Vectronics VEC-254 User Manual

VEC-254 Owner's Manual Classroom Code Practice Oscillator
INTRODUCTION
The VEC-254 is the finest keyed oscillator on the market. Its professional quality is well suited for demanding classroom use and abuse. The VEC-254's unique design removes any harsh key clicks. Making the VEC-254 a perfect complement to any keyer paddle. This unit enhances classroom instruction of Morse Code by delivering a full watt of power to the internal 3 inch speaker.
FRONT PANEL
Power (On/Off)................................Power Switch
Volume............................................Volume Control
Tone ................................................Tone Control
Pwr..................................................Power Indicator
Key Input.........................................1/4" Phone Jack
REAR PANEL
Power...............................................2.1mm Coaxial Jack
Ext. Speaker ....................................3.5mm Speaker Jack
OPERATION
The VEC-254 requires a 12V source for power operation. The power jack accepts a 2.1mm coaxial type plug with the outside sleeve as the ground pole and the inside as the positive po le. Apply power to the unit by plugging a power adapter to the jack on the back of the unit labeled "Power". With the switch in the Off position (out), connect a keyer paddle to the "Key Input" of the VEC-
254. The Key Input requires a 1/4" mono or stereo plug with a 2-conductor wire from the keyer. The sleeve is connected to ground and the other wire is connected to the tip. Once the power and keyer have been attached, the VEC­254 is ready to use. Push in the power switch to the On position and verify that the indicator labeled "Pwr" is lit.
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VEC-254 Owner's Manual Classroom Code Practice Oscillator
WARNING: Do Not Place The Output Speaker Of This
Unit In Close Proximity To Your Ears. The Amplification On This Unit Is Very High And Could Cause Damage.
The volume control for the VEC-254 is located on the front of the unit. To increase the output volume, push in the power switch to the On position, key the keyer and turn the knob labeled "Volume" in the clockwise direction. The tone control is also located on the front of the unit. With the volume at a comfortable level and the keyer keyed, adjust the tone by varying the knob labeled "Tone".
To use the VEC-254 with the optional external speaker, plug a speaker, with a
3.5mm plug, into the jack labeled "Ext. Speaker". This jack is located on the back of the unit.
The VEC-254 comes with a trimpot to generate a symmetrical rise time and fall time of the input signal. This feature eliminates the unwanted key clicks that are normally heard fr om keyers. The setting on this trimpot (R20) is made at the factory and should not be changed.
TECHNICAL ASSISTANCE
If you have any problem with this unit first check the appropriate section of this manual. If the manual does not reference your problem or your problem is not solved by reading the manual you may call VECTRONICS at 601-323-5800. You will be best helped if you have your unit, manual and all information on your station handy so you can answer any questions the technicians may ask.
You can also send questions by mail to VECTRONICS, 1007 HWY 25 South, Starkville, MS 39759 or by Fax to 601-323-6551. Send a complete description of your problem, an explanation of exactly how you are using your unit, and a complete description of your station.
PARTS LIST
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VEC-254 Owner's Manual Classroom Code Practice Oscillator
P/N DESCRIPTION REFERENCE
100S-2100 100S-3100 100S-3390 100S-3470 100S-4100 100S-4270 100S-4470 100S-5150 100S-5330 130-5100 155-3100-1 155-4100-1 200S-1110 200S-1122 200S-1210 203-1470 203S-3110 300S-0914 1N4148 SWITCHING DIODE D1,D2,D3,D4 305-7002-SM 2N7002 TRANSISTOR Q1 307-1020 +8V VOLTAGE REGULAR U2 311-0040-SM LM324 OP AMP U1 311-27052 TDA7052AN AUDIO AMP U3 320-1002 3mm RED LED CR1 410-0169 504-0022 2P2T PUSH BUTTON SWITCH SW1 601-0012 1/4" PHONE JACK J3 601-5005 3.5mm CLOSED STEREO JACK J2 601-6021 2.1mm COAXIAL, POWER JACK J1
100 RESISTOR 1K RESISTOR
3.9K RESISTOR
4.7K RESISTOR 10K RESISTOR 27K RESISTOR 47K RESISTOR 150K RESISTOR 330K RESISTOR 100K TRIMPOT 1K POT 10K POT .01 µF CAPACITOR .022 µF CAPACITOR .1 µF CAPACITOR 470 µF, ELECTROLYTIC CAPACITOR 1 µF CAPACITOR ELECT
3" 8 SPEAKER
R17 R4,R11,R14 R7 R2,R13 R1,R6,R8,R12,R16 R5 R9,R10 R3 R15 R20 R22 R21 C6 C2,C3 C4,C5 C7,C8 C1
SPK1
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VEC-254 Owner's Manual Classroom Code Practice Oscillator
SCHEMATIC
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