Elecraft KRC2 Manual User Manual

Elecraft • www.elecraft.com • 831-662-8345ELE CRAF T KRC2BA ND D EC OD ER a nd C ONTR OLLE RAssembly and Operating InstructionsFo

10Install 10k, 1/4 watt resistors (brn-blk-org) at R2 and R11 on the bottom side of the PCB.__R2, __R11Install the 40-pin IC socket at U1 on the bott

11Install the subminiature DPDT slide switch S5 on the bottom side of the PCB. Make sure theswitch is firmly seated against the board when soldering.

12Install J1, a female PC-mount DB9 connector on the bottom side of the PCB. This position isapproximately in the center at the end of the PCB. The co

13Adjacent to J1, on the bottom side of the board, you will find two pads connected by a whiteline. Using one of the 1N4007 diode leads previously sav

14Visual Inspection: Using a magnifying glass, examine the entire board for unsoldered pins,solder bridges, broken leads, or backward diodes or ICs. R

15KRC2 Test ProcedureThe KRC2 should be powered from its DC barrel jack using a +12 volt supply for its initialpower-up. No other connections should b

16KRC2 Final AssemblyPlace the case bottom onto the case top, aligning the screw holes at each end of the case. Thecase may be a tight fit, but the tw

17Figure 6Remove the female connector from the vise (K2 or K2/100 end), and insert the maleconnector (KRC2 end). Solder the wires to this connector us

18Using the KRC2The features described in this section are available with KRC2 firmware version 1.5 and later.Please see earlier revisions of this man

19Default Key BehaviorThere are four buttons on the top of the KRC2, labeled F1, F2, F3 and F4. In the KRC2's factoryconfiguration, the F1-F4 but

2Table of ContentsSpecifications...1Parts Inventory...

20KRC2 Jumper ConfigurationThere are 21 jumpers in the KRC2 allowing for a wide range of device options. The W1-8 block,located near the front of the

21Jumpers W4 and W5 determine the bandmap used for outputting band data. For normal use theyshould be removed. The KRC2 Configuration tool allows the

22When the KRC2 is set to receive band data in an analog mode, the jumpers associated with theselected input should be removed from the J2 connection.

23• K2 serial port used for band, data and control communications. Stand-alone (no PC):The KRC2ACC may use this setup for communications with the K2.

24Icom using analog band data. Here we use the radio’s analog band output for band information.Control and data transfers are not available. Some Icom

25KRC2 Power ConnectionsThe KRC2 may be powered from one of several sources. Themicrocontroller and logic are powered either from the K2 through theDB

26Using the KRC2 with non-Elecraft RadiosThe KRC2 is designed to accept band information from radios other than the K2. As discussed inKRC2 Jumper Con

27TroubleshootingIf you have any difficulty with your KRC2:Most problems in building the KRC2 are caused by poor or non-existent solder joints. Closel

28DC Voltage ChartVoltages are approximate and will vary up to +/- 10% due to normal component variation withoutaffecting the operation of the KRC2. M

29Circuit DetailsRefer to the schematic diagram, Figure 7 on page 29.U1 is a PCI 16F877A microcontroller. This device controls the operation of the KR

3Parts InventoryThe table below lists all parts in the kit. Typical markings on capacitors, as well as resistorand RF choke color codes, are shown in

30C1C2VoutVinGnd1 32U3 78L05C13C14+C12.1.1220 µFR31KC20.13333RxTxC16.01D71N4148D61N4148+C1510 µFS4S3S2S1F1F2F3F4D3 1N4007C9C11C8C6C10L2L3L18RR9 100.00

31/SRCLRSRCKSOUTVCCRCKSINGNDGNDGND/Q0/Q1/Q2/Q3/Q4/Q5/Q6/Q7/G1213191110141516171829834567U6/SRCLRSRCKSOUTVCCRCKSINGNDGNDGND/Q0/Q1/Q2/Q3/Q4/Q5/Q6/Q7/G12

32PCB LayoutThe corrected PCB layout is shown in Figure 10 for the top side and Figure 9 on page 31 for thebottom side.Figure 10 - KRC2 PCB corrected

33Figure 11 - KRC2 PCB corrected bottom view / silk screen parts placement.

34Customer Service InformationTechnical AssistanceIf you have difficulty with kit construction, operation, or troubleshooting, we’re here to help. You

4U1IC, programmed microcontroller, PIC16F877A-I/PE6100131U2IC, MAX1406 or LT1039E6000361U3IC, voltage regulator, 5V, 78L05E6000291U4, U5IC, UCN5891AE6

5Firmware RequirementsTo use the KRC2 with a K2 or K2/100 transceiver, you will need K2 main microcontrollerfirmware revision 2.01 or later and eithe

6On the top side of the board, install the 0.01 µF (103) capacitors with 0.1" (2.5 mm) leadspacing listed below, beginning with C28 in the upper

7Install the two 33pF ceramic disk capacitors on the top side of the PCB. Note that the leadspacing for C1 and C2 may be too wide for the holes in the

8Install the following resistors on the top side of the circuit board. Be sure to use the 4.7k 1/4watt resistor at R12. The smaller 1/8 watt resistor

9Note: The pin 1 end of ICs can be identified by a notch or dimple as shown in Figure 1. This endmust be oriented toward the notched end of the compon