- Select *WSPR* from the *Mode* menu.  The main window will
reconfigure itself to the WSPR interface, removing some controls not
used in WSPR mode.

- Set the Wide Graph controls as suggested below.

image::WSPR_WideGraphControls.png[align="center",alt="WSPR_WideGraphControls"]

- Use the mouse to drag the width and height of the main window to the
desired size.

- Select an active WSPR frequency (for example, 10.1387 or 14.0956 MHz).

- Click *Monitor* to start a WSPR receiving period.

- If you will be transmitting as well as receiving, select a suitable
value for *Tx Pct* (average percentage of 2-minute sequences devoted to
transmitting) and activate the *Enable Tx* button.

- Select your Tx power (in dBm) from the drop-down list.

=== Band Hopping
WSPR mode allows those with CAT-controlled radios to investigate
propagation on many bands without user intervention.  Coordinated
hopping enables a sizable group of stations around the world to move
together from band to band, thereby maximizing the chances of
identifying open propagation paths.

- To enable automatic band hopping, check the *Band Hopping* box on
the main window.

- Click *Schedule* to open the *WSPR Band Hopping* window, and select
the bands you wish to use at each time of day.

image::band_hopping.png[align="center",alt="Band Hopping"]

- Band-switching occurs after each 2-minute interval.  Preferred bands
are identified with time slots in a repeating 20-minute cycle,
according to the following table:

[width="80%",align="center",cols=">20,10*>8",options="header"]
|===
|Band:            |160|80|60|40|30|20|17|15|12|10
.3+|*UTC minute:* | 00|02|04|06|08|10|12|14|16|18
                 >| 20|22|24|26|28|30|32|34|36|38
                 >| 40|42|44|46|48|50|52|54|56|58
|===

- If the preferred band is not active according to your band-hopping
schedule, a band will be selected at random from among the active
bands.

- If the box labeled *Tune* is checked for a particular band, _WSJT-X_
transmits an unmodulated carrier for several seconds just after
switching to that band and before the normal Rx or Tx period
starts. This feature can be used to activate an automatic antenna
tuner (ATU) to tune a multi-band antenna to the newly selected band.

- Depending on your station and antenna setup, band changes might
require other switching besides retuning your radio. To make this
possible in an automated way, whenever _WSJT-X_ executes a successful
band-change command to a CAT-controlled radio, it looks for a file
named +user_hardware.bat+, +user_hardware.cmd+, +user_hardware.exe+,
or +user_hardware+ in the working directory. If one of these is found,
_WSJT-X_ tries to execute the command

 user_hardware nnn 

- In the above command +nnn+ is the band-designation wavelength in
meters. You must write your own program, script, or batch file to do
the necessary switching at your station.

The following screen shot is an example of WSPR operation with
band hopping enabled:

image::WSPR_2.png[align="center",alt="WSPR_2"]

A careful look at the screen shot above illustrates some of the
impressive capabilities of the WSPR decoder.  For example, look at the
decodes at UTC 0152, 0154, and 0156 along with the corresponding
minutes from the waterfall display below.  Yellow ovals have been
added to highlight two isolated signals decoded at -28 and -29 dB in
the first and third two-minute interval.  At 0154 UTC signals from
VE3FAL, AB4QS, and K5CZD fall within a 5 Hz interval near audio
frequency 1492 Hz; similarly, K3FEF, DL2XL/P, and LZ1UBO fall within
a 6 Hz interval near 1543 Hz.  Each of the overlapping signals is
decoded flawlessly.

image::WSPR_1a.png[align="center",alt="WSPR_1a"]
