Setting WSPR Power


Various Notes About WSPR Frequencies

Minimum WSPR Power.
I see remarks on WSPRnet Chat or Forum that users claim their rig power will not go below 5 watts.
With all transmitters when using SSB the RF power out is a reflection of the level of audio that is applied to the input, the microphone or data port.
The power control of a radio when on SSB/Data modes limits the maximum power, not the minimum. All it does is apply ALC if the audio input exceeds a certain level. It is often advisable NOT to drive a transmitter into ALC with digital modes.
Many say they cannot measure power below 5 watts so do not try. There is a method where low powers may be set with fair accuracy.

Reduce Audio Level.
There are several ways to reduce the input to a transmitter.
With Windows select the soundcard playback properties of the card selected in your WSPR setup.

Right click the speaker icon on the taskbar. Click "Playback devices". Select your soundcard, go the the "Levels" tab. Here the "Speaker" slider controls the audio to your transmitter.
 If you see another like this the "Line-in/Mic-In" must be muted. Click the speaker icon on that tab.

Right clicking on the slider on the "Level" tab enables you to choose dB readings. BUT I have found these dB scales may be very inaccurate, actually useless!
While you have this open make sure all special effects are disabled. On this soundcard the "Sound Blaster" tab has a box that needs to be ticked to disable them. Explore these tabs, maybe other buttons lead to other effects that need to be disabled. Enhancements may sound good through speakers but will not help WSPR!

WSPR itself has a digital output control.
Shown version 1.6.0 Hover your mouse cursor over the "Pwr" slider and the level is shown in dBs. Use your mouse wheel for easy adjustment. Earlier versions had the control at "Setup - Advanced"
"Transmit digital gain" may be reduced by up to 45dB. The mouse wheel will move the slider one step. Unfortunately it is necessary to move the cursor off, then on again to see the value. It is not possible to get exact dB values with steps of -0.3dB. Ignore the decimal point 1dB will make 1dB difference in SNR so a few tenths of a dB do not matter.

Steps I see:-0dB, -0.3, 0.6 0.9 1.2 1.5 1.8 2.1 2.4 2.7 3.0 3.6 3.9 4.2 4.5 4.8 5.1 5.4 5.7 6.0 6.3 6.6 6.9 7.2 7.5 7.8 8.1 8.4 8.7 9.0 and this seems to continue, -0.3dB steps so each 3rd dB is even.

To set audio levels so these controls will set the power.

If, for example you do not feel your power meter will read accurately below 5 watts then set your power control to about 10 watts. Then adjust either or both of the sliders shown above so that 5 watts is indicated. Now your power is controlled by the audio and power sliders. You may have to reduce levels significantly.  Note the dB readings on these sliders.

You now have the ability to reduce power by a known number of dB by using the WSPR Pwr control.

The box that shows the power value transmitted by your WSPR signal also shows dBm. 37dBm is the same as 5 watts.
So if you make the dB figure 7dB more negative on this or the audio control slider then you will be transmitting 7dBm less, 30dBm, 1 watt.
Then maybe reduce by a further 10dB. 37dBm -17dB is 20dBm, 100mW.
If your first step of setting 5 watts output is accurate then these powers will also be accurate.

Many SWR meters may be used to show lower powers more accurately. A meter that has a scale on it's reflected power display may be carefully used connected in reverse.
The reflected power meter will then read forward power.
Be careful, make sure your power control is at minimum and that you do not allow high power to be transmitted while you are testing.

Microphone Inputs.
Feeding audio from a computer into a microphone input is not ideal.A soundcard output is far too high to feed a microphone input directly. If the radio has a data input then use that.
To use a microphone input an attenuator will be required, just reducing the microphone gain is unlikely to be sufficient, If you manage to reduce the output power enough there may still be distortion and noise on your transmitted signal.

A suggested circuit, maybe one potentiometer may be enough but two give finer control. Almost any may be used, preset trimmers are small and convenient.

Using a 100 watt transceiver like this is not ideal, think about using a low power rig or maybe a home made transmitter, A Softrock or QRP Labs "U3S" is good. Others perhaps a little more complex are available maybe using the Raspberry Pi or Red Pitaya.

Another way to help reduce power is by using an attenuator in the antenna feed.
A 10dB attenuator will not affect reception, just about any commercial radio is sensitive enough. Note this attenuator must be built to be able to comfortably deal with at least 5 watts input.
A 100 watt transmitter will have a relatively high amount of  broadband noise present on the output. An attenuator will have the effect of reducing the amount sent to the antenna.
Commercial attenuators are available. This page has an Excel calculator for building yourself.

If you use a SDR at the bottom of this page I describe a way to control and display your WSJT-X power output in HDSDR.

60 metre WSPR Frequencies
April 2017 60m WSPR Frequencies.
There are two main Dial Frequencies in use, the original 5.287200MHz and the new 5.364700MHz.
5.364700MHz is within the recently agreed IARU segment and is used for transmitting by most European countries that have an allocation. It seems likely to eventually become available to many other countries.
5.287200MHz is used for transmit by countries that have not yet been allocated the new IARU frequencies, South Africa is the most commonly active on this frequency. (Sometimes you see other countries transmitting but often it is not actually legal for them.)
Although the UK has not yet been allocated the IARU frequencies 5.364700MHz does fall within one of our band segments. Some use the old frequency, some the new and some both.
[[VE7BPB is trying to establish Dial 5.355700 as the Canadian/N. American frequency. December 2017 nothing heard about this recently]]

December 2017. 80m WSPR The default frequency in WSJT-X v1.8.0 is now Dial 3.568600 (TX 3.5600-3.5800) to be within the Japanese allocation.
WSJT-X v1.8.0 has no default 60m frequency. I suggest that international listeners use Dial 5.364700MHz to spot Europe, this may encourage making 5.364700MHz a universal frequency.

Change WSPR Frequencies
To change frequencies in WSPR.
WSJT-X:- File - Settings (F2) Frequencies Tab:- Right click in the frequency list window - Insert. Select WSPR in the drop-down, type the frequency in MHz 5.364700 for example. - OK. (Do not select "Delete" unless you want the frequency you have selected to be deleted. If you do by mistake click "Cancel".
Both frequencies could be used simultaneously by using two WSPR profiles and two rigs/antennas.

Earlier versions of WSPR:- Type in the Dial Frequency in that box. Double click on the waterfall to set the TX frequency. This will be saved when you close WSPR. You may save two frequencies by using "Other" in the "Band" drop-down menu.

WSJT_X Profiles
To Start Different Instances (Profiles.)
Each instance may be setup completely differently. Or, as for 30m the same RX may be used for WSPR and JT9 monitoring. Set 2 instances, one for WSPR, one JT9 both with the same soundcard.
Each will have a different folder in \Users\...\AppData\Local\WSJT.... containing the ALL_WSPR.TXT or other data for that instance.

Probably the easiest way is to copy the shortcut on the Desktop. (Hold "Ctrl" drag shortcut to free area.) Rename it to match rig or, as I have usage. Then edit "Properties" (Right click.)
My one here renamed WSPR2, --rig-name=WSPR2 added after wsjtx.exe. - Apply

Profile shown in WSJT-X Title Bar (--rig-name=FT840)

You may also go to the \bin location shown below then create and rename a Shortcut.

[Also note "Shortcut key" in Properties above. Enter a keyboard character in that box and in the above example Ctrl-Alt-5 (or Alt_Gr-5) will open WSPR2]
Method shown in WSJT-X Help.   Main Page  For v1.7.0 Help see Section 14 and 15. Presumably the main WSJT-X page will link to any later versions.
Open a new text file in the WSJT bin folder found here on my setup C:\WSJT\wsjtx\bin wsjtx.exe will be here. Write the command, like this wsjtx --rig-name=WSPR Save, Rename  to a batch file for example WSPR.bat Then make a shortcut to it, (right click). Rename shortcut to match rig or as I have, usage.
Make as many differently named ones as you need.

I guess if when installing WSJT-X you had ticked the box "Include WSJT in the Path" then the .bat file could be on the Desktop or somewhere else, Windows would know where to go.
(Or if you put the full path in the .bat file, for example "C:\WSJT\wsjtx\bin\wsjtx.exe --rig-name=WSPR")

Playing with Fiq, BFO and Dial frequencies in older WSPR versions.

Change BFO so audio frequencies other than 1400-1600Hz may be used:- For RX only, with limitations.
WSPR 2.11_r2247 in non-IQ mode:- 600-800Hz audio.
Setup - Advanced BFO 700
Dial standard -800Hz
Then RX frequency listed in it's RX window is correct, and that saved in ALL_WSPR.TXT. But the waterfall scale is not. It does not upload spots.
This does not seem to work for TX, the TX frequency display is 1500Hz above the modified dial frequency. (Not tested this time.)

Change BFO in IQ mode.
WSPR 2.11_r2263 in IQ mode.
Setup - Advanced BFO 700.
Setup - IQ mode Fiq 12800 (Or reset LO frequency.)
Dial standard -800Hz
Then RX frequency listed is correct. But the waterfall scale is not. It does not upload spots.
This does not seem to work for TX, the TX frequency display is 1500Hz above the modified dial frequency. (Not tested)

So WSPR used this way will need manual uploads (or possibly an alternative script) and will give abnormally high SNR reports when used with narrow filters.

These older versions of WSPR do not run on my Windows 10 device. They did but stopped working after some update. The current WSJT-X includes WSPR but only for an ordinary mono 1400-1600Hz audio input, the BFO setting is not available. this page shows Fiq adjustments.

WSPR, a note regarding use with non-standard Dial Frequencies. For the non IQ mode.
Stewart ZS6SGM uses a commercial transceiver with only 500Hz steps. We discovered that WSPR may be configured to use non-standard Dial Frequencies.
For 60m the closest transceiver frequency to the standard Dial frequency of 5.2872MHz is 5.2870MHz.
Set WSPR "Dial" to the actual frequency. 5.2870.
Set "TX" to the actual frequency you require (5.2886-5.2888MHz) WSPR will actually transmit on this frequency.
The dial is 200Hz lower than standard. Set RX BFO in WSPR to 1700Hz. WSPR will then report the correct frequency of stations spotted. The scale in WSPR will be incorrect showing 200Hz lower but this is a visual defect. Another problem is that you will report your dial frequency to the "Activity" page if nobody is spotting your signal.

And WSPR will not upload spots. Use the Old Database page. Or this may be done with a batch file. Look here The main line requires changing, my example:-
"C:\MoreProgramFiles\WSPR\curl.exe" -F allmept=@"C:\MoreProgramFiles\WSPR\ALL_WSPR.TXT" -F call=G4ZFQ -F grid=IO90IR   This could be executed manually or with a utility, I use Pycron but probably Task Scheduler could be used.

A way to shift audio frequency digitally.

WSPR, Upload Batch File

"D:\MoreProgramFiles\WSPR-Folder\curl.exe" -F allmept=@"D:\MoreProgramFiles\WSPR3-Folder\ALL_WSPR.TXT" -F call=G4ZFQ -F grid=IO90IR
ping -n 200 >nul
goto A

rem For this to work get curl.exe from  put it in your WSPR working folder.
rem Modify the 4th line above by editing the paths (in "inverted commas") so it is your WSPR folder. And change to your call and locator.
Rem Then double clicking this .bat file should upload your ALL_WSPR.TXT
rem You could place this bat file in a convenient place or make a shortcut to it.

rem You could place curl.exe in it's own folder, then the start of line 4 would be different, perhaps "C:\Curl\curl.exe"
rem This bat is just my updated version of the one on the WSPRnet site.

"DT" value
DT is displayed in the WSPR receive window. This gives some measure of the timing. You will be using a method of keeping your computer on time, something like rsntp (You must right click the shortcut and "Run as Administrator". This one allows you to offset timing for testing). As an example a positive DT value means that your computer has measured that the start of a transmission was late. The DT value is not necessarily precise, several instances of WSPR on the same computer can give different DT values to the same signal. Note WSJT WSPR will still decode a signal about 4 seconds off.