Sine Systems RFC-1/B Instruction Book

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/l\ WARNING!
Because the RFC-1 is an FCC registered device, it must not be
modified in any way. Any components which are replaced must be replaced with ones of
exactly the same type and rating. This is particularly critical in the circuitry involving
connection to the telephone line. Unless repair is performed by a properly qualified
technician, it is strongly recommended that the RFC-1 be returned to Sine Systems for repair
if a failure has occurred in this area. Your safety and the safety of others could depend on it!
Additional useful information concerning the technical operation of the RFC-1 is located in
the "Circuit Description" chapter of this manual. A summary of troubleshooting hints is
included after the following general service information on the RFC-1 and RP-8 .
Fuse Replacement
Later versions of the RFC-1 contain no conventional fuses. In place of the four fuses used in
earlier versions, self-resetting fuses called "Polyswitches" are used instead. They protect the
RFC-1 from over-current just like fuses, but, in normal use. they never have to be replaced.
In some cases, in order to reset the Polyswitches, it will be necessary to disconnect the 12 volt
AC power supply for a few seconds. Polyswitches have current ratings just like fuses and if
they are ever replaced, be sure and replace them with the same type and rating.
RF Problems
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There have been very few reported RF problems with the RFC-1 associated with FM
transmitters. The RFC-1 has been tested and found to operate satisfactorily in AM RF fields of
632 volts/meter (the ANSI limit for human exposure) with no additional external filtering.
However, extreme conditions have been documented that required additional external filtering
to obtain reliable operation. In one such case, touching an exposed conductor of the
telephone line produced a painful shock and RF bum. Such extreme conditions are rare but
even these problems can be overcome by a combination of one or more of the following
remedies:
1) Install an RF filter preceding the "LINE" jack near the RFC-1
2) Install an RF filter preceding the ’ TELEPHONE" jack near the RFC-1
3) Loop the ribbon cable several times through a ferrite core near the RFC-1
and another near the relay panels.
A typical telephone line RF filter is made by Suttle Apparatus, P.O. Box 28, Lawrence, IL,
62429. Their telephone number is (618) 943-5721. These can be be obtained through a
wholesale distributor of telephone products. Be sure you get an RF filter and not simply a
telephone ’ spike ’ protector. Ferrite cores suitable for ribbon cable are available from Radio
Shack (part number 273-104).
Power Supply
The first step in troubleshooting should be to look for signs of burned or otherwise damaged
parts. It is normal for U8, U9 and D6 to run fairly warm but they should not be hot enough
to burn or discolor the PC board. Next, check the incoming AC voltage and the four power
supply voltages. Note that the "+10 volt" supply is unregulated and may be anywhere from 9
to 11.5 volts DC.
3.01.1
Troubleshooting and Repair
page 7.3

Sine Systems RFC-1/B Specifications

General

Brand	Sine Systems
Model	RFC-1/B
Category	Remote Control
Language	English