ELECRAFT XG3 User manual

831-763-4211
ELECRAFT XG3
RF SIGNAL SOURCE
Owner’s Manual
E740154 Revision D3, July 26, 2017
Copyright © 2017, Elecraft; All Rights Reserved

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Table of Contents
Introduction.................................................................................................................................................4
Specifications..............................................................................................................................................5
Customer Service and Support....................................................................................................................6
Technical Assistance...............................................................................................................................6
Repair / Alignment Service.....................................................................................................................6
Battery Installation......................................................................................................................................7
External Power Supply ...............................................................................................................................7
Basic Operation...........................................................................................................................................8
Computer Controlled Operation..................................................................................................................8
Programmable Sweep Functions...............................................................................................................10
Programmable Morse and RTTY Sender..................................................................................................11
 .................................................................................................14
Reverse Power ..........................................................................................................................................14
Applications..............................................................................................................................................14
Receiver Testing ...................................................................................................................................15
Receiver Alignment ..............................................................................................................................17
RF Signal Tracing and Troubleshooting...............................................................................................17
VFO/LO for Experimentation...............................................................................................................17
Updating Firmware...................................................................................................................................18
XG3 Remote Control Commands.............................................................................................................18
Serial Port Settings................................................................................................................................18
Boot.......................................................................................................................................................18
Transmission Protocol ..........................................................................................................................18
Command Entry, Arguments and Device Limits..................................................................................19
Command Reference.............................................................................................................................20
Tech Mode Commands.........................................................................................................................25
Circuit Description....................................................................................................................................27
Serial Interface Cable Schematic ..............................................................................................................30
APPENDIX A JUMPERING THE FUSIBLE TRACE.........................................................................31
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Elecraft manuals with color images may be downloaded from www.elecraft.com.

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Introduction
The XG3 is a miniature RF signal source that provides output from 1.5 MHz through 1400 MHz. Four
commonly used selectable output levels are calibrated from 1.5 through 200 MHz.
The XG3 may be operated from its internal battery or from an external 11-14VDC source. It is housed in a
protective enclosure with easy-to-use front panel switches and LED indicators.
ckly checking the performance of equipment in the
field as well as at the home station (see Reverse Power on pg 14).
Never apply RF power or voltage to the XG3 RF OUT connector.
If you are working with a transmitter or transceiver, disable the transmitter (turn the power to minimum,
disconnect any microphone or key or, if available, put the transceiver in a test or standby mode so transmit
is disabled.) Transmitting into your XG3, even briefly, will damage it. Such damage is not covered under
the Elecraft warranty.
If connecting the XG3 to circuits where voltages are present, use a blocking capacitor to keep those
voltages from reaching the XG3. A fusible trace is provided that may protect the XG3 in the event you
accidentally apply voltage or RF power to the RF OUT connector. If that happens, you may be able to
restore operation by installing a jumper to bypass the trace as described in Appendix A on pg 30.
A computer interface permits selecting up to 12 preset frequencies that are stored so they are available
when the XG3 is used without the computer. In addition, two sweep frequency ranges may be chosen with
a selectable sweep step size a sweep rate as little as 1 ms. An interface cable for connecting the XG3 to
your computer is included. A USB interface cable is provided unless you specifically requested a RS232
interface cable be supplied instead. If you want both cables, you can purchase the second one from Elecraft:
Order KXUSB for the USB interface cable or order KXSER for the RS232 interface cable. Optionally you
can assemble your own RS232 interface cable. See Serial Interface Cable Schematic on page 30.
The XG3 is a versatile tool that may be used for receiver testing, receiver alignment, RF signal tracing and
troubleshooting and may even serve as a VFO or local oscillator or homebrew projects (see Applications on
pg 14).

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Specifications
Frequency Range:
1.5-200 MHz range, with a typical resolution of 1-24 Hz. (Up to 1400
MHz via harmonics)
Frequency Stability:
±50 ppm, maximum.
Signal Characteristics:
Highly stable RF square wave; phase noise -105 dBc/Hz
Reverse Power:
Shunt diodes and a fusible pc trace link provide limited protection. See
Reverse Power, pg 14.
Preset Frequencies:
12 frequencies preset at the factory - one in each Amateur band from 160
through 2 meters. Frequencies may be changed using a personal
computer (pg 8).
Sweep Mode:
Two frequency ranges preset. The sweep speed and the frequency
increment for each step may be programmed using a personal computer
(pg 8).
Computer Interface:
RS-232 or USB: Allows changing the preset frequencies and operating
the XG3 from a personal computer using the XG3 Utility program
available free from Elecraft. Note: For information on writing your own
XG3 control programs, see XG3 Remote Control Commands on pg 18.
Selectable Output Levels:
Four levels, calibrated from 1.5 through 200 MHz:
0 dBm (± 3 dB), -33 dBm, -73 dBm, - 107 dBm (± 1 dB typ).
Output Impedance:
50 ohms.
Power:
Internal 9-volt battery or external 11-14 VDC supply
Power Consumption:
External supply, 60 mA maximum at 0 dBm output. Less at lower output
levels.
Internal battery drain, up to 50 mA at 0dBm output, 25 mA typical at
lower output levels.
Programmable automatic power shutoff.
Frequency Resolution:
Limited by the internal PLL divisor precision. Typical values are as
follows:
1.5 to 66 MHz:
1 to 10 Hz.
67 to 159 MHz:
1 to 12 Hz.
160 to 200 MHz:
1 to 24 Hz

6
Customer Service and Support
Technical Assistance
You can send e-mail to [e-mail] and we will respond quickly - typically the same day
Monday through Friday. Telephone assistance is available from 9 A.M. to 5 P.M. Pacific time (weekdays
only) at 831-763-4211. Please use e-mail rather than calling when possible since this gives us a written
record of the details of your problem and allows us to handle a larger number of requests each day.
Repair / Alignment Service (We want to make sure everyone succeeds!)
If necessary, you may return your Elecraft product to us for repair or alignment. (Note: We offer unlimited
email and phone support to get your kit running, so please try that route first as we can usually help you
find the problem quickly.)
IMPORTANT: You must contact Elecraft before mailing your product to obtain authorization for the
return, what address to ship it to and current information on repair fees and turnaround times. (Frequently
we can determine the cause of your problem and save you the trouble of shipping it back to us.) Our repair
location is different from our factory location. We will give you the address to ship your kit to at the time
of repair authorization. Packages shipped without authorization will incur an additional shipping charge
for reshipment to our repair depot.
Elecraft's 1-Year Limited Warranty
This warranty is effective as of the date of first consumer purchase (or if shipped from factory, date product is
shipped to customer). It covers both our kits and fully assembled products. For kits, before requesting warranty
service, you should fully complete the assembly, carefully following all instructions in the manual.
Who is covered: This warranty covers the original owner of the Elecraft product as disclosed to Elecraft at the
time of order. Elecraft products transferred by the purchaser to a third party, either by sale, gift or other method,
who is not disclosed to Elecraft at the time of original order, are not covered by this warranty. If the Elecraft
product is being bought indirectly for a third party, the third party's name and address must be provided to Elecraft
at time of order to insure warranty coverage.
What is covered: During the first year after date of purchase, Elecraft will replace defective or missing parts free
of charge (post-paid). We will also correct any malfunction to kits or assembled units caused by defective parts and
materials. Purchaser pays inbound shipping to Elecraft for warranty repair, Elecraft will pay shipping to return the
repaired equipment to you by UPS ground service or equivalent to the continental USA and Canada. Alaska,
Hawaii and outside U.S. and Canada actual return shipping cost paid by owner.
What is not covered: This warranty does not cover correction of kit assembly errors. It also does not cover
misalignment; repair of damage caused by misuse, negligence, or builder modifications; or any performance
malfunctions involving non-Elecraft accessory equipment. The use of acid-core solder, water-soluble flux solder, or
any corrosive or conductive flux or solvent will void this warranty in its entirety. Also not covered is
reimbursement for loss of use, inconvenience, customer assembly or alignment time, or cost of unauthorized
service.
Limitation of incidental or consequential damages: This warranty does not extend to non-Elecraft equipment or
components used in conjunction with our products. Any such repair or replacement is the responsibility of the
customer. Elecraft will not be liable for any special, indirect, incidental or consequential damages, including but not
limited to any loss of business or profits.

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Battery Installation
The XG3 uses a single 9-volt battery (common ANSI/NEDA 1604 size). The battery compartment is on the
lower back. Slide the cover open by pushing it toward the bottom of the XG3. Align the battery so the
narrower (+) battery terminal is aligned with the narrower contact in the battery holder (Figure 1) and press
the battery down so the back is against the support shown.

the battery terminals are facing away from the contacts in the XG3.
Note the XG3 has reverse-polarity protection in the event you insert the battery incorrectly.
Figure 1. Installing Battery
External Power Supply
The XG3 may be powered by an external 11 to 14 VDC supply capable of supplying at least 60 mA. The
XGC power jack accepts a 2.1 mm coaxial connector: negative to the outer ring and positive to the inner
terminal (see Figure 2). The battery may be left in the XG3. No current drain from the battery occurs as
long as external power is applied.
Figure 2. External Power Connector

8
Basic Operation
CAUTION
When connecting the XG3 to the output of a transceiver or transmitter, be sure to prevent
accidentally keying the transmitter even for brief periods. The XG3 has protection against
low-level signals applied to the RF OUT connector, but transmitting into the XG3 even for
a brief period will destroy internal components. Such damage is not covered under the
Elecraft warranty (see Reverse Power on pg 14).
The XG3 may be operated as an independent, stand-alone RF signal generator using the four red switches
on the front. Tap (press briefly) the On/Off switch to turn the unit on. One of the Band LEDs and one of the
Level LEDs will light. To turn the XG3 off, hold (press for more than 1 second) the On/Off switch. To
conserve the battery, the XG3 will turn itself off after 10 minutes without any user input.
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Note: If you hold the On/Off switch down more than 10 seconds, the XG3 will go
0 dBm LED. To restore normal operation,
disconnect external power (if used), then remove and reinstall the battery.
Select the band desired using the Band + andswitches. The XG3 is pre-programmed with a test frequency
in each band as shown below. You can change these frequencies using a computer as described below
under Computer Controlled Operation.
BAND
FREQ (MHz)
BAND
FREQ (MHz)
BAND
FREQ (MHz)
160
1.820000
30
10.120000
12
24.900000
80
3.520000
20
14.020000
10
28.020000
60
5.330500
17
18.120000
6
50.120000
40
7.020000
15
21.020000
2
144.220000
The output signal level is shown by the LEDs next to the Level switch. Tap the switch to cycle through the
three lower output levels. The highest signal level, 0 dBm (1 milliwatt), is selected by holding the Level
switch for at least 1 second. An external power supply (pg 7) is recommended if you need to operate the
XG3 at the 0 dBm output level for an extended period of time.
Computer Controlled Operation
A personal computer will allow you to change the test frequencies and customize other parameters. The
XG3 may be operated from the computer interface or you may program your XG3 and then use it as a
stand-alone RF signal generator with the parameters you chose.
A serial cable is provided with your XG3. You will need:
A computer with an RS232 port or a USB port, depending upon whether you chose the RS232 or
USB interface cable when ordering your XG3. Optionally, you can use the RS232 interface cable
with an RS232 to USB adapter.

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The XG3 Utility program for your computer. It may be downloaded free from www.elecraft.com.
Launch the XG3 Utility Program:
A computer with an RS232 port or a USB port, depending upon which computer interface
cable you ordered with the XG3. See Introduction on page 4 for information about the
interface cables.
Launch the XG3 utility program and turn the XG3 on.
Click on the utility program PORT tab and select the active port. Confirm that the computer is
communicating with the XG3 by clicking on TEST COMMUNICATIONS. A pop-up window
should open reporting the XG3 firmware version if you have selected the correct serial port and
the cables are properly connected.
Operating and Programming Your XG3
Click on the utility program OPERATE tab. All of the frequencies shown on this page are in MHz
and the least significant digit shown is Hz.
The CURRENT FREQUENCY (MHz) shows the current frequency reported by the XG3.
To the right is STEP SIZEmoved if you
click the up and down arrows next to the CURRENT FREQUENCY window. You can edit this
value as desired.
You can change the frequency to any value from 1.500000 MHz to 1400.000000 MHz by entering
it in the CURRENT FREQUENCY window and then pressing Enter on your computer keyboard to
transfer the frequency data to the XG3. ter all the zeros, just the significant
places. The utility program fills in the remaining zeros when you leave that window.
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If the utility program stops allowing you to make changes, check the XG3. It
turns off automatically after a period of time (the default is 10 minutes) unless one
of its front panel switches has been pressed. If needed, simply turn the XG3 on
again to continue.
In the Frequency Memories area, clicking on the button next to a band will transfer the frequency
shown on the button to the XG3.
Click on Edit to change the frequency associated with each band. An Edit Memory Frequencies
window will open. Type in the desired frequency for each band. You can enter any frequency
between 1.500000 and 1400.00000 MHz for any band position. That is, you can assign
900.000000 MHz to the 80 meter band if you wish. The band wavelength numbers (e.g. 160, 80,
60, 40, etc.) are there to help you remember which frequency is associated with each position
when you use the XG3 without the computer.
Click on OK to accept the new frequencies you have assigned to the band locations. Click on Set
All to Factory Default to return them to the default frequencies.

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The Output Level radio buttons allow you to set the output level from the computer instead of
using the Level switch on the XG3. The Output Level selections are accurate only for frequencies
up to 200 MHz since higher frequencies rely on harmonics of the fundamental RF signal.
The Enable Output radio button allows you to turn the XG3 RF output off or on. When RF output
is disabled, the XG3 is otherwise fully operational and can be programmed.
You can adjust the time the XG3 will operate without a switch being pressed. The default is 10
minutes. Click on the CONFIGURATION tab, then on OTHER SETTINGS, enter the desired
Automatic Power Off time and press Enter to send the new value to the XG3. Do not change the
- set frequency calibration (see
pg 11).
Programmable Sweep Functions
Two programmable functions that sweep the signal across a range of frequencies are provided. Once
programmed, they can be initiated by holding the PF1 or PF2 switches on the XG3 or by clicking on the
Sweep 1 or Sweep 2 buttons on the XG3 utility OPERATE tab. When a sweep is in progress, one of the
band LEDs on the XG3 will blink. The blinking LED will be whichever one was selected last before the
sweep was initiated.
Program a sweep as follows:
With the XG3 connected to a personal computer (see Computer Controlled Operation above) and
the XG3 Utility program running, click on the OPERATE tab.
Click on Edit Sweeps to open the Edit Programmable Sweep Memories page.
Enter the Start Frequency and End Frequency. Note that the starting frequency must be lower than
the ending frequency. That is, the frequency always increases during a sweep.
Enter the Step Frequency. This is the amount the frequency will increment during each step in the
sweep.
Enter the desired Step Time (the time the signal remains at each step before continuing) in
milliseconds (1000 ms = 1 second).
If you want the sweep to repeat, check the Repeat box. The XG3 will sweep to the end frequency
and then return to the starting frequency and begin a new sweep.
Click on APPLY to send the data to the XG3 and leave the window open or OK to send the data to
the XG3 and close the window.
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NOTE: The XG3’s frequency steps occur rapidly, without a shaping
envelope. This allows very fast sweeps. However, each transition will
generate sidebands that will be audible in a receiver and visible on a
spectrum analyzer.