Construction Manual for the K2DI v.
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Page 3 INDEX Foreword ..................................................................... 3 K2DI v.III Digital Interface ............................................ 4 Picking the received AF signal up from P2 at the KAF2 or KDSP2 boards .............................................................. 9 K2DI-PCI Computer Interface....................................... 10 Pictures and Schematics .............................................. 15 How to install the separators ................................
Page 4 K2DI v.III Digital Interface Main features: • The circuit is the very same as the one used in v. II.2 but for an outlet of 5VDC that has been added to supply voltage to the K2DI-PCI. The board has been redrawn to a much smaller size: 59 mm (2 5/16") x 35 mm. (1 3/8").
Page 5 Cutting the Front Panel mike connector's AF and PTT lines and muting the AF amplifier, when transmitting data: Due to its low current drain and its switching features, I've chosen the use of a CD4053BE CMOS Analogue Multiplexer to cut and commute the AF and PTT lines from the Front Panel Microphone Connector, through J1, to the Rear Digital Connector when transmitting data, and to disconnect U2, the audio amplifier LM386, from the product detector by grounding the gates of Q1 and Q2, following Elecra
Page 6 K2DI v.III Parts List DESIGNATORS VALUE C1, C2, C3, C4, C10 C5 C8 C10 C6 C7, C9 J1 J1 and Microphone. Configuration Header at Front Panel board J2 J4 J5 at the RF board J4 & J5 at RF board J4 and J5 at RF board Q1, Q2 R4 R3 R1, R2 R5 R6 (*) R7 DESCRIPTION QTY 10µF 16/25v 220µF 16/25v .01 .022 .047 .1 Right angle dual row header IDC Female connector for flat cable.
Page 7 ASSEMBLY INSTRUCTIONS: Please note that all the soldering rules, warnings and tips you have learned and used when assembling your K2, are to be applied in the assembly of this circuit too. Install and solder components in the following order: a) _R1, _R2: 100K resistors (brown-black-yellow) b) _R3: 10K resistor (brown-black-orange) c) _R4: 2.7Ω resistor (red-violet-gold) d) _R5: 3.3 MOhm resistor (orange-orange-green) e) _R6: 2K trimmer pot (3329H202 or T7YB).
Page 8 (*) NOTES ON THE R7 RESISTOR'S VALUE TO CONTROL LM386's GAIN. The manufacturer's General Description of the LM386 reads: "…The gain is internally set to 20 to keep external part count low, but the addition of an external resistor and a capacitor between pins 1 and 8 will increase the gain to any value up to 200." The factory default gain of ±20, attained through the inner 1.35Kohm resistor allocated between pins 1 and 8 is too low for our needs.
Page 9 Picking the received AF signal up from P2 at the KAF2 or KDSP2 boards Caution: If you, to take advantage of the filtering provided by either circuitry of the KAF2 or KDSP2 devices and/or because the connection for the K2DI v III.2 is handier, decide to pick the received AF signal up from the P2 connection at the KAF2 or KDSP2 boards, instead of picking it up from the auxiliary AF connection provided at J5 on the RF board, please bear in mind the following facts: a.
Page 10 K2DI-PCI Computer Interface Main features: • The board measures 73 mm (2 7/8") x 35 mm (1 3/8"). • Its circuitry (see the schematics on page 29) features a Serial Port (RTS and DTR) PTT or a VOX (Tone) PTT, to be chosen by the user when setting the J3 and J4 jumpers in accordance with his/her needs and/or preferences. • The Serial Port is isolated by an optocoupler.
Page 11 In this way pin 1 will render a square wave signal whenever there is an AF signal fed to pin 2. In the absence of such an AF signal the output will be 0 (zero) volts. Because of this, whenever there is an AF signal fed to pin 2, the 1N4148 (D3) diode rectifies the square wave signal present at pin 1 and charges the C5 capacitor at 5 vDC. The values of the conjunct R7 and C5 determine the time constant, when the capacitor will remain charged.
Page 12 K2DI-PCI Parts List DESIGNATORS VALUE DESCRIPTION QTY C1 C5 C3, C4 C2 D1, D2, D3 J1 J1b J2 J2b J3 J4 LED1 P1 P2 Q1 R1, R3 R5 R2 R4, R7 R6 R8 TR1,TR2 U1 U2 J1b & J2b J3, J4 Separators .1µF .47µF 4.7µF 10µF 1N4148 Connector with locking tab Housing Connector with locking tab Housing Male header Male header LED Female Header Female Header PN2222A or MPS2222A 470 Ohm 10K 10K POT (Miniature) 100K 3.
Page 13 ASSEMBLY INSTRUCTIONS: Please note that all the soldering rules, warnings and tips you have learned and used when assembling your K2, are to be applied in the assembly of this circuit too.
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Page 15 Pictures Construction Manual for the K2DI v.
Page 16 K2DI v.III XRay image K2DI V.III Parts Placement Construction Manual for the K2DI v.
Page 17 K2DI V.III Constructed and ready to be installed K2DI v.III installed on the top cover of the K2 Construction Manual for the K2DI v.
Page 18 K2DI-PCI PCB’s x-ray image K2DI-PCI Parts Placement Construction Manual for the K2DI v.
Page 19 Constructed K2DI-PCI ready to be installed K2DI-PCI fitted on top of its motherboard, the K2DI v.III Construction Manual for the K2DI v.
Page 20 Side view of the installed PCBs KF2 with modified 3 pin male header Construction Manual for the K2DI v.
Page 21 KDSP2 Board. Mind the 2 pin header on the top K2DI-PCI board showing the female headers placed on the bottom Construction Manual for the K2DI v.
Page 22 Ribbon cable connected to the Front Panel Mic Configuration Header Side view of the K2, showing the ribbon cable coming out between the Control and Front Panel boards, the KDSP2 option and the installed K2DI v.III & K2DI-PCI boards. Mind the J1 and J2 straight connectors at the K2DI-PCI board. Right angled connectors collided with the Side Panel. Construction Manual for the K2DI v.
Page 23 The ribbon cable connected to the K2DI v.III Digital Interface How the Serial PTT and Soundcard cables are fixed to the top cover Construction Manual for the K2DI v.
Page 24 I have used a Minijack stereo for the Serial PTT rear connection and have isolated the PC signal GND with one bakelite washer. The jack is centered in the former OUT XVTR hole. Construction Manual for the K2DI v.
Page 25 How to install the separators The separators as well as the screws and nuts I provide are Metric 3 and because of that and for esthetic consistency sake, I suggest that, when installing the board(s) on the top cover of the K2, the constructor uses them instead of using the hardware supplied by Elecraft (screws and bolts for the loudspeaker and malefemale separators for the KBT2) KBT2 Internal battery setup Substitute the screws, bolts and KBT2 Battery Bracket’s separators for the ones supplied wit
Page 26 NO Internal battery setup Construction Manual for the K2DI v.
Page 27 Construction Manual for the K2DI v.
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Page 29 SCHEMATICS Construction Manual for the K2DI v.
Page 30 K2DI v. III K2 Digital Interface featuring a Mic. Configuration Header Extender and Rear Panel Data Connector (It Includes a buffered, fixed audio output and the cutting of Front Panel mic. connector's AF and PTT lines, when transmitting data). © Paulí Núñez, EA3BLQ - November 2003 J3 to MiniDIN conn.
Page 31 K2DI-PCI Sound card interface for the K2's K2DI by EA3BLQ Circuit for a daughter PC board of the K2DI v.III PCB, designed to interface the K2's DI with a computer. It features Opto isolation for the RS232 PTT circuit, as well as isolation for the sound card connections. Another remarkable feature is the possibility to choose the PTT mode between RS232 or VOX, according to user preferences.
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