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                        Kenwood Service Centers

   Kenwood Service Corporation             Kenwood Service Center, East
   2201 East Dominguez Street              829 Lynnhaven Parkway, Suite 130
   Long Beach, California 90801            Virginia Beach, Virginia 23452
   Telephone 1-310-639-5300                Telephone 1-804-340-1702

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BULLETIN # 917
MODEL: TS-940S
SUBJECT: VCO CARRIER TO NOISE RATIO IMPROVEMENT 

The Carrier to Noise ratio of the TS-940S may be improved by the
following changes. This bulletin supersedes bulletin number 911 dated
September 15. 1986

	Parts required:
	PLL UNIT (X50-2020-00)

	R120,129 3.3K ohm 1/6 watt carbon resistor	RD14CB2C332J
	R121,124 680 ohm 1/6 watt carbon resistor	RD14CB2C681J
	C180,181 .01 uF disc ceramic capacitor  	C91-0117-05
	C184,185 .33 uF 35v Tantalum capacitor	        CS15ElVR33M

	RF UNIT (X44-1660-00)
	R154,155 3.9K ohm 1/6 watt carbon resistor	RD14BB2C332J
	C193,194 1 uF 25v Tantalum capacitor	        CS15ElEOlOM

Procedure:

On the PLL UNIT (X50-2020-00) remove capacitors C176, C180, and C181. 
Change resistors R120 and R129 from 470 ohms to 3.3 K ohms. 
Change resistors R121 and R124 from 1 K ohm to 680 ohms. 
Change capacitors C184 and C185 from .22 uF to .33 uF 35v tantalums 
Instal1 C180 and C181 in the positions shown in the accompanying diagrams. 
The use of new capacitors is recommended to improve reliability, 
don't try to reuse the old capacitors! 
Capacitors C181 and C180 should be attached to the foil side of the PLL unit


On the RF Unit (X44-1660-00) install the series RC circuits composed of 
R154 and C193, and R155 and C194, as shown in the accompanying diagrams. 
As the diagrams illustrate it is easiest to move C132 and C133 to the 
foil side of the board and install the series RC circuits on the component 
side.

Time required for this modification is 1.5 hour or less.