The FSKit by Doug Hall, K4DSP


The FSKit - A simple sound card interface for RTTY Frequency Shift Keying

FSKit interface

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FSKit Parts Listing
Components Quanity Description Vendor Part Number
BOX 1 Bud enclosure: HP-3652-B Mouser 563-HP-3652-B
BT1 1 4.5 V dc dry battery holder (3 AAA) Mouser 12BH431P-GR
C1-C3 3 0.01 uF ceramic capacitor Mouser 81-RPER71103K2K1A03B
C4 1 0.1 uF ceramic capacitor Mouser 81-RPER71H104K2P1A03
J1, J2 2 3.5 mm stero phone jack Mouser 806-STX-3100-3NB
J3-J5 3 RCA phono jack Mouser 161-0360E
P1 1 Three pin header junk box  
P2, P3 2 Two pin header junk box  
Q1-Q3 3 2N7000 N-channel MOSFET Mouser 512-2N7000D74Z
R1, R5 2 10k ohm, 0.25 watt resistors Mouser 291-10K-RC
R2 1 50k ohm trimpot Mouser 652-3309W-1-503
R3 1 1M ohm, 0.25 watt resistor Mouser 291-1M-RC
R4 1 10M ohm, 0.25 watt resistor Mouser 291-10M-RC
T1 1 600 ohm 1:1 audio transformer Mouser 42TL016RC
U1 1 Atmel ATTiny45 microcontroller Mouser 556-ATTINY45-20PU
U2 1 TLC393 comparator Mouser 595-TLC393CP

Download files:

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Build Notes:

Operation Notes:

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  1. Doug Hall home page
  2. WinAVR -- Software development tools for the Atmel AVR microprocessors
  3. Firmware -- revision 1
  4. MMTTY by Makoto Mori, JE3HHT -- RTTY with Windows and Soundcard
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Revised: Tuesday, July 02, 2013 at 14:41:02 PM (EDT)