Heathkit Service Bulletins - SB-230 (Updated & Complete)
Joseph W Lutz
joelutz at JUNO.COM
Thu Jan 15 12:35:49 EST 1998
February 18, 1975
SB-230 Bulletin No:
Linear Amplifier SB-230-1
Power Reduction When Reactivated on 10 Meters
After the linear has been loaded up on 10 meters and allowed to cool for
three minutes, the power might only go up to 200 watts output when
reactivated. After a few seconds [A1 emission key down] the output will
jump up to a normal 550 watts.
Remove the wire from between the rf choke and coupling capacitor C11 and
connect a 14 guage bare wire between the solder lug on C11 and the solder
lug on top of the tube plate cap.
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August 15, 1975
SB-230 Bulletin No:
Linear Amplifier SB-230-2
New Type Delay Tube Socket
A newer type delay tube socket was just procured, using the same part
number [436-56], will have to be mounted from the bottom side of the
chassis, which is contrary to the manual instruction.
The manual will be inserted.
------------------------------------------------------------------------------------------------------------------
September 30, 1976
SB-230 Bulletin No:
Linear Amplifier SB-230-3
Replacing Grid Bypass Capacitors
Replacing gid bypass capacitors can be made much easier by following
these steps:
1. Remove the tube clamp.
2. Remove solder from the capacitor mounting hole, using a desoldering
tool.
3. Clip the old capacitor lead, and unscrew and remove the old
capacitor.
4. Clip a slot in the upper ring of the grid ring capacitor mounting
hole, and bend as shown below.
5. Follow the manual instructions for shaping the new capacitor.
6. Install the new capacitor in the chassis, secure in place, and put
the capacitor lead in the slot in the ring.
7. Bend ring back to shape and solder.
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September 30, 1976
SB-230 Bulletin No:
Linear Amplifier SB-230-4
Improperly Installed
Grid Ring
The grid ring on the #8873 power tube should be checked for proper
installation before power is applied to the linear.
The grid ring may be improperly installed on the ceramic portion of the
tube, and either touches the plate, or allows high voltage to arc over
and destroy the switching diode D17 across the relay. The power supply
diode stack and the PA tube itself, can be easily destroyed.
The grid ring should be installed low enough on the tube to prevent
touching or arching of the high voltage, but not so low that it touches
the metal rivets holding the tube socket.
----------------------------------------------------------------------------------------------------------------
October 18, 1976
SB-230 Bulletin No:
Linear Amplifier SB-230-5
6KV Coupling Capacitor Cannot Be Mounted On Tuning
Capacitor
The [PN 26-144] tuning capacitor has a 6-32 threaded shaft on the upper
left rear end [when viewed from the rear of the capacitor] used to mount
the .001 UF, 6KV [PN 21-165] output capacitor (Refer to P. 47, pictorial
15 of the assembly manual).
Some SB-230's have been shipped with the stud on the opposite side,
leading to incorrect installation of the 10 meter coil if customers
attempt to assemble the unit with the defective capacitor.
The defective [PN 26-144's] should be replaced with capacitors having the
stud on the correct side.
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September 26, 1978
SB-230 Bulletin No:
Linear Amplifier SB-230-6
Meter Scale Not Illuminated
A recent shipment of SB-230 amplifiers, series #05802, has been noted to
have a defective meter [PN 407-185]. The meter scale information was put
on metal rather than clear plastic. As a result, the pilot light will
not shine through to illuminate the meter schale. The meter operates
properly, however.
Replace the defective meter at no charge to the customer.
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September 2, 1980
SB-230 Bulletin No:
Linear Amplifier SB-230-7
RFC 5 Overheats and Circuit Breakers Trip
++++Information not available at this time++++
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April 6, 1984
SB-230 Bulletin No:
Linear Amplifier SB-230-8
Interfacing The Linear To Kenwood Exciters
The ALC voltage to Kenwood transceivers and transmitters should not
exceed -8 volts. To Ensure the proper voltage to the Kenwood, add:
An 8 volt zener diode [PN 56-621] across the ALC connector on the back of
the amplifier. Connect the banded end of the diode to the ground lug.
Adding a control in the ALC line (as instructed in previous bulletins) to
control the level of ALC voltage doesn't always work. This control loads
the ALC line so much that very little ALC voltage is developed, resulting
in the exiter overdriving the linear, In units which have the control
installed and the operation is still unsatisfactory, return the ALC
circuit to its original design and install the zener diode.
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September 12, 1986
SB-230 Bulletin No:
Linear Amplifier SB-230-9
PN 64-24 Safety Interlock Switch NLA
The #64-24 safety interlock switches at SW4 and SW5 are no longer
available from Heath Parts Replacement. The #65-39 lever switch is an
approved substitute. After installing the lever switch, bend the end of
the lever slightly upward so the switch actuates whent he cover is
installed.
-----------------------------------------------------------------------------------------------------------------
September 12, 1986
SB-230 Bulletin No:
Linear Amplifier SB-230-10
[PN 255-164] 4-40 X 5/8" Tapped Spacer NLA
The 4-40 x 5/8" tapped spacer used to mount the pilot lamp bracket is no
longer available from Heath Parts Replacement. Replace the spacer with a
4-40 x 11/16" tapped spacer [PN 255-814] and mount the lamp bracket with
a 4-40 x 1/4" screw [PN 250-1411].
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That's everything I hold up to 1989 that covers the SB-230 . Enjoy!
-------------------------------------------------------------------------------------------------------------------
73 de Joe W7LPF/4 [NNN0KUU]
QWCA - SOWP - NCVA - FISTS - RCC
Gordonsville, Va 22942 [Orange Co]
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