Heathkit Service Bulletins - GH Series - (Updated & Complete)
Joseph W Lutz
joelutz at JUNO.COM
Thu Jan 8 22:20:44 EST 1998
July 10, 1968
Amateur Products
Bulletin No.
SB101, 100, HW100
GH-1
Instability -- Trouble
shooting
We suggest you check for each of the following possible causes:
1. Intermittent, rosin or cold solder joints.
2. Loose hardware at the tube sockets, terminal strips, circuit boards,
shields and rear panel sockets.
3. Poor lead dress at tube sockets V8 & V9. The component leads must be
short as possible.
4. Check C925 (Final tune capacitor) to be sure it is isolated from the
tuning shaft. This is to prevent RF from traveling on the shaft to
the front panel.
5. Check all edges of the final enclosures for proper grounding to the
main chassis.
6. Check the hardware for the side rails to be sure a good ground is
being provided.
7. Be sure that all the ground clips on the coil cover are making good
contact with the switch shields.
8. Check the soldering of the switch shields to the center pins of tube
sockets V6, V7, V10 & V11.
9. Check the ground leads from the switch board & shields, to be sure
they are going to ground foil & not to the preselector
capacitor foil pods on the RF driver board.
10. Check for broken or shorted pigtails on each of the shielded cables
in the unit.
11. Check RFC801 & L901 for any signs of deterioration or physical
damage, (burn spots). If apparent replace the part.
12. Improper adjustment of the Het. Osc. coils could cause improper
mixing
action, resulting in the final operating at a different frequency
appearing as instability.
13. Change driver & final tubes then reneutralize per manual
instructions.
14. Check driver tube shield to be sure that it has a good ground
contact with the socket spring clip.
15. Check for a good ground between the front panel & chassis.
16. Check the SWR of the antenna system at the frequency of operation.
Should be below 2:1.
17. Check the antenna coax for leakage, poor connectors & broken shield
connections.
18. Is the transmitter properly grounded?
19. Be sure all shields & tube shields are installed.
20. Realign using a properly terminated 50 ohm non-reactive dummy load.
NOTE: This does not include a light bulb.
21. Check for normal Het. Osc. test-point voltage.
22. Check for proper LMO injection voltage 1.0-1.5 VRF.
23. Check for a high AC ripple content in the LV-B+, HV-B+ and bias
voltages from the power supply.
24. Check to be sure that the shafts do not touch each other in the
insulated
coupling, and that the set screws do not touch the PA shield.
25. Check to be sure that the PA tune shaft turns the variable capacitor
& is not slipping in the insulated coupling.
--------------------------------------------------------------------------------------------------------------------
August 20,
1968
Amateur Products
Bulletin No.
SB & HW Tube Type Transceivers GH-2
Audio Amplifier & VOX Circuit
Troubleshooting
Guide
It is assumed that the basic steps such as making DC voltage measurement,
checking tubes and reviewing the soldering have been completed.
The following information was compiled from the above transceivers in the
80M LSB position. The mike level control was at the 9:00 o'clock
position.
Ac signal voltages are listed below. These voltages were measured from
the microphone connector through the VOX circuit. All measurements were
made with a VTVM. A microphone or audio generator set for .1V at 1KHZ
can be used as the signal source:
Mike Connector Lug 1 .1 VAC
Pin 2 OF V1 .02 VAC
Pin 6 OF V1 10-15 VAC
Lug 4 Level Control 10-15 VAC
Lug 5 Level Control .5 VAC
Pin 9 OF V1 .2 VAC
Pin 8 OF V1 .1-.3 VAC
Center arm of VOX sensitivity control 5-15 VAC
Pin 7 OF V17 5-10 VAC
Pin 6 OF V17 40-50 VAC
Junction of C211-D201 40-50 VAC
Pin 9 OF V12 9-15 VAC
By tracing the AC signal from stage to stage the point of trouble can be
isolated & steps taken to correct it.
Possible trouble areas:
- Check each of the shielded cables for possible open or poorly grounded
shield.
- Check for continuity through each of the shielded cables.
- Check for a proper ground at the mike level control.
If the frequency response of the audio stage is not within specifications
check the value and installation of C1, C2, C3 & C9.
A change in VOX delay after operating for a period of time can be caused
by leakage in diode D201. The other possibility is a change in value of
capacitor C213. Either component could experience a change in
operational characteristics due to heat.
--------------------------------------------------------------------------------------------------------------------
July 7, 1969
Amateur Products
Bulletin No.
SB-101, HW-100 GH-3
Relay Chatter
Prevention of relay chatter can be accomplished by bypassing RF to ground
in VOX circuit. This RF is picked up by mike cables, etc. Install a
.001mfd disc capacitor [PN 21-14) at hole 8 to adjacent ground foil on
bottom of the bandpass circuit board. This point has two red-red-white
wires connected to it also.
--------------------------------------------------------------------------------------------------------------------
October 29, 1970
Amateur Products Bulletin No:
GH-4
SBM-102-1
The attached modification instructions whould be followed to correct the
driver preselector problem of peaking at a different location on receive
than transmit. This is caused by the tube miller effects as explained in
the modification sheet
This should be installed on all units abouve when servicing. SB-102 with
run numbers of 5446 and above should already contain the modification.
Introduction
This modification kit applies to the following Heath Transceivers:
1. All Models HW-100, SB-100, SB-101 and SB-101W.
2. Any Model SB-102 that has a number lower than 5446 as the last four
digits of the series number [on the blue and white label].
The plate tank circuit of V6, the second transmitter mixer, is used in
the receive mode as the plate circuit of V10, RF amplifier. Due to tube
miller effects, additional capacity is required when receiving to permit
the driver preselector to peak at the same dial setting in both transmit
and receive modes. This modification uses automatic diode switching to
add the required compensating capacity.
PARTS LIST
PART QUAN- DESCRIPTION
NO. TITY
------- --------- -------------------
1-26 1 100K ohm, 1/2 watt resistor
1-35 1 1M ohm, 1/2 watt resistor
21-33 1 3.3 pF disc capacitor
56-56 1 1N4149 diode [cathode end marked with a band]
344-50 1 Black hookup wire
391-34 1 Blue & white identification label
431-62 1 3-lug terminal strip
Instruction sheet
Solder
[ ] Remove the cabinet from the transceiver and turn the chassis bottom
side up.
[ ] Remove the coil cover.
[ ] If you wish, temporarily remove the support rail which holds one
end of the switch boards.
[ ] Refer to figure 1 and bend a small "foot" on the end of one lead of
the 100k ohm resistor.
[ ] Coat the "foot" with a liberal amount of solder.
[ ] Solder the foot on the resistor lead directly to the foil at point
11 on the RF
driver circuit board. NOTE: A white-red-red [and possibly other
components] are already soldered to this foil.
[ ] Cut the leads of the 3.3 pF capacitor to 5/8".
[ ] Bend a 1/8" foot on the end of one lead of the disc capacitor and
solder this
foot directly to the foil on the RF driver circuit board at point
X as shown.
Make sure the solder does not short circuit the foil to the switch
shield.
[ ] Connect the cathode [banded] end of the 1N4149 diode to lug 2 of the
3-lug terminal strip [S-1]. Connect the other lead to lug
1 of the terminal strip [NS].
[ ] Connect the 1M ohm resistor from lug 1 [NS] to lug 3 [NS] of the
terminal strip.
[ ] Coat the terminal strip foot with solder.
[ ] Refer to Figure 4 and solder the 3-lug terminal strip directly to
the rearside [driver grid switch board side] of the front switch
shield. Follow the
dimensions given. ((1" from the end of the shield and 1/2" down
from the top
of the shield)). Melt some solder on the switch shield at the
point to
which the terminal strip will be mounted. Then remelt the solder
and hold
the terminal strip foot snugly against the switch shield until the
solder cools.
[ ] Connect the free lead of the 3.3 pF disc capacitor to lug 1 of the
terminal strip [NS].
[ ] Connect the free end of the 100k ohm risistor to lug 1 of the
terminal strip [S-4]. Make sure the capacitor and resistor leads
do not touch any other wires or components.
[ ] Prepare a 16" black hookup wire by removing 1/4" of insulation from
each end of the wire.
[ ] Connect one end of the black hookup wire to lug 3 of the terminal
strip [S-2].
[ ] NOTE: Two sets of steps follow. Use only those steps applying to
your transceiver.
MODELS WITH "SB-" PREFIX:
[ ] Refer to Figure 5 and route the black hookup wire OVER the
bandswitch shaft, as shown, down through grommet CD, and back along
the wiring harness to lug 1 of the Bias Adjust control. Position
the wire against the switch
shield.
[ ] Melt the solder on lug 1 of the Bias Adjust control and push the
bare end of the black hookup wire through the opening in the lug.
After the solder has cooled, tug on the wire to make sure it is
securely connected.
Proceed to the "Final Assembly."
MODEL HW-100:
[ ] Refer to Figure 6 and route the hookup wire over the switch shaft,
through grommet CD, and along the wiring harness to Bias control
CT.
[ ] Melt the solder on lug 1 of control CT and push the bare end of the
hookup wire through the opening in the lug. After the solder has
cooled, tug on the wire to
make sure it is securely connected.
FINAL ASSEMBLY
NOTE: You can secure the hookup wire to the wiring harness with
electrical tape or with short pieces of hookup wire as shown in Figure
7.
[ ] If it was removed, replace the support rail and secure it with the
hardware previously removed. Make sure all switch boards and
shields fit into the proper slots in the comb on the support rail.
[ ] Replace the coil cover. Make sure the grounding clips on the under
side of the cover fit over the switch shields.
[ ] Refer to the alignment section of your assembly manual and peak the
driver grid and driver plate coils.
[ ] Replace the transceiver cabinet.
[ ] Carefully peel away the backing paper from the blue and white
identification label. Then press the label onto the rear of the
cabinet. Be sure to refer to the numbers on this label in any
communications you have with the Heath
Company about this kit.
CIRCUIT DESCRIPTION
A negative voltage is always applied to the anode of D907 from the Bias
Adjust control through resistor R954. When receiving, a higher positive
voltage is applied to the anode of D907 from the screen circuit of V11
through resistor R955. As its anode is now positive, the diode conducts
and acts as a closed switch to supply a ground to C955. This action
places the capacitor is parallel with C421B and adds capacity to the
plate tuned circuit.
In the transmit mode, the positive voltage is removed by the opening of
contacts 3 and 11 of RL2. The remaining negative voltage prevents D907
from conducting and it consequently acts as an open switch, removing the
ground from C955. The capacitance of C955 is therefore removed from the
plate circuit of V6.
------------------------------------------------------------------------------------------------------------------
June 2, 1976
Amateur Products Bulletin No:
GH-5
Amateur Products
Item not found on 1976 microfiche.
--------------------------------------------------------------------------------------------------------------------
October 1, 1979
General Ham Bulletin No:
GH-6
Power Supply Connector Quick Reference Chart
Power supply connector Quick Reference Chart
Many technicians have requested a consolidated parts list showing a
transceiver power supply connector and its mate on the cable and power
supply. Usually these are not listed in the same manual.
The following chart provides a quick reference for the power supply
connectors and their associated hardware for the more common tranceivers.
SERIES CONNECTORS
HW/SB Series 8 Pin: PN 438-6 [Male] PN 434-4
[Female]
11 Pin: PN 438-29 [Male] PN 434-118
[Female]
Mounting ring [both 8 & 11]: PN 435-1
Cap [both 8 & 11] : PN 440-1
......................................................................................................................................................
HP-13 Female: PN 432-35 Male: PN
432-34
......................................................................................................................................................
Small terminal (HW-202, HW-2036, etc):
Male: PN 432-72 Female: PN 432-73
Large terminal (HP-1175):
Male: PN 432-862 Female: PN 432-863
HA/HP/HW/PS Series
Small terminal housing:
Male: PN 432-720 Female: PN 432-723
Large terminal housing:
Male: PN 432-886 Female: PN 432-887
........................................................................................................................................................
PN 347-13 2 wire [HP13]
PN 347-52 8 wire [all]
PN 423-10 Fused lead [12 volt systems; HP-13, HW-202, etc.].
PN 344-16 Red cable [12 volt systems; HW202, HW-2036, etc.].
PN 344-15 Black cable [12 volt systems; HW-202, HW-2036, etc.].
-------------------------------------------------------------------------------------------------------------------
January 21, 1980
General Amateur Bulletin No:
GH-7
Universal Extender Card For HR-1680, HW-104, HX-1681,
SB-104, SB-303 and SB-313
+ + + +Information not available at this time+ + + +
-------------------------------------------------------------------------------------------------------------------
May 8, 1981
General Amateur Bulletin No:
GH-8
Crystal Filter Information For HW/SB/HX Series
+ + + +Information not available at this time+ + + +
-------------------------------------------------------------------------------------------------------------------
January 16, 1987
General Amatuer Bulletin No:
GH-9
ICOM Transmitter Anternna Relay Contacts Fail When Connected
To Antenna Relay Jack On Heath Linear Ampliers
The 120 VDC at the Linear Amplifier antenna jack exceeds the 24 VDC
maximum rating of the antenna relay contacts in the ICOM transmitter.
This excess voltage causes the relay contacts in the ICOM transmitter to
weld together. To prevent this, connect the ICOM transmitter to the
Linear Amplifier using a 12 VDC as shown in the drawing below.
. \.______>Ant Relay Heath
|________> Jack
Linear
ICOM>_________________
Amplifier relay 3 +12v
jack <____ 3 Coil
| 3
+12 V |
| |
GND GND
((Sorry for the poor drawing - just another reason to get the scanner
working))
A relay box for this purpose is available for ICOM America, Inc.
--------------------------------------------------------------------------------------------------------------------
September 30, 1987
General Amateur Bulletin No:
GH-10
As of March 21, 1987, the novice class licensee can now be the control
operator of an amateur radio station that operates on the following
frequencies:
3700 to 3750 kHz
7100 to 7150 kHz
21.100 to 21.200 kHz
28.1 to 28.5 MHz
222.1 to 223.91 MHz
1270 to 1295 MHz
The new novice privileges are defined as follows:
Frequency Modes Restrictions
-------------- --------- -----------------
28.1 to 28.5 MHz CW and RTTY 200 watts PEP max
28.3 to 28.5 MHz CW and SSB 200 watts PEP max
222.1 to 223.91 MHz All* amateur 25 watts PEP max
privileges authorized
on this band
1270 to 1295 MHz All* amateur 5 watts PEP max
privileges authorized
on this band
*Novices are not permitted to be repeater control operators.
--------------------------------------------------------------------------------------------------------------
Thats everything I hold up to 1989 that covers GH [General Amateur].
--------------------------------------------------------------------------------------------------------------
73 de Joe W7LPF/4 [NNN0KUU]
QWCA - SOWP - NCVA - FISTS - RCC
Gordonsville, Va 22942 [Orange Co]
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