92 lines
4.1 KiB
Plaintext
92 lines
4.1 KiB
Plaintext
SHORTWAVE CONVERTER
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Parts List
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C1 Optional capacitor. Use 150pF with 5 Mhz crystal, or 47pF with 8 Mhz
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If using crystal ò 10 Mhz omit this capacitor.
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C2 33 pF
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C3,C5 220 pF
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C4 .047 æF
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D1 Zener diode between 5.1v - 6.2v (2N4691 or equivalent)
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R1 1Kê, ¬ watt resistor
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U1 NE602N Frequency Converter IC
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T1 10.7 Mhz miniature IF transformer (green core)
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XTAL 5 Mhz or 8 Mhz crystal, or other values (see text file XTAL.TXT)
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One for each band you like to listen to
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8-pin DIP socket (for U1)
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J1,J2 RCA jacks [J2 is optional, see note 3 below]
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Motorola plug (optional. If installing converter externally, use for
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connecting cable to car radio's antenna jack). Radio Shack parts #274-711
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14-pin wire-wrap socket and 14-pin DIP headers for mounting crystals
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Optional (see file XTAL.TXT)
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Hookup wire
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Schematic
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=========
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ÚÄÄÄÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÄÂÄÄÄÄÂÄÄ/\/\/\Ä +12v
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³ ÄÄÁÄÄ ³ ³ R1
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ÄÁÄC3 ÚÄÄÄ¿ xtal ³ ³
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ÄÂÄ ÀÄÄÄÙ ³ ³
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³ ÄÄÂÄÄ ³ ³
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J2 (to car radio antenna jack) ³ ³ ³ ³
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ÚÄÄ¿ C5 ÚÄÄÁÄÄÄÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÄÁ¿ ³
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³ oÄÄÄÄÄÄÄĶÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ´ 7 6 8³ ³
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ÀÄÂÙ ³5 ³ ³
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ðgnd ³ U1 ³ ³
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³ ³ ³
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J1 (ant.) ÚÄÄÄÄÄÄÄÄÄ¿ ³ NE602 ³ ³ ¿ D1
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ÚÄÄ¿ ³ 3ÃÄÄÄÄÄÂÄÄÄÄ´ ³ ÃÄÄÄÄ´ÄÄÄÄÄÄÄÄ¿
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³ oÄÄÄÄÄÄÄÄ´1 ³ ³ ³ Frequency ³ ³ À ³
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ÀÄÂÙ ³ T1 4ÃÄnc ÄÁÄC1*³ Converter ³ ³ ³
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³ ³ ³ ÄÂÄ ³ ³ ³ ³
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ÃÄÄÄÄÄÄÄÄ´2 ³ ³ ³ ³ ÄÁÄ ³
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³ ³ 5ÃÄÄÄÄÄÁÄÄÄÄ´ ³ ÄÂÄ C4 ³
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³ ÀÄÄÄÄÄÄÄÄÄÙ ³ 3 ³ ³ ³
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³ ÀÄÄÄÄÄÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÄÄÄÙ ³ ³
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³ ³ ³ ³
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ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ
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ðgnd
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-----------------------------
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Notes:
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1) Virtually any construction method (point-to-point wiring, wire wrapping,
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etc.) should work, but a printed circuit board is recommended for both
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ease and neatness of construction. PC board construction would probably
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also help minimize undesirable RF interference from strong local broadcast
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stations. See file READ.ME for source of PC board.
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2) Connect external antenna to J1 (it works with anything over 2', but better
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results are obtained with longer lengths.
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3) J2 connects to car radio's antenna jack. If mounting the converter inside
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the car radio, omit J2 and run a wire directly from where the center
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connector of J2 is indicated to the car radio's antenna jack, otherwise
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use coax cable to connect from J2 to car radio antenna jack (see note 3).
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4) It is strongly suggested that you install the converter inside the
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chassis of the car radio (it simplifies the wiring and reduces noise). If
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you do not have room to do so, use a metal case for the converter and a
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SHORT length of shielded coax cable for the connection from the converter
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to the car radio's antenna jack.
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5) Connect +12 volt power input to car radio's on/off switch. That way you
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can turn both radio and converter on with that switch.
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6) When everything is working, tune in a shortwave station near the middle of
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the dial and adjust the slug of T1 for the strongest signal.
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7) You may use a signal generator or crystal oscillator to calibrate the
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dial, if desired.
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