Heathkit Service Bulletins - HW-2036 (Complete 1966-89)

Joseph W Lutz joelutz at JUNO.COM
Wed May 6 11:23:13 EDT 1998


                        February 4, 1977
HW-2036                                                 Bulletin
No:
2-Meter Transceiver                                     HW-2036-1

                       Blowing RF Fuse in Alignment Generator

+ + + + Information not yet available + + + +
-------------------------------------------------------------------------------------------------------------------
                        February 14, 1977
HW-2036                                                 Bulletin
No:
2-Meter Transceiver                                     HW-2036-2

                                  Low Power Output

+ + + + Information not yet available + + + +
--------------------------------------------------------------------------------------------------------------------
                        March 7, 1977
HW-2036                                                 Bulletin
No:
2-Meter Transceiver                                     HW-2036-3

                  Troubleshooting Low Sensitivity

+ + + + Information not yet available + + + +
--------------------------------------------------------------------------------------------------------------------
                        March 16, 1977
HW-2036                                                 Bulletin
No:
2-Meter Transceiver                                     HW-2036-4

                       Synthesizer Lock Instability

+ + + + Information not yet available + + + +
--------------------------------------------------------------------------------------------------------------------
                        March 16, 1977
HW-2036                                                 Bulletin
No:
2-Meter Transceiver                                     HW-2036-5

                      Power Drops Off When Installed in Case

+ + + + Information not yet available + + + +
-------------------------------------------------------------------------------------------------------------------
                        May 25, 1977
HW-2036                                                 Bulletin
No:
2-Meter Transceiver                                     HW-2036-6

         Units Fails to Lock Until 0-5 kHz Switch is Actuated

+ + + + Information not yet available + + + +
------------------------------------------------------------------------------------------------------------------
                        May 25, 1977
HW-2036                                                 Bulletin
No:
2-Meter Transceiver                                     HW-2036-7

                        Crystal Check

+ + + + Information not yet available + + + +
-------------------------------------------------------------------------------------------------------------------
                        July 8, 1977
HW-2036                                                 Bulletin
No:
2-Meter Transceiver                                     HW-2036-8

                           Improve IF Response

+ + + + Information not yet available + + + +
------------------------------------------------------------------------------------------------------------------
                        July 11, 1977
HW-2036                                                 Bulletin
No:
2-Meter Transceiver                                     HW-2036-9

        Synth Goes Out of Lock at Anything Over a Low-Listening
                               Level

+ + + + Information not yet available + + + +
-------------------------------------------------------------------------------------------------------------------
                        July 27, 1977
HW-2036                                                 Bulletin
No:
2-Meter Transceiver                                     HW-2036-10

                Conducted Spurious Modification

+ + + + Information not yet available + + + +
--------------------------------------------------------------------------------------------------------------------
                        September 14, 1977
HW-2036                                                 Bulletin
No:
2-Meter Transceiver                                     HW-2036-11

                               L201 Tuning Peak at Bottom of Coil

+ + + + Information not yet available + + + +
--------------------------------------------------------------------------------------------------------------------
                        September 21, 1977
HW-2036                                                 Bulletin
No:
2-Meter Transceiver                                     HW-2036-12

                               Sync Won't Lock, No TX

+ + + + Information not yet available + + + +
--------------------------------------------------------------------------------------------------------------------
                        November 17, 1977
HW-2036                                                 Bulletin
No:
2-Meter Transceiver                                     HW-2036-13

                       High Internal Spurious Levels in Receiver

+ + + + Information not yet available + + + +
--------------------------------------------------------------------------------------------------------------------
                        March 14, 1978
HW-2036                                                 Bulletin
No:
2-Meter Transceiver                                     HW-2036-14

        Reduce Receiver Spurs and Reference Tone in Transmit

The following changes are recommended to reduce receiver spurs and
objectionable levels of 833 Hz reference tone in transmit signal.

You maynot notice a significant reduction in the reference tone level if
it is already low.  The "mod" will reduce the objectionable levels
approximately 10 dB.

Parts Required: 1 ea    #8 solder lug [PN 2959-24]
                1 ea    #6 solder lug [PN 259-1]
                1 ea    100 pF capacitor [PN 21-75]
                2-1/2"  Small red stranded wire [PN 344-90]
                3/4"    Small sleeving [PN 346-1]

Transmitter Board:

- Change C403 from .001 uF to 100 pF [PN 21-75].

- Remove the red wire and one lead of C2 [.001 uF] from point S. Save the
two
   ferrite beads from the lead of C2.

-  Remove C2 and discard.

-  Solder PCB pins B, L and N to the foil on the TOP side of the
Transmitter board.

-  Splice the 2-1/2" red stranded wire onto the red wire that was removed
from
    point S.  Place sleeving over the splice.

-  Connect the red wire to the OUT PCB pin.  Wrap the end of the wire
around the
    top of the pin and solder.

Power Amplifier Board

- Prepare the #8 solder lug [PN 259-24]  (At 9/16" bend the eyelet end of
the solder lug at a 90 deg angle.  Then cut off the end 1/2" from the
bend.]

-  Mount the #8 solder lug and the #6 solder lug at point X, as shown.
//The #8     solder lug is shown connected to the chassis with following
sequene: washer,
    #8 lug, #6 lug, nut.  The bent 'foot' of #8 is then soldered to the
chassis.//

-  Solder the #8 solder lug to the chassis.

-  Remove the shield lead of the coax cable at point B on the Power
Amplifier     board.  Then solder this shield lead to the #6 solder lug
at point X.

NOTE:  When checking receiver spur levels, a 50 ohm impedance must be
connected to the antenna input jack.
-------------------------------------------------------------------------------------------------------------------
                        April 14, 1978
HW-2036                                                 Bulletin
No:
2-Meter Transceiver                                     HW-2036-15

                       No VCO Lock (Temperature Related)

QA has looked into this problem and has determined that NPC or NP devices
should NOT be used for Q501, Q503 or Q401.  All other manufacturers of
Part # 417-801's are acceptable replacements.  (NPC or NP devices are
clearly marked; factory parts inventory does not contain NPC devices).
-----------------------------------------------------------------------------------------------------------------
                        May 30, 1978
HW-2036                                                 Bulletin
No:
2-Meter Transceiver                                     HW-2036-16

                Wrong Diode Installed At VD-502

Diode VD-502, on the VCO circuit board, should be an MV-2110 [PN 56-640].
 This diode is packed in a special bag marked "HW-2036A".  The MV-2107 is
packed with the VCO parts and may have been used at this location.

Also check R302 on the Power Amplifier circuit board.  This resistor
should be a 100 K ohm, 5 % [PN 6-104-12], instead of a 10 %.
--------------------------------------------------------------------------------------------------------------------
                        July 24, 1978
HW-2036                                                 Bulletin
No:
2-Meter Transceiver                                     HW-2036-17

                   Receiver Spurs On Repeater Frequencies

A number of receier spurs are present in the HW-2036 and HW-2036A.  When
the 10 MHz and 21.55 MHz oscillators are correctly set per the manual,
several of these spurs will occur on standard repeater channels, i.e.,
147 MHz.

These spurs may be moved off channel by adjusting the 10 MHz oscillator
high or low by some [change of] f, and compsensating at the center of the
band by readjusting the offset oscillators (receiver and transmit).  The
spurs will move approximately 1500 Hz for every 100 Hz [change of] f, and
in the same direction as [change of] f.  For example, if the 10 MHz
oscillator is set 500 Hz high, the spur at 147 MHz will move up to
147.0075 MHz.  The offset oscillators must be adjusted in the opposite
direction by 0.1 [change of] f for the HW-2036A, or by 0.117 [change of]
f for the HW-2036.  (The offset oscillator does not affect spur
frequencies.)

The price to be paid is a frequency error, which will be maximum at the
band edges.  This maximum error will be 1/5 [change of] f in the
HW-2036A, and 1/10 [change of] f in the HW-2036.  For example, if [change
of] f = 1 kHz, maximum error = 200 Hz in the HW-2036A, 100 Hz in the
HW-2036.  This is less than 0.00015% or 1/10 of the stability
specification, and should be an acceptable trade-off to a customer
bothered by a spur.

The procedure is as follows:

        1.  Tune to the offending spur.
        2.  With dummy load attached, adjust the 10 MHz oscillator just
enough
              to drop the spur to an acceptable level.
        3.  Set switches to center of band.
        4.  Adjust offsets by following one of the procedures in the
manual.
        5.  Check to see that no spurs have moved onto other desired
channels.
-------------------------------------------------------------------------------------------------------------------
                        July 24, 1978
HW-2036                                                 Bulletin
No:
2-Meter Transceiver                                     HW-2036-18

                        No FM Quieting

If there is no FM quieting, although deviation can be heard at .5 uV and
signal strength meter deflects normally, check:

        IC502, the VCO oscillator chip [PN 443-740].

It may be noisy, causing high noise injection at the first receiver mixer
stage.
-------------------------------------------------------------------------------------------------------------------
                        July 24, 1978
HW-2036                                                 Bulletin
No:
2-Meter Transceiver                                     HW-2036-19

        PLL Will Not Lock; Cannot Adjust TP401 to 2.2 Volts

Some early "A" models were shipped with incorrect VCO coils and incorrect
capacitors for C509 and C513.

If the VCO test voltage at TP401 changes rapidly between .5 and 4.5
volts, check these components,  The correct parts are:

        VCO coil, blue [PN 49-1855]
        C509; 22 pF capacitor [PN 20-99]
        C513; 125 pF capacitor [PN 20-177]
--------------------------------------------------------------------------------------------------------------------
                        September 26, 1978
HW-2036                                                 Bulletin
No:
2-Meter Transceiver                                     HW-2036-20

                Synthesizer Circuit Board [PN 85-1877-4] Screening
                                       Inconsistencies

Note the following screening errors:

Component Location      Correct Value   Value Screened on Board
-----------------------------   -------------------     ------------------------------------
R447                    820 Ohm         470
R445                    2200 Ohm        6800
C403                    100 pF ceramic  .001
----------------------------------------------------------------------------------------------------------------
                        October 11, 1978
HW-2036                                                 Bulletin
No:
2-Meter Transceiver                                     HW-2036-21

                        Low Power Output

After the unit has been operating for a period of time, L106 and L107 may
not tune properly and there will be low RF voltage at T1, along with low
power output.  The center conducter of J102 on the transmitter circuit
board may be cutting the insulator paper below the circuit board (on the
chassis) thus shorting the RF to ground.

If the lower washers on the board mounting studs are missing, the board
will rest too close to the chassis, which causes the jack to come in
contact with the chassis and insulator paper, eventually shorting to the
chassis.

Be sure the lockwashers are properly installed and if need be, the center
lug of J102 may be trimmed slightly to provide additional clearance.
------------------------------------------------------------------------------------------------------------------
                        November 20, 1978
HW-2036                                                 Bulletin
No:
2-Meter Transceiver                                     HW-2036-22

        Part # 417-240 FET's Supplied With Shorting Wire On Leads

This unit may have been shiped with a shorting wire around the leads of
the Part # 417-240 device.  The manual does not give instructions to the
customer for the removal of this shorting wire.

When servicing this product, check for the possibility of the shorting
wire still installed on this device.

The manual is being inserted with the proper instructions concerning the
removal of the shorting wire.
------------------------------------------------------------------------------------------------------------------
                        January 9, 1979
HW-2036                                                 Bulletin
No:
2-Meter Transceiver                                     HW-2036-23

          Relative Receive Signal Strength Meter Inoperative But
                       Receiver Sensitivity Meets Specifications

Q204 [PN 417-169] is defective.  Typical meter operation is 2 -5 uV for
full scale deflection.
-------------------------------------------------------------------------------------------------------------------
                        February 16, 1979
HW-2036                                                 Bulletin
No:
2-Meter Transceiver                                     HW-2036-24

        Pilot Lamp Holder Interferes With Removal And Installation
                            Of VCO Cover

The pilot lamp holder mounted on the VCO cover jams against the front
panel, making it difficult to remove and install the VCO cover.

To correct, modify the lamp holder as follows:

1)  Remove VCO cover.

2)  Cut lamp holder, (approximately in the center of where the lamp was
previously
      held).

3)  Dress sharp edges with file.

4)  Press lamp into modified holder [I.E., snap down against the VCO
cover].

5)  Install Cover.
--------------------------------------------------------------------------------------------------------------------
                        April 3, 1979
HW-2036                                                 Bulletin
No:
2-Meter Transceiver                                     HW-2036-25

                Loss of Sensitivity in Cold Climates

To correct this problem, change:

        C224 and C227, from 01 uF to .1 uF [PN 21-95].

Make this change only as needed.
-------------------------------------------------------------------------------------------------------------------
                        June 18, 1979
HW-2036                                                 Bulletin
No:
2-Meter Transceiver                                     HW-2036-26

                        Receiver Will Not Squelch

If the receiver appears to operate normally otherwise, connect a
frequency-modulated signal generator (1 kHz @ 5 kHz deviation) to the
antenna jack and monitor the output of IC202 with an oscilloscope.  If
the waveform is non-symmetrical, then check for a defective C233 [PN
21-7].
--------------------------------------------------------------------------------------------------------------------
                        July 31, 1979
HW-2036                                                 Bulletin
No:
2-Meter Transceiver                                     HW-2036-27

                Synthesizer Light Will Not Go Out

If the voltage at TP401 has very limited range as L501 is adjusted, and
the synthesizer light will not go out even when TP401 is at 2.2 volts,
check C416, a 2.2 uF tantalum capacitor [PN 25-221] for being shorted.
-------------------------------------------------------------------------------------------------------------------
                        November 19, 1979
HW-2036                                                 Bulletin
No:
2-Meter Transceiver                                     HW-2036-28

        Synthesizer Only Locks Over A Limited Range; Difficult To
                                 Adjust

Check the 2.2 uF tantalum capacitor at C416 [PN 25-221].  It may be
leaky.
-------------------------------------------------------------------------------------------------------------------                             January
21, 1980
HW-2036                                                 Bulletin
No:
2-Meter Transceiver                                     HW-2036-29

         Poor Receiver Sensitivity; Synthesizer Lock May be Erratic

+ + + + Information not yet available + + + +
--------------------------------------------------------------------------------------------------------------------
                        April 23, 1980
HW-2036                                                 Bulletin
No:
2-Meter Transceiver                                     HW-2036-30

            High-Level Reference Signal at Even Frequencies
                    (146.00, 147.00, 148.00, etc)

+ + + + Information not yet available + + + +
--------------------------------------------------------------------------------------------------------------------
                        August 13, 1980
HW-2036                                                 Bulletin
No:
2-Meter Transceiver                                     HW-2036-31

                           Drops Out of Lock in Transmit Mode

+ + + + Information not yet available + + + +
-------------------------------------------------------------------------------------------------------------------
                        June 8, 1981
HW-2036                                                 Bulletin
No:
2-Meter Transceiver                                     HW-2036-32

               Transmitter Modulated with 833.333 Hz Reference
                             Signal

+ + + + Information not yet available + + + +
-------------------------------------------------------------------------------------------------------------------
                        October 31, 1983
HW-2036                                                 Bulletin
No:
2-Meter Transceiver                                     HW-2036-33

                          Motorboating in Receiver Audio Output

+ + + + Information not yet available + + + +
-------------------------------------------------------------------------------------------------------------------
That's all I show listed for the HW-2036 (1966-89).  Enjoy!


73 de Joe  W7LPF/4  [NNN0KUU]
QWCA - SOWP - NCVA - FISTS - RCC
Gordonsville, Va 22942 [Orange Co]
Wanted:  SB-614 & SB-644[A]

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