Model 1254 Receiver
TROUBLESHOOTING GUIDE
This section presumes that the receiver has been working and that you now suspect
a problem. Problems encountered DURING kit assembly phases should be corrected
before progressing to the next assembly phase.
1. Look for the simple and obvious first:
Power supply or batter connection problem
Blown power supply fuse
Broken antenna coax connection
Defective headphone or speaker cable
2. Many typical problems can b e resolved by consulting the Troubleshooting
Chart on the following page.
3.
Diagnosis of other possible problems is done best by reviewing the Circuit
Description (Reference Section) and the progress tests after each kit assembly phase.
Selection of correct component values is very important, which is why double-
checking is recommended throughout the building process.
4. If you are not the original builder of the kit, we suggest the following procedures
in this order:
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(Lack of LD voltage indicates PLL or VCO problem.)
Perform the voltage checks including VCO alignment per page 37
Explore any circuit section showing drastically
different voltage readings.
Review the Progress Tests at the end of each Assembly Phase.
Examine boards for cold solder joints, solder bridges,
damaged hookup wire jumpers. Touch up as needed.
Review correct polarity or orientation of all parts.
If none of the above helps, it's time to review the Component Index and kit assembly
phases to see if any incorrect part values were installed. Yes, check every part!
5. Parts Replacement
. The most likely cause of component failure in this circuit
design would be incorrect values installed for some other component(s). Therefore
replacing a bad part should also include the discipline of checking the values installed
for parts immediately associated with that failed component. Also, if you find a
wrong value installed in one place, you should wonder where the correct value was
installed.
Use care and
PATIENCE
in desoldering parts. The plated-through holes make it a
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1254
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Reference - 36
Содержание SSB-CW-AM
Страница 25: ...1254 Assembly 4...
Страница 34: ...Phase 2 0 Assembly begins on page 14 1254 Assembly 13 This space is for your notes...
Страница 35: ...1254 Assembly 14 Phase 2 0 Schematic Diagram Details...
Страница 46: ...This space is for your notes Phase 3 0 Assembly begins on page 26 1254 Assembly 25...
Страница 47: ...1254 Assembly 26 Phase 3 0 Schematic Details...
Страница 57: ...1254 Assembly 36 Phase 4 0 Schematic Details...
Страница 68: ...1254 Assembly 47 This space is for your notes...
Страница 69: ...Phase 5 0 Schematic Details 1254 Assembly 48...
Страница 77: ...Phase 6 0 Schematic Details 1254 Assembly 56...
Страница 93: ...1254 Assembly 72 This space is for your notes...
Страница 101: ...Figure 3R Model 1254 Block Diagram 1254 Reference 8...