Heathkit Service Bulletins - HW-101

Joseph W Lutz joelutz at JUNO.COM
Fri Jul 11 22:00:58 EDT 1997


--------- Begin forwarded message ----------
From: joelutz at juno.com (Joseph W Lutz)
To: joelutz at juno.com
Subject: HW-101[test]
Date: Fri, 11 Jul 1997 16:03:14 UTC
Message-ID: <19970711.160322.2918.3.JOELUTZ at juno.com>



                        FEBRUARY 11, 1971
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-1

                                   VFO DRIFT

The vfo coil has been changed to improve the drift problem experienced in
many units.  The old coil [PN 40-810] should be replaced by the new coil
[PN 40-1976] whenever a unit displays excessive drift.  This has been
made a permanent change in all future production.
----------------------------------------------------------------------------------------------------------------
                        SEPTEMBER 14, 1972
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-2

        REPEATED HETERDODYNE OSCILLATOR TUBE FAILURE
                INADEQUATE USB-LSB FREQUENCY DRIFT

Change:  R-212 from 220 Ohm to 330 Ohm 1/2 watt resistor [PN 1-4].  Lack
of VFO shift range can be corrected by changing the value of the FET
source resistor.

Change:  R-947 from 470 Ohm to 1000 Ohm [PN 1-9].
------------------------------------------------------------------------------------------------------------------
                        FEBRUARY 16, 1973
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-3

                      CARRIER NULL CONTROL FAILURE

Recently an improved mounting method was devised for the [PN 10-147]
controls in kit models SB-102, SB-401 and HW-101.  Current production
utilizes a fiber washer for greater clearance and the case of the control
is grounded by a separate wire.  We are anxious to know if this will
educe the failure rate.  Please make note of any change, good or bad, and
keep us posted.
------------------------------------------------------------------------------------------------------------------
                        OCTOBER 29, 1973
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-4

                          LOW OUTPUT ON 40 METERS

SEE BULLETIN NO:  SB-102-5 DATED OCTOBER 29, 1973
-------------------------------------------------------------------------------------------------------------------
                        MAY 23, 1974
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-5

               ALTERNATE METHOD OF NEUTRALIZING THE FINAL AMPLIFIERS

SEE BULLETIN NO:  HW-100-3 DATED MAY 23, 1974.
--------------------------------------------------------------------------------------------------------------------
                        MAY 23, 1974
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-6

                      SB & HW SERIES AUDIO PREAMPLIFIER & VOX CIRCUIT
                                             TROUBLESHOOTING GUIDE

SEE BULLETIN NO: SB-100-3 DATED MAY 23, 1974
-------------------------------------------------------------------------------------------------------------------
                        MAY 23, 1974
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-7

        SB & HW SERIES INSTABILITY & CORRECTIVE INFORMATION

SEE BULLETIN NO: SB-100-4 DATED MAY 23, 1974
--------------------------------------------------------------------------------------------------------------------
                        DECEMBER 18, 1974
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-8

                           OSCILLATIONS OR LOW DRIVE

SEE BULLETIN NO: SB-100-5 DATED DECEMBER 18, 1974
--------------------------------------------------------------------------------------------------------------------
                        MAY 2, 1975
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-9

        SELF OSCILLATIONS OCCURRING AFTER INSTALLATION OF
                         STEEL COMB BRACKETS

SEE BULLETIN NO: SB-100-6 DATED MAY 2, 1975
--------------------------------------------------------------------------------------------------------------------
                        MARCH 26, 1976
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-10

                        S-METER DRIFT

To bring the meter drift to an acceptable level, install the following:

        CHANGE:  R107 from 100K Ohm 1/2 Watt to 100K 1 Watt
                        [PN 1-28-1]

This makes the voltage divider string more stable with temperature
changes caused by internal heating.

This change will be made in future production runs.
----------------------------------------------------------------------------------------------------------------                                NOVEMBER
15, 1976
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-11

                                                    LOW RECEIVER
SENSITIVITY

SEE BULLETIN NO. HW-100-7 DATED NOVEMBER 15, 1976
-----------------------------------------------------------------------------------------------------------------
******************************************************************************************
NOTE:  FICHE FOR YEAR 1977 WAS NOT RECEIVED - SORRY.
******************************************************************************************
                        JANUARY 20, 1978
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-18

                     RF CHOKE IN FINAL PLATE CIRCUIT OVERHEATS OR
                 DIFFICULT TO NEUTRALIZE ON 10 METER & 15 METER BANDS

6146B tubes in the final amplifier may be causing this problem.  To
correct, replace with 6146A tubes.

A label will be installed on the back panel of the HW-101 recommending
the use of 6146A tubes only.  The 6146B tubes should not be used as a
replacement.
-------------------------------------------------------------------------------------------------------------------
                        FEBRUARY 2, 1978
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-19

                               VFO SHIFT

The trimmers on the VFO tuning capacitor tend to align at their minimum
capacitance.  Therefore, the head of the screw may not be under
sufficient pressure against the spring plates of the trimmers, and
intermittant frequency shift can result.  Changing C-947 from 56 to 47pf
NPO [PN 21-147] will allow the trimmers to tune to a point with tighter
compression.
--------------------------------------------------------------------------------------------------------------
                        FEBRUARY 3, 1978
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-20

                LOW POWER OUTPUT, S-METER DRIFT, ETC

The #44 pilot lamps presently used in the unit unbalance the
series-parallel filament line because of their 250ma current
requirements.

In each unit srvice, change the pilot lamps to type #47 [PN 412-11].

This change will be incorporated in future runs.
--------------------------------------------------------------------------------------------------------------------
                        MARCH 31, 1978
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW0101-21

        DISTORTED AUDIO, NO CARRIER NULL OR ERRATIC
                       POWER OUTPUT IN VOICE MODE

This problem may be caused by V1 oscillating at approximately 65KHZ,
especially if a "GE" brand tube is used at this location.

To correct,

INSTALL:  .005 uf capacitor [PN 21-57] in parallel with the .2 uf
capacitor at C3.

Install only as needed.
------------------------------------------------------------------------------------------------------------------
                        APRIL 14, 1978
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-22

          RELATIVE POWER METER PEGS ON 15 AND 10 METER

Diode CR-901 [PN 56-26] shuld be ounted on terminal strip BR with 1/2"
leads.  This introduces a slight amount of inductance into the circuit,
which cures the problem.

The next manual level will include this instruction.
--------------------------------------------------------------------------------------------------------------------
                        JUNE 5, 1978
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-23

        RELAYS REMAIN ENERGIZED AFTER TRANSMIT CONDITION

After keying the transceiver with PTT for thirty to forty seconds, a
positive voltage in excess of 10 volts appears at the control grid, pin 9
of V12, thus keeping the relays energized.

To correct the problem, replace V12 [PN411-124].  IEC Brand tubes have
been found defective in several cases, but other brands may also cause
this problem.
---------------------------------------------------------------------------------------------------------------
                        JUNE 5, 1978
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-24

                               POOR AGC ACTION

Leakage in the 6HS6 tubes [PN 411-247] at V10 and/or V11 has been found
to cause:

        - poor AGC action
        - Fast S-meter decay
        - poor sensitivity when RF gain control is fully clockwise.

This usually occurs after warmup of at least an hour.  A positive
voltage, usually over 1 volt, will appear at the grid, pin 1, of either
one or both tubes.

Replacement of the tube with the positive voltage corrects the problem.
----------------------------------------------------------------------------------------------------------------
                        JUNE 5, 1978
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-25

                      100 KHZ CALIBRATOR SPURS

Strong signals may occur at other than 100khz points.

Look at the calibrator output [ahead of output diode] with an
oscilloscope.  Use high input gain and a slow sweep speed.  If the upper
portion of the sine-wave signal appears choppy or uneven, the Y201
crystal may be at fault.

After installation of a new crystal [PN 404-43], recheck with
oscilloscope.
--------------------------------------------------------------------------------------------------------------
                        AUGUST 3, 1978
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-26

                           RECEIVER RECOVERY SLOW

THIS BULLETIN OBSOLETE.  REFER TO BULLETIN NO: HW-101-36 DTD OCTOBER 10,
1978.
---------------------------------------------------------------------------------------------------------------
                        JULY 24, 1978
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-27

                             ERRATIC VFO TUNING

Erratic tuning can be caused by an intermittant electrical contact in the
vernier drive of the tuning capacitor.  This causes a change in the
ground path from the capacitor frame.  This affects the capacitance and
subsequently, the tuning.

To prevent this, solder a heavy gauge wire or braid from the stop stud to
a solder lug under the closest mounting screw.  This provides a suitable
short ground path from the capacitor frame to ground.
-------------------------------------------------------------------------------------------------------------------
                        JULY 24,1978
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-28

        CARRIER NULLS WITH IC14 TRIMMER PLATES COMPLETELY
                                      MESHED


SEE BULLETIN NO: HW-100-14 DATED JULY 24, 1978.
-------------------------------------------------------------------------------------------------------------------
                        JULY 24, 1978
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-29

                       POOR PRESELECTOR TRACKING

SEE BULLETIN NO: HW-100-13 DATED JULY 24, 1978.
-------------------------------------------------------------------------------------------------------------------
                        AUGUST 1, 1978
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-30

        LOADING CAPACITOR TURNS AS PLATE CAPACITOR
                                                IS ROTATED

SEE BULLETIN NO: HW-100-16 DATED AUGUST 3, 1978.
--------------------------------------------------------------------------------------------------------------------
                        AUGUST 3, 1978
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-31

                         RELAYS CHATTER IN VOX MODE

SEE BULLETIN NO: HW-100-15 DATED AUGUST 3, 1978.
--------------------------------------------------------------------------------------------------------------------
                        AUGUST 3, 1978
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-32

                "CHIRPING" AND SLOW RECEIVER RECOVERY

If "chirping" of the audio in the receive mode and slow recovery of the
receiver after long periods of transmitting are encountered, remove the
cover of RL2 and check for carbon buildup at the base, just below the
contact.  Clean dirt or carbon tracks, or replace if necessary.

A dirt or carbon buildup will cause the +300 volts to be applied to
adjacent contacts such as the bias or AGC lines, adversely affecting
receiver cutoff by upsetting the operation of 1] V12, receiver mixer; 2]
V10, RF amplifier; and 3]V11, first receiver mixer.
-------------------------------------------------------------------------------------------------------------------                             AUGUST
21, 1978
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-33

                    ALC METER READS BELOW ZERO

SEE BULLETIN NO: HW-100-18 DATED AUGUST 21, 1978.
--------------------------------------------------------------------------------------------------------------------
                        AUGUST 22, 1978
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-34

                        S METER DRIFT

SEE BULLETIN NO: HW-100-17 DATED AUGUST 22, 1978.
-------------------------------------------------------------------------------------------------------------------
                        SEPTEMBER 26, 1978
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-35

                        POOR IF SENSITIVITY

SEE BULLETIN NO:  HW-100-19 DATED SEPTEMBER 26, 1978.
------------------------------------------------------------------------------------------------------------------
                        OCTOBER 10, 1978
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-36

                            RECEIVER RECOVERY SLOW

SEE BULLETIN NO: HW-100-20 DATED OCTOBER 10, 1978.
------------------------------------------------------------------------------------------------------------------
                        OCTOBER 11, 1978
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-37

                            R-940 SHORTING TO SHIELD

To prevent the leads of R-940 shorting to ground, install a length of
sleeving [PN 346-1] on each lead of R-940.

This will be incorporated in future production.
------------------------------------------------------------------------------------------------------------------
                        OCTOBER 13, 1978
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-38

                          POOR CARRIER SUPPRESSION

The HW-101 carrier suppression specification is -45db or below.  If the
carrier cannot be nulled on both USB and LSB to this level, try changing
R9 on the modulator board from a 1K Ohm to a 390 Ohm [PN 1-48].

This change will reduce the injection level to the balanced modulator and
hence reduce the carrier suppression level.
----------------------------------------------------------------------------------------------------------------
                        NOVEMBER 20, 1978
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-39

                   IDENTIFICTION OF THE 6146A TUBES

The 6146A tubes [PN 411-75] used at V8 and V9 of this unit are marked
'6146A' in white ink on the side of the tube.  These tubes may also have
'6146B' etched in the galss.  These tubes have been reworked by G.E. and
are acceptable for use in the HW-101.  Most tube cartons will contain the
following insert to explain the situation to the customer:

IMPORTANT INFORMATION;
THE TUBE SUPPLIED WITH THIS NOTICE IS TYPE 6146A, AS PRINTED ON ONE SIDE
OF THE TUBE, EVEN THOUGH THERE MAY BE A 6146B ETCHED ELSEWHERE ON THE
TUBE ENVELOPE.

                ALWAYS REPLACE V8 AND V9 WITH 6146A TYPE TUBES

Replace the backing from this label and place the label at any convenient
location inside the cabinet top.
-------------------------------------------------------------------------------------------------------------------
                        NOVEMBER 28, 1978
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-40

        NOISE OR STATIC FROM SPEAKER WHEN CHASSIS TAPPED
                                LIGHTLY

If noise or static is heard from the speaker when the chassis is lightly
tapped, check for intermittent tubes, cold solder connections, or
intermittently shorting filaments in the pilot lamps by tapping each lamp
lightly.  This produces noise in the filament supply but usually will not
produce any difference in the lamp brilliance.
---------------------------------------------------------------------------------------------------------------
                        DECEMBER 11, 1978
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-41

                RELAY CHATTER IN ANY SETTING OF THE VOX SENSITIVITY
                                                               CONTROL

If the relays chatter in the VOX mode, try performing the procedures in
BULLETIN'S HW-101-13, -31 and -38.  If these changes do not correct the
problem, perform the following:

        1.  With a scope, check for excessive noise at the junction
[point 8] of R213 and R214.  Any noise on the white-red-red wires coming
from the mode and function switches will override the reverse bias to
D201, thus activating V12B.

        2.  Replace the two white-red-red wires with shielded cable [PN
343-15].

        3.  Ground the shields to a ground foil near the junction of R213
and R214.
-------------------------------------------------------------------------------------------------------------------
                        DECEMBER 27, 1978
HW-101                                          BULLETIN NO:
SSB TRANSCEIVER                                 HW-101-42

                UNIT "WARBLES" WHEN CHASSIS IS TAPPED

This "warble" has been traced to the VFO assembly.  This occurs
especially when the leads of the C946 and C953 capacitor combination is
too long, enabling the capacitors to vibrate.

To solve this problem, clue the top of C946 [4700pf] to the chassis wall
of the VFO assembly.  The PN 350-12 glue may be used.
--------------------------------------------------------------------------------------------------------------------
                        January 24, 1979
HW-101                                          Bulletin No:
SSB Transceiver                                 HW-101-43

        Poor Sensitivity or Grid or Plate Driver Coils Will Not Tune

Check the lugs that are nearest the chassis and verify that they are not
folded under the capacitors; thus shorting them out.
---------------------------------------------------------------------------------------------------------------
                        January 25, 1979
HW-101                                          Bulletin No:
SSB Transceiver                                 HW-101-44

                        No Ground Pin On Tube Sockets At V10 And V11

The 7-pin tube sockets [PN 434-112] now used at V10 and V11 on the RF
driver circuit board do not have a ground pin in the center.  Only the
7-pin socket [PN 434-129] at V6 on this board uses a ground clip.
---------------------------------------------------------------------------------------------------------------
                        February 16, 1979
HW-101                                          Bulletin No:
SSB Transceiver                                 HW-101-45

                                    VFO Will Not Adjust Properly

If the unit will not track at 0 and 500, or if it will track at 0 and
500, but the error at 100, 200, 300, 400 is greater than specifications,
then make sure the slug in the VFO coil is adjusted to the lower of the
two peaks.  To check, insert the shorter end of PN 490-1 tuning tool into
the coil.  The body of the tool should just touch the top of the coil
form.  If it sticks out a half inch, the coil is at the wrong peak.  Turn
slug into coil and readjust tracking.
------------------------------------------------------------------------------------------------------------------
                        April 25, 1979
HW-101                                          Bulletin No:
SSB Transceiver                                 HW-101-46

                Low Power Output; Poor VOX Sensitivity

See Bulletin No:  HW-100-21 Dated April 25, 1979
--------------------------------------------------------------------------------------------------------------------
                        May 15, 1979
HW-101                                          Bulletin No:
SSB Transceiver                                 HW-101-47

        Driver Preselector Won't Peak For Full Output At 7.0 MHZ

See Bulletin No:  HW-100-23 Dated May 15, 1979
--------------------------------------------------------------------------------------------------------------------
                        May 15, 1979
HW-101                                          Bulletin No:
SSB Transceiver                                 HW-101-48

                    PEC [PN 84-22] No Longer Used

The next production run of HW-101's will use discrete components instead
of the PEC at V15A since the manufacturer will no longer supply this
part.  However, the parts replacement department has a three year supply
of these on hand, so continue to order the PECs if an older unit requires
one.
------------------------------------------------------------------------------------------------------------------
                        May 15, 1979
HW-101                                          Bulletin No:
SSB Transceiver                                 HW-101-49

                      Changeover To 6146B Finals

The 6146A final amplifier tubes are no longer available from the
manufacturer.  Future productions runs will use the 6146Bs.  These are GE
brand tubes and have been tested in the HW-101.  No difficulty was
encountered in neutralizing the finals; nor did the RF choke in the final
plate circuit overheat.  The tube replacement label [PN 390-146] should
be removed from all units brought in for service.
--------------------------------------------------------------------------------------------------------------------
                        July 30, 1979
HW-101                                          Bulletin No:
SSB Transceiver                                 HW-101-50

                        R940 Overheats

In new units, R904 100 ohm [PN 6-101] is a film-type resistor.  During
installation, the body of the resistor may rub against the driver shield,
resulting in the resistor shorting to the shield.  When installing a new
resistor or preworking the unit, position this resistor away from the
shield.
------------------------------------------------------------------------------------------------------------------
                        July 30, 1979
HW-101                                          Bulletin No:
SSB Transceiver                                 HW-101-51

                     Operation of Mode Switch Trips VOX

Dress wht-org-org lead from foil side of modulator board away from V1
foils.

If dressing of this lead fails to correct the problem, install filter in
line with wht-org-org lead.  Use the unused foil at point "A".

(((Shows .024uf connected from wht-org-org to ground --- 2.2K ohm
resistor in line going to R1)))
--------------------------------------------------------------------------------------------------------------------
                        August 15, 1979
HW-101                                          Bulletin No:
SSB Transceiver                                 HW-101-52

                       VFO Stops Working At High End Of All Bands

This problem occures in all modes except LSB.  In LSB, the VFO operates
okay.

To Correct:

        Change:  R947 from 1000 ohm to 470 ohm [PN 6-471]

        Add:  [PN 56-56] diode from gate of Q941 to ground; anode of
diode to gate.
----------------------------------------------------------------------------------------------------------------
                        September 20, 1979
HW-101                                          Bulletin No:
SSB Transceiver                                 HW-101-53

                          Low Transmitter Output; Low Receiver
Sensitivity

When cleaning the unit during prework [tube sockets, potentiometers,
etc.], don't overlook the SSB/CW filter slide switch located with the RF
gain control.  This switch handles both transmit and receive signals and
dirt and grease build-up can affect the performance of both functions.
-------------------------------------------------------------------------------------------------------------------
                        September 27, 1979
HW-101                                          Bulletin No:
SSB Transceiver                                 HW-101-54

                   Receiver Audio Troubleshooting Information

Equipment needed:

        Audio Signal Generator
        Oscilloscope
        01uf capacitor 500 volts or greater [PN 21-16]

Procedure:

        -  connect a 4 ohm load to the speaker jack.
        -  set the AF gain control full clockwise.
        -  set the generator to 1 KHZ at .01 volt RMS
        -  connect the generator to V13, pin 7 through the .01uf
capacitor.

The signal voltages for the points listed shold compare with the values
given below:

        Pin 1 of V14  = 50mv p-p
        Pin 9 of V14  = 1.5v p-p
        Pin 8 of V14  = 1.5v p-p
        Pin 6 of V14  =  35v p-p
        Speaker Jack = .6v p-p

Add these voltages to your shop schematic.
------------------------------------------------------------------------------------------------------------------
                        November 19, 1979
HW-101                                          Bulletin No:
SSB Transceiver                                 HW-101-55

               AVC Decay Too Fast; S Meter Drops Too Quickly

Check for open R117 [PN 6-332]

When replacing this resistor, be sure to dress it away from the AVC wire
ends protruding from the IF board to insure that the wire ends will not
pierce the resistor's film coating.
---------------------------------------------------------------------------------------------------------------
Okay - that's all for the HW-101 that I have.  If I get the 1977 fiche I
will update this.

73 de JOE
- - - - - - - - - - -W7LPF/4 (NNN0KUU)- - - - - - - - - - - - - - -
QWCA - NCVA - SOWP - FISTS
Gordonsville, Va 22942 (Orange County)
Looking for:  Heathkit HR/HX-20, MR/MT-1,
                        CE 100V/200V
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -





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