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Chapter 2


Chapter 2:  K3 Configuration and Calibration


2.1    Introduction

This chapter describes the basic configuration and calibration settings needed to start operating the K3 and describes the operation of the K3 Utility program. Virtually everything you would normally set, switch, or adjust while operating is done with front panel buttons and knobs. You should only need to access the menus for changing the settings for various functions. 

There are three levels of menus. The MAIN menu, accessed by tapping MENU, adjusts things like VOX, transmit and receiver audio equalization menus, and LCD brightness. You may also choose between a Mic input at the front panel, a Mic at the rear panel, and the Line Input.

The Configuration (CONFIG) menus tell the K3 which options are installed, how they should function, allows fine adjustment of functions like AGC, and configures the RS232 port. You access the CONFIG menu with a hold (holding it longer than about ½ second) of the  MENU/CONFIG button. 

The Tech menu is simply an extension of the CONFIG menu, and allows access to some of the inner workings of the K3, like calibration and temperature monitoring. Access the Tech menu by setting TECH MODE On in the CONFIG menu. When you do, those additional Tech functions are added to the CONFIG menu choices.


2.2    Configuration Menus

. . .

2.2.1    Per-Mode, Per-Band, etc. Configuration

. . .


2.2.2    Programmable Function Keys

. . .



Program M1 to be a shortcut to the CONFIG:SPKR+PH menu.

· · · 

Hold MENU/CONFIG and tune VFO B to SPKR+PH. Tap M1 to store the shortcut and then tap MENU.



What happens when you tap M1 after programming it as a shortcut to the SPKR+PH menu?

· · · 

Each time you tap M1 SPKR+PH toggles between yES and no.


2.1    Downloading Firmware

2.3.1    The K3 Utility Program

. . .

2.3.2    Connecting Your Computer to the K3

. . .

2.3.3    Saving the K3's Configuration

. . .

2.3.4    Updating Firmware to the Latest Released Version

. . .

2.3.5    Updating Firmware to a Beta Version

. . .

2.3.6    Restoring an Older Version of the Firmware

. . .

2.3.7    Problems with Firmware Downloading

. . .

2.3.8    Keeping Firmware Update Records

. . .

2.4    Configuring the K3

2.4.1    Crystal Filter Setup

When installing the crystal filters in the Main and Sub receivers, instructions are given to install the widest filter in FL1 and progress successively to narrower filters in FL2, FL3, FL4 and finally the narrowest in FL5. Both the Main and the Sub receiver filters should be installed in this way. You may leave a filter slot open, say FL1, if you anticipate adding a wider filter, say for AM or FM, in the future. When the filters are installed, you must setup the K3 filters using either the CONFIG menu as described in the Owner's Manual or the K3 Utility program.



Figure 24.  Main crystal filters on RF board.


Figure 25.  Sub receiver crystal filters.


Using the K3 Utility Program to Setup the Crystal Filters

Although the K3 User's Manual describes how to setup the crystal filters, the K3 Utility program is far easier to use.

1.     Start the K3 Utility program as described above and make sure the communication link to the K3 is established.

2.     Click on the Configuration tab.

3.     Click on Save Configuration As … to save the current configuration so you can restore it if needed.

4.     Click on Configure Crystal Filters … .The display for the Main receiver (and transmitter) is shown in Figure 2‑6 and the Sub receiver in Figure 2‑7.

5.     Configure the bandwidth, frequency offset, and gain. In each of the Main and Sub receiver screens enter the Bandwidth of the filter installed in FL1 – FL5 and the Freq Offset given by Elecraft when you received the filters.

6.     You may want to enter some Gain (dB) to compensate for filter losses. Although it is tempting to set the gain so the audio level is equal across all filters, Elecraft recommends adding only 1 - 2 dB for 400-500 Hz filters and 3 - 4 dB for 200 – 250 Hz filters. The reason for this is that excessive gain can degrade the performance of the digital signal processing.

7.     Enable crystal filters for use in each of the modes. The check boxes shown in Figure 2‑6 and Figure 2‑7 specify the filter used in each of the modes. Although you might not use a 400 Hz filter for sideband, you should enable both the wider and narrower filters to use sideband mode for copying data.

8.       Enable transmit filters (only in the main screen, Figure 2‑6). Enable the 2.7 or 2.8 kHz filter for CW, LSB, USB and Data transmitting. Select a 6 kHz filter for AM and 13 kHz filter for FM transmissions if available. Although the menu will allow you to chose a narrower filter for CW transmission, you should not do this. If you do, the K3 will not transmit and you will receive the ERR TXF error message.

Offsets for Diversity Reception

If you have installed the KRX3 Sub receiver, you may wish to change the frequency offset of the filters in the Main and Sub receivers from the given offsets Elecraft specifies for the filters (step 5 above). Ideally, the crystal roofing filters in the Main and the Sub receivers should, in theory, be identical for diversity reception. In practice, if they are within 40 Hz or so, you will not detect any significant degradation in diversity reception. A compromise setting for the filters is to split the difference between the two offsets. For example, if a 2.7 kHz filter in the Main receiver is -0.87 and the 2.7 kHz filter in the Sub receiver is -0.85, you may set each to -0.86 as shown in Figure 2‑6 and Figure 2‑7.


Figure 26.  Main crystal configuration screen.



Figure 27.  Sub receiver crystal configuration screen.



The 2.7 kHz 5-pole filter offset in the Main receiver is -0.70 and in the Sub receiver is -0.76. What frequency offset will you enter to get the best performance for diversity reception?

 · · · 

Enter -0.73.


Advanced Crystal Configuration

A number of operators configure their filter bandwidth slightly differently. The bandwidth given in Figure 2‑6 and Figure 2‑7 is the DSP controlled bandwidth at which that roofing filter will be switched in. For example, let's say you are operating CW with the DSP filter WIDTH control set at 700 Hz. The 1.00 kHz roofing filter will be in use. If you now change the DSP WIDTH to 400 Hz, the 400 Hz filter will be automatically switched in. Because the 400 Hz filter has a -6 dB bandwidth of 435 Hz, you may prefer to set the filter bandwidth switching point to something higher than 400 Hz, perhaps 500 Hz.


Table 22.  Alternate filter bandwidth switching points.


Alternate Switching Point

250 Hz

400 Hz

400 Hz

500 Hz

1.8 kHz

2.1 kHz


2.5    Calibrating the K3

. . .

2.6    Other K3 Set Ups

2.6.1    Switch Feedback Tones

. . .

2.6.2    Setting the Time and Date

. . .

2.6.3    Visual and Audio Effects

. . .

2.6.4    Other Miscellaneous Configurations

. . .

2.7    Reset – When All Else Fails

The K3's configuration menu parameters are stored in non-volatile (EEPROM or Flash) memory. These parameters are retained when the power is turned off, hence the name non-volatile memory. Although rare, it is possible for the non-volatile memory to become corrupted resulting in the K3's firmware running incorrectly. If this happens, you should reinitialize all parameters to the factory default values and then reload your configuration. Here is a procedure for doing this.

What to do before a memory failure occurs

1.     If you have a computer with the K3 Utility program, save the current configuration as described in section 2.3.3. Although the K3 Utility program does not (at time this is written) have the ability to print out a hard copy of the configuration, the Ham Radio Deluxe program does.[1]

2.     If you do not have a computer, write down important menu parameters such as CONFIG:FLx BW and CONFIG:Lx FRQ for each filter in the Main and Sub receivers. In addition, record the K3 option module enables such as CONFIG:KAT3 etc.

Initializing parameters to the default setting

1.     Tap POWER to turn the K3 off (leave the power supply connected and turned on.)

2.     Hold in SHIFT/LO Æ knob and tap POWER to turn the K3 on. After about two seconds release SHIFT/LO Æ. You should now see EE INIT on the LCD.

3.     EE INIT should complete in a few seconds. If you see ERR PL1 or other error messages, tap DISP to clear each.

4.     If you have a computer, reload the configuration using the K3 Utility program as described in Section 2.3.3, unless, as Section 2.3.7 describes, the configuration file has become corrupted. Then, you should not reload the file. Instead, manually re-enter configuration menu items.

5.     If you do not have a computer, manually restore the configuration items you wrote down and then redo the calibration items shown in section 2.4.


2.8    K3 Microphone Set Up

There are two choices for a microphone connection. The front panel has an 8-pin connector as shown in Figure 2‑8 and Table 2‑7. There is also a rear panel MIC input, whose circuit is shown in Figure 2‑10. Table 2‑9 shows configuration menu items for setting up your microphone. See Chapter 3 for procedures for setting up your microphone gain, compression and VOX levels and Appendix A for a list of various microphones and their setup requirements.



Figure 28.  K3 microphone connector, viewed from the front panel.



Table 27.  K3 microphone front panel microphone connector.





Mic Audio

Low impedance, unbalanced input, works with balanced or unbalanced dynamic mics, but only an un-balanced electret condenser mic. +5 V supplied when FP.x bIAS is on.



Ground this input to push to talk.


DOWN Button

See CONFIG:MIC BTN to enable. The mic button should ground this connection when pressed.


UP Button

See CONFIG:MIC BTN to enable. The mic button should ground this connection when pressed.


Function Button

Not currently supported by the K3 firmware.


8 V Bias

Provides 8 V at 10 mA max for biasing unbalanced electret condenser microphones or powering a microphone preamp. See Appendix A for a list of each microphone type and requirements for bias.



Pin 7 and pin 8 are connected together.




Table 29.  Menu entries for the microphone input.

Menu Entry





You may select the front panel 8-pin MIC connector (FP), the rear panel 3.5 mm MIC jack (RP), or the rear panel LINE IN jack for your microphone.


Tapping  1  toggles between .Low and .High microphone gain range.


Tapping  2  turns microphone bIAS on and off. See Appendix A for a list of microphones needing bias to be turned on (electret and condenser mics). When on, +5 V is supplied to the MIC input, pin 1.


When you select FP, tapping  7  turns on or off a high-gain front panel microphone preamplifier. This is independent of the .Low and .High microphone gain range activated by tapping 1  and is useful if you have a low output mic element.



This control allows both the microphone and the Line In jack to be used for transmit audio. Both sources may be used when MIC+LIN is ON and MIC SEL is FP or RP. When this is the case, rotating MIC sets the microphone gain. When MIC SEL is set to LINE IN, the MIC+LIN selection is overridden and you may rotate MIC  to set the Line In gain.

Caution: You may choose to use MIC+LIN ON when operating in a contest and using the computer to send CQ and reports using wave files. When the computer connected to LINE IN is transmitting, your microphone is live and anything you say during this time will be transmitted.

This caution also applies when you are in DATA mode. It is best to set MIC+LIN to OFF to avoid microphone pickup of the transmitted tones and the resultant feedback situation.



When set to ON, a microphone with UP/DOWN buttons will tune the VFO up or down. Tapping the UP/DOWN button will move the VFO up or down one step. Holding UP/DOWN will move the VFO continuously. If the VFO moves continuously without holding the buttons, the microphone is not compatible with the K3 circuits and CONFIG:MIC BTN should be set to OFF.



Configure the Main menu to use a high-output Elecraft MH2 electret microphone needing bias using your K3's front panel MIC connector.

· · · 

Tap MENU and tune VFO B to MIC SEL. Select FP with VFO A, tap  1  to select FP.L and tap  2  to select FP.L bIAS.



Configure the Main menu to use a low-output Heil HC-4 dynamic microphone not needing bias using your K3's rear panel MIC connector.

· · · 

Tap MENU and tune VFO B to MIC SEL. Select RP with VFO A, tap  1  to select FP.H and tap  2  to select to remove FP.H bIAS.


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