEYING CIRCUITS
REQUIRE THAT THE KEY-LINE BE BROUGHT TO WITHIN A FEW TENTHS OF A VOLT OF
GROUND TO OPERATE PROPERLY. EITHER OF THE FOLLOWING MODIFICATIONS TO THE
HD-1410 WILL ALLOW IT TO BE USED WITH THE ABOVE UNITS.
A. IF THE HD-1410 IS TO BE USED EXCLUSIVELY WITH THE TEN-TEC OR RIGS
WITH SIMILAR REQUIREMENTS, R27 AND D5 CAN BE REPLACED WITH JUMPER WIRES.
THIS DISABLES Q7 AND ELIMINATES THE .7 VOLT DROP DUE TO D5.
B. IF THE HD-1410 IS TO BE USED BOTH WITH SUCH RIGS AND CATHODE OR GRID
BLOCK KEYED RIGS, THE MODIFICATION SHOWN ON THE ATTACHED SCHEMATIC MAY BE
MADE. THE JACK LABELLED "EXT. KEY" BECOMES A SECONDARY "KEYER-OUT" JACK
FOR USE ONLY WITH RIGS EMPLOYING A POSITIVE KEY LINE, AND SOLID STATE
KEYING CIRCUIT.
1. REFER TO PAGE 40 OF ASSEMBLY MANUAL AND REMOVE THE WIRE BETWEEN JACK
L, LUG 1 [KEYOUT JACK] AND CIRCUIT BOARD HOLE F.
2. DISCONNECT THE REMAINING WIRE FROM JACK L, LUG 1 AND CONNECT TO
CIRCUIT BOARD HOLE F.
3. MOUNT TERMINAL STRIP AND COMPONENTS AS SHOWN:
[[SHOWS TS 431-62 TO BE MOUNTED UNDER TOP SCREW OF JACK L AND BENT
DOWN SLIGHTLY. CONNECT A 4700 OHM RESISTOR BETWEEN LUGS 1 AND 3 OF TS.
CONNECT BASE OF PN 417-801 TO LUG 1 OF TS; EMITTER TO ONE LUG OF JACK L
AND THE COLLECTOR TO THE OTHER JACK L LUG]].
4. CONNECT WIRE FROM LUG 3 OF TERMINAL STRIP TO JUNCTION OF R23 AND R26
ON CIRCUIT BOARD. SOLDER THIS WIRE TO LEAD OF R26.
KEYER KEYS CONTINUOUSLY OR ERRATICALLY
PROBLEMS WITH RF CAUSING THE KEYER TO KEY CONTINUOUSLY OR ERRATICALLY,
PARTICULARLY WHEN USING LONG WIRE OR RANDOM LENGTH ANTENNA SYSTEMS, CAN
BE ELIMINATED BY CONNECTING A .001 UF DISC CERAMIC ACROSS THE KEYER
OUTPUT JACK.
INTERMITTENT SIDETONE
IN SOME UNITS, IF THE "TONE" CONTROL IS FULLY CLOCKWISE [LOW FREQUENCY
END], THE SIDETONE WILL BE INTERMITTENT. TURNING THE POT SLIGHTLY
COUNTERCLOCKWISE WILL ELIMINATE THE CONDITION.
-------------------------------------------------------------------------------------------------------------------
MAY 20, 1975
HD-1410 BULLETIN NO:
KEYER HD-1410-2
SERVICE GUIDE
THE FOLLOWING IS A STEP BY STEP PROCEDURE FOR SERVICE THE HD-1410 KEYER:
EQUIPMENT NEEDED:
1 VTVM [NOT A VOM OR DVM]
SET CONTROLS ON HD-1410 AS FOLLOWS:
AC SWITCH - ON
SPEED - FULL CCW
VOLUME - 1/4 CW
SET VTVM AS FOLLOWS:
TO READ DC + VOLTAGES
C A U T I O N
WHEN MAKING VOLTAGE CHECKS IN THE UNIT, BE VERY CAREFUL WHERE THE PROBE
IS TOUCHED AS 110VAC VOLTAGE IS PRESENT ALSO.
1. THE FIRST TEST IS TO CHECK THE DC VOLTAGES FOR THE POWER SUPPLY AND
PASS TRANSISTOR Q8. IF ANY DEFICIENCIES ARE FOUND IN THIS AREA, THEY
MUST BE CORRECTED BEFORE PROCEEDING ON.
2. THE MOST IMPORTANT SECTION IN THE KEYER IS THE DOT GENERATOR AND DASH
DIVIDER, THIS WILL BE CHECKED AS FOLLOWS:
WITH THE KEYER SHUT OFF, CONNECT A JUMPER WIRE FROM PIN 8 OF IC1D
TO GROUND. WITH THE KEYER SET UP IN THIS MANNER, BOTH THE DOT GENERATOR
AND DASH DIVIDER CAN BE CHECKED AT THE SAME TIME WITHOUT PUSHING THE
PADDLES. TURN THE KEYER ON. CONNECT THE GROUND LEAD OF THE VTVM TO THE
CHASSIS OF THE KEYER.
A. SET THE VTVM TO A 1.5VDC RANGE AND TOUCH THE PROBE TO PIN 10
OF IC2D. THE METER SHOULD READ ABOUT .16 AND THE NEEDLE SHOULD BE
OSCILLATING SLIGHTLY. IF THESE RESULTS ARE NOT OBTAINED, CHECK Q1, Q2,
C3, D1 AND SPEED CONTROL.
B. SET THE VTVM READ +5VDC RANGE AND TOUCH METER PROBE TO PIN 5
OF IC4A. READING SHOULD BE .16VDC WITH NEEDLE OSCILLATING SLIGHTLY.
CHECK D3 AND R12, IF PROPER RESULTS ARE NOT OBTAINED.
C. TOUCH METER PROBE TO PIN 8 OF IC4A. METER NEEDLE SHOULD
OSCILLATE RAPIDLY BETWEEN 1.5 ADN 2.5VDC. IF PROPER RESULTS ARE NOT
OBTAINED, FIRST CHECK PIN 2 OF IC4A. METER NEEDLE SHOULD OSCILLATE
BETWEEN 3.6 TO 4VDC AT HALF THE RATE OF PIN 8, REPLACE IC-4 IF
NECESSARY.
D. TOUCH METER PROBE TO PIN 13 OF IC4B. METER NEEDLE SHOULD
OSCILLATE BETWEEN .5 AND 3.5VDC AT 1/2 THE RATE OF TEST C ABOVE. IF
PROPER RESULTS ARE NOT OBTAINED, CHECK PINS 14 AND 3 OF IC-4 FOR 5VDC.
REPLACE IC-4, IF NECESSARY.
E. TOUCH THE METER PROBE TO PIN 13 OF IC3C. METER NEEDLE SHOULD
OSCILLATE FROM 1.6 TO 3.4VDC. IF PROPER RESULTS ARE NOT OBTAINED, CHECK
PIN 13 OF IC3C FOR 5VDC. REPLACE IC3C, IF NECESSARY.
3. OUTPUT CIRCUITRY: SINCE THE JUMPER IS ALREADY INSTALLED IN THE BIT
GENERATOR AND DASHES ARE BEING PRODUCED, WE'LL USE THIS SAME APPROACH FOR
CHECKING THE OUTPUT CIRCUITRY.
A. TOUCH THE METER PROBE TO THE [C] OF Q4. METER NEEDLE SHOULD
SWING BETWEEN .2VDC AND 2.8VDC. IF PROPER RESULTS ARE NOT OBTAINED,
CHECK RESISTOR R24. REPLACE Q4.
B. TOUCH THE METER PROBE TO THE [C] OF Q5. METER NEEDLE SHOULD
OSCILLATE BETWEEN .3VDC AND .8VDC. IF PROPER RESULTS ARE NOT OBTAINED,
CHECK R25. REPLACE Q5.
C. TOUCH METER PROBE TO POINT [J] OR KEYER OUTPUT JACK. METER
NEEDLE SHOULD OSCILLATE FROM .3VDC TO .8VDC. IF PROPER RESULTS ARE NOT
OBTAINED, CHECK OR REPLACE D4.
D. REPEAT THE SAME PROCEDURE FOR Q6, Q7 AND D5.
4. TONE OSCILLATOR CIRCUIT. JUMPER WILL STILL BE CONNECTED TO PIN 8 OF
IC1D.
A. TOUCH METER PROBE TO PIN 4 OF IC5D. NEEDLE SHOULD OSCILLATE
BETWEEN .6 AND 1.4VDC. IF PROPER RESULTS ARE NOT OBTAINED, CHECK C5, C6,
TONE CONTROL. REPLACE IC-5.
B. TOUCH METER PROBE TO [C] OF Q3. METER NEEDLE SHOULD
OSCILLATE BETWEEN 4.3 AND 4.7VDC. IF PROPER RESULTS ARE NOT OBTAINED,
CHECK C7, R21. REPLACE Q3.
5. PADDEL CONTROL AND MEMORY LOGIC: SHUT OFF THE KEYER AND UNSOLDER THE
JUMPER WIRE FROM PIN 8 OF IC1D.
A. TURN THE KEYER ON AND WITH THE VTVM CHECK THE LOGIC LEVELS
FOR IC-1, IC-2 AND IC-3 AS SHOWN ON THE SCHEMATIC. WITH BOTH PADDLES
RELEASED THE LOGIC LEVELS WILL BE REVERSED.
B. MEMORY BIT PROBLEMS CAN ONLY BE IN IC-5, R3, R4, C1 AND C2.
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MAY 20, 1975
HD-1410 BULLETIN NO:
KEYER HD-1410-3
KEYER KEYS CONTINUOUSLY OR ERRATICALLY
IN THE NEXT RUN, A .005MFD [5000PF, PN 21-57] WILL BE ADDED ACROSS THE
KEYER OUTPUT JACK.
THIS SUPERSEDES THE INFORMATION IN BULLETIN NO: HD-1410-1
------------------------------------------------------------------------------------------------------------------- MARCH
26, 1976
HD-1410 BULLETIN NO:
KEYER HD-1410-4
NO DOTS OR DASHES
IF THE UNIT HAS NO DOTS OR DASHES OUTPUT, BUT HAS A TONE IN THE "HOLD"
MODE, CHECK THE INSTALLATION OF Q2. THE CUSTOMER APPARENTLY TRIES TO
TWIST THE TRANSISTOR SO THAT THE FLAT OF THE TRANSISTOR WILL ALIGN WITH
THE FLAT SCREENED ON THE BOARD. THIS WILL CAUSE THE BASE & COLLECTOR
LEADS TO SHORT.
THE MANUAL IS BEING CHANGED TO CLARIFY THE INSTALLATION OF THIS
TRNASISTOR.
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JUNE 24, 1976
HD-1410 BULLETIN NO:
KEYER HD-1410-5
RFI
RFI IN THE KEYER COMING THROUGH THE POWER SUPPLY CAN BE ELIMINATED BY
INSTALLING TWO .005UFD/1.6KV CAPACITORS [PN 21-44] ACROSS THE AC LINE TO
GROUND.
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JULY 9, 1976
HD-1410 BULLETIN NO:
KEYER HD-1410-6
WRONG TYPE OF ROUND KNOB
SOME KITS WERE SHIPPED WITH ORUND KNOBS THAT WILL NOT ACCEPT THE KNOB
BUSHING.
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JULY 24, 1978
HD-1410 BULLETIN NO:
KEYER HD-1410-8
NO DASHES; TONE AND DOTS OKAY
CHECK FOR A POSSIBLE FOIL BRIDGE BETWEEN PINS 8 AND 9 OR BETWEEN PIN 8
AND GROUND OF THE DASHER SET CIRCUIT, IC2 [PN 443-1]. THE BRIDGE IS
USUALLY TOO SMALL TO SEE WITHOUT A MAGNIFIER. THE BRIDGE USUALLY CAN BE
REMOVED BY SCRAPING THE AREA AROUND PINS 8 AND 9 WITH A KNIFE OR OTHER
SIMILAR OBJECT.
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