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Heathkit SB-101 - ah.1.62. HW-101-58: Receiver Oscillations

Heathkit SB-101
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Perform the suggestions in TEBs HW-101-31 and HW-101-41. If this doesn’t correct the
problem, then install two 0.1 uF capacitors [PN 27-28] across R308. This will reduce
pulse rise time and improve VOX operation. Note: In some older transceivers, it may be
necessary to add a higher value capacitor; perhaps as high as 0.47 uF.
Perform this modification on an "as-needed" basis.
ah.1.62. HW-101-58: Receiver Oscillations
JANUARY 21, 1980
HW-101 BULLETIN NO: SSB TRANSCEIVER HW-101-58
The following symptoms may be present:
- The S meter deflects upscale when the CW filter is switched in.
- Oscillations occur with the RF Gain control at maximum and the Bandswitch is
changed.
- Oscillations may die out after three to four minutes.
To correct, retune T103 [PN 52-79] to it’s top peak. (This may also give you more audio
output.)
ah.1.63. HW-101-59: Finals Will Not Neutralize; C913 at Maximum Capacity
MARCH 7, 1980
HW-101 BULLETIN NO: SSB TRANSCEIVER HW-101-59
Check for missing bare wire between Driver Plate board and RF-Driver board at location
shown in drawing below.
[[Looking down at the RF-Driver Circuit Board - the Driver Plate Circuit Board is
‘bonded’ to it, by the short bare wire at a location on the PCB’s approximately half-way
between the right side of the chassis and the switch shaft that passes through the Driver
Plate CB]]
If the bare wire is missing, install a 11/16 inch large braid [PN 345-1] between these two
boards. If a bare wire is already installed, replace with the braid to improve reliability.
In either case, be sure the braid doesn’t short to adjacent foils.
ah.1.64. HW-101-60: RF Mod in CQ Magazine
APRIL 10, 1980
HW-101 BULLETIN NO: SSB TRANSCEIVER HW-101-60
The March, 1980 issue of CQ Magazine ran an article on interfacing the HW-101 to a
Drake 2B receiver. Among other things, the article implied that Heath Company is
HW-101 Service Bulletins Page 152

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