Elecraft KDSP2 Manual Manual de usuario

Elecraft • www.elecraft.com • 831-662-8345 ELECRAFT KDSP2 INTERNAL DSP FILTER and REAL-TIME CLOCK Assembly and Operating Instructio

10 You should have no low profile electrolytic capacitors remaining. Install the remaining electrolytic capacitors, starting near the upper left hand

11 The remaining TO-92 parts are NPN transistors. Q1 and Q3 are used in the auxbus interface, Q4 drives the LED and Q7 drives the audio muting circui

12 Near U3 is a small, cylindrical crystal. The exposed lead length should be about 0.1” (2.5 mm). Be careful with the crystal’s leads, as they are v

13 J1 20-pin female header (2 rows of 10 pins) J2 12-pin female header (1 row of 12 pins) When you install the IC in the next step, be very careful t

14 i NOTE: The short end of the pins on the male headers are soldered into the KDSP2 PCB. On the bottom of the PCB at the now-right hand side: P1 5

15 Control Board Preparation The control board of the K2 may need to be modified to accept the KDSP2. If you already have a KAF2, no further changes

16 Using solder wick or a desoldering pump, carefully clean out the holes of solder where the leads of R18 and R19 were. DO NOT overheat the pads. I

17 Use the supplied 4-40 x ¼” screw and the original lockwasher to secure the KDSP2 to the threaded spacer. Do not overtighten the screw - the spacer

18 Initial Checkout Set the K2 AF GAIN control to minimum. This is good practice whenever you turn on the K2 as there may be a loud “POP” in the aud

19 3-Volt Lithium Cell Installation Turn the K2 off. The (+) side of the 3-volt cell must be oriented towards the DSPx module. The (-) side must fa

2 Real-Time Clock The real-time clock displays 24-hour time, as well as date. You’ll find the clock convenient for field operation. Time can be eas

20 Final Assembly Before re-assembling your K2 or K2/100, you need to add the self-adhesive foam retainers. These will help protect the DSPx module

21 Attach the foam to the top cover. If you normally have the counter cable installed in your K2, re-install it now. When you re-install top cover as

22 Attach the foam to the heatsink. We recommend you not leave the frequency counter cable installed in your K2/100. When you re-install KPA100 asse

23 Operating the KDSP2 The KDSP2 is controlled by the K2’s DISPLAY, AFIL, BAND+, BAND-, RCL and STORE buttons. When a button is to be momentarily

24 Mode Filter Center Width Notch Denoise Denoise Level RTTY 1 LOW PASS LOW PASS Not avail Not avail Not avail 2 2.5 kHz 1000 Hz Not avai

25 To toggle the denoiser, tap the BAND+ button. S2 .n1 nt appears for a second. The “1” signifies the current noise reduction level. This displa

26 Note that the denoiser has been activated. It makes little sense to adjust the denoiser if you can’t hear the effect, so the KDSP2 automatically

27 If a CW or RTTY filter were being displayed, the numbers represent center frequency and width, like this: C.2 .60 .80 This shows standard CW filt

28 There is a special filter for each mode, called LPASS (for low pass). This filter widens out the passband so you can more easily eavesdrop on neig

29 dsp byP When the DSP is in bypass mode, if you invoke the DSP display (by tapping the DISPLAY button) you will always be sent to this menu s

3 Assembly Parts Inventory Please check the enclosed parts with this list. Check off each item in the space provided. The number following the che

30 Denoiser Menus nr 89 71 In this menu, the nr characters indicate the denoiser, or noise reduction, menu. The first number indicates the Beta, o

31 while the CW Denoiser menu looks like this: Cn G 0.0 The Filter Gain menus are prefixed: CF for CW Filter sf for SSB Filter rF

32 indicating the KDSP2 microcontroller firmware version. In this example, it is 3.00. If the MCU firmware is prior to version 3.00, you will be ret

33 Real-Time Clock Menus and Displays In addition to the DSP functions, the KDSP2 includes a real-time clock (RTC) function. The clock provides time

34 yr 03 Adjust the year by tapping BAND+ to increase or BAND- to decrease. The display will wrap around between 99 and 00. To adjust the mont

35 Menus Summary Mode Current Menu Next Menu CW Main Filter Filter Bypass Bypass Main SSB Main Filter Filter Bypass Bypass Main RTTY Fil

36 Mode Current Menu Next Menu DSP Time Calendar Format Calendar Format Year Year Month Month Date Date Hour Hour Minute Minute Time By

37 Table 1 from the beginning of this section is repeated here for the factory default filter settings. Mode Filter Center Width Notch Denoise Den

38 Troubleshooting General If your symptoms are not covered below, check the orientation of all components, connectors and wiring. Look especially

39 generator. Set the KDSP2 to 400 Hz center frequency and 300 Hz width. Turn up the AF GAIN until you hear filtered background noise. Now, increas

4 Capacitors OK Qty Reference Value Type Marking Part Number 1 C6 33 pF Ceramic Monolithic 33 or 330 E530144 1 C12 470 pF Ceramic Monolith

40 DC Voltage Chart Voltages are approximate. Measurements were made under the following conditions: 13.8 VDC power supply. K2 turned ON, 3V Lithium

41 Theory of Operation The DSP process flow is shown above. Incoming signals are digitized at a 16 kHz rate. The samples are then

42 Circuit Description The KDSP2 is an interface board that adapts the DSPx Module for internal operation in an Elecraft K2 Transceiver. Please

43 Auxbus Interface The K2 auxbus operates at a nominal 5V, but may be as high as 6V with some accessories. This is incompatible with the 5V microc

44 Real-Time Clock U3 is a real-time clock chip, incorporating clock and calendar functions. Y1 establishes the oscillator frequency of 32.768 kHz,

45 Glossary The KDSP2 introduces DSP technology to the Elecraft K2 transceiver line. There are many terms used that are not familiar to many Am

46 Coefficients In mathematics, the coefficients of an equation are usually constant values. For example, in the phrase Ax2 + Bx + C A, B and C ar

47 DSP Digital Signal Processing. This is a system that accepts signals that are digitized, and performs operations on them, such as filtering. In t

48 Length In DSP, filters consist of two blocks of memory. One holds the coefficients, and the other the sampled signals. The size of these two me

49

5 Integrated Circuits OK Qty Reference Value Marking Part Number 1 U1 ATmega8L ATMEGA8L E610015 1 U2 LM340T-5.0 LM340, 7805 E600024 1 U3 NJU6

50

6 You should pre-bend the leads of resistors close to the body and at right angles. Quarter-watt resistor locations on the PCB have 0.35” centers (9

7 R16 2.2K ohm ¼ watt 5% carbon film resistor (red-red-red-gold) R13 220 ohm ¼ watt 5% carbon film resistor (red-red-brown-gold) R14 1M ohm ¼ watt

8 Locate U2 and match it to the PCB. Pre-bend the leads to align with the holes in the PCB while keeping the mounting hole in U2’s tab in line with

9 Starting near the center left hand side of the PCB: C5 0.1 uF (104) C8 0.1 uF (104) C3 0.1 uF (104) C4 0.1 uF (104) Starting near the lower le