WavViewDX User Manual

WavViewDX - Import


Supported Formats:

Here is a list of I/Q formats known to work:
- ELAD FDM-SW2
- Generic RAW recordings (plain data without header, see below)
- GQRX recordings
(see note below)
- HDSDR (all formats)
- Jaguar
- Linrad RAW, single and dual-channel recodings
- Perseus SDR (*.wav)
- Perseus P22 (*.p22)
- SDR# (see note below)
- SDR Console (all formats)
- SDR Uno
- SDRconnect (see note below)
- SpectraVue
- WiNRADIO DDC format (see note below)
- WiNRADIO RXW (only for G33)
- Winrad

If your SDR format is not supported, please contact me!


A
ttention SDR# users: Some of the needed data (sampling rate, time and date) is not stored in the file and has to be extracted from the file name, and path. As the time in the file name is not UTC, WavViewDX may show a wrong time, if the recording was made in a different time zone than local time zone, or if daylight savings time settings changed since the recording was made. It is recommended to keep the SDR# recordings in their original folder structure and the file name must not be changed. (E.g. "...\IQ\2025_01_27\06-04-43_1090000Hz.wav").

Attention SDRconnect users: Some of the needed data (sampling rate, time and date) is not stored in the file and has to be extracted from the file name. The file name should not be changed from its original name (e.g.
"SDRconnect_IQ_20250115_142500_875000HZ.wav"). It is fine to add text at the end of the file name, if the text starts with an underscore (e.g.
"SDRconnect_IQ_20250115_142500_875000HZ_your_text_here.wav")

Attention GQRX users: Some of the needed data (sampling rate, center frequency, time and date) is not stored in the file and has to be extracted from the file name. The file name should not be changed from its original name (e.g.
"gqrx_20250115_142500_1000000_2000000_fc.wav"). It is fine to add text at the end of the file name, if the text starts with an underscore (e.g. "gqrx_20250115_142500_1000000_2000000_your_text_here.wav")

Attention WiNRADIO users: If files are stored in DDC format. Make sure that "Insert FDT" is enabled, WavViewDX needs this information for a proper import. The file name should not be changed from its original name. The RXW format has no restrictions regarding the file name.

WavViewDX supports importing plain RAW data. Plain RAW data files only contain I/Q data. The file name must be in this format:
    iq_<dataformat>_ch<num_channels>_cf<center_freq>_sr<sampling_rate>[_dt<datetime>].raw
    <dataformat>: pcms8 | pcmu8 | pcm16 | pcm24 | pcm32 | float | double
    <num_channels>: 1 | 2
    <center_freq>: center frequency in Hz
    <sampling_rate>: sampling rate in hz
    <datetime>: start time of recording in the format YYYYMMDD-HHMMSS (optional)

Examples:
    iq_float_ch1_cf1000000_sr1560000.raw
    iq_float_ch2_cf1000000_sr2000000_dt20250316-195900.raw

Import Window:

The import window is used to import and analyze SDR recordings with WavView DX.



Source:
Enter path to the SDR recording. The path can either be a single file, or a folder (in case the SDR software split up the recording into multiple files, like the Perseus SDR software).
Click on the "Select" button to navigate through disks and folders. Click on buttons "Select File" or "Select Folder", whatever is appropriate.

RX QTH:
Select the RX / Antenna QTH, at which this recording was made. The location name will be displayed in the analysis picture, and this will be the pre-set QTH for log entries made from this recording. See QTH Manager for more details.

Advanced  Settings:
Special import settings / tewaks
- SDR#: Choose between local time (default) or UTC time in file name (if manually changed, SDR# uses local time)

Select Analysis Method:
Select the desired analysis method. Currently supported are:
- MW 10kHz Channel Analysis: Generate an
an analysis for the medium wave 10 kHz channels (for North and South America DX)
- MW 9+10kHz Channel Analysis: Generate an an analysis for the medium wave 10 kHz channels as well as for 9kHz channels
- MW 9kHz Fast Channel Analysis: Generate an an analysis for the medium wave 9 kHz channels (somewhat faster than the MW Full Channel Analysis, experimental)
- SW 5kHz Channel Analysis: Generate an analysis for short wave bands with 5kHz channels
- FM Band 100kHz Channel Analysis: Generate an analysis for the FM broadcast band with 100kHz channels


Select Analysis Method - Configure Buttons:
- Each analysis method has its individual configuration. See below for more information.

Import SDR recording:
Click here to start import and analysis. The analysis wiill be opened automatically when the import is complete.


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Analysis Configuration Windows:

The import configuration window offer verious settings. The settings may differ depending on the selected analysis, below is the collection of settings for all analysis types:



Video Resolution:
Select the time span that will be represented by one line (pixel). Default: 7.5s

FFT samples per minute:
More samples product a higher analysis quality, but also take more time. Default: 120 samples per minute.

Default contrast:
The contrast defines how SNR value will be represented in the analysis:
- Signals with SNR lower than dB min will not be shown in the analysis.

- Signals with SNR between dB min and dB highlight will be shown in gray/white color in ascending strength.
- Signals with SNR from dB highlight until db max will be shown in green color in ascending strength.
- Signals with SNR from dB highlight and stronger will be shown in green color and maximum strength.

The default contrast for the 10kHz analysis is 4/18/24 dB

The default contrast for the 9kHz analysis is 4/18/24 dB

Hidden Channels:
A list of all frequencies in kHz that will be hidden (shown in dark orange) in the analysis.

Included off-channel stations:
WavViewDX works with 50 Hz FFT slots, so carriers that deviate more than +/-25 Hz from the standard frequency will not be displayed by default. Add off-channels frequencies to this list to make them visible, the input format is in kHz floating-point (e.g. 1500.160).

SDR Sampling rate offset compensation:

Many SDRs have a sampling rate that deviates from the norm frequency. Use the compensation feature in order to make exact carrier frequency measurements.

- OFF: no compensation
  Use this setting if the SDR is linked to an stable reference (e.g. from GPS).
  If the SDR does not have a stable reference, better use one of the other settings.

- One reference carrier:
  Two values are needed, the reference frequency and the SDR clock deviation set in the recording SDR software.
  It is recommended to disable calibration in the recording SDR software, as this makes the setup easier.
  If
calibration in the recording SDR software is disabled, the value for SDR clock deviation is "1.0".

- Two reference carriers:
  Enter the reference carrier frequencies in Hz.

  Frequencies known to be undisturbed (at least around Munich) for the Leo Bodnar GPSDO are 466000 Hz and 1766400 Hz

  Expected accuracy in this more (if dual-channel GPSDO is used): less than +/- 0.02 Hz.

- Passive:
  WavViewDX estimates the compensation using carriers on 9 kHz slots.
 
Expected accuracy in this mode: less than +/- 2 Hz.

- By SDR Hardware:
  Select if the SDR in use has a built-in calibration feature (usually GPS-locked). Doing so will unlock storing frequency offsets in the log database.



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Using two reference signals

If your SDR does not have a reference clock input, which is fed with a GPDSO, then using two GPSDO generated reference signals, or two reference carriers is the most accurate solution.

Find two unused frequencies, one below the MW band and one above MW band. 466.000 kHz and 1766.400 kHz are known to work very reliable.



Alternatively you can use carriers of two broadcast stations, if those stations will deliver the strongest signals on their respective channels through the whole recording time.
There is a feature to check if your reference signals were working reliably.


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Using one reference carrier calibration (no offset compensation by recording SDR software)

If working with one reference carrier, it is recommended to make recordings without offset compensation.
- Perseus SDR: Make sure "Cal" is OFF.
- Jaguar seems to make no
offset compensation for recordings, so please follow these instructions for recordings made with Jaguar.

Set values:
Reference Carrier (Hz): Set frequency (in Hz) of your reference signal. If you don't have a GPS reference, you can also use a stable MW station, which is guaranteed to have the strongest signal on the channel all day.
TalkSport on 1089.000 kHz seems to be a reliable reference in many areas of Europe.
There is a feature to check if your reference signals were working reliably.

SDR Clock Deviation: Set to "1.0"

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Using one reference carrier calibration (with offset compensation by recording SDR software)

At least the Perseus SDR software does an offset compensation for recordings, then "Cal" is on. Currently there is no information available for other SDR software.
See here how to check if your recording SDR software uses a center frequency offset to compensate the SDR clock deviation.

Set values:
Reference Carrier (Hz): Set frequency (in Hz) of your reference signal.

SDR Clock Deviation: You have to look up this value in the SDR software used to make the recording. See below how this is done for Perseus SDR.

A recording made with offset compensation can deliver better analysis results than one without, especially for the higher frequencies of the MW band.
But as this value is no stored in the I/Q files, you have to remember the clock deviation for each recording, or make sure that the setting never changes.
So handling this is much more uncomfortable.

Make your life better by using
- either a SDR with reference clock input
- or a dual-channel GPSDO

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Is my SDR software recording with offset compensation?

There is a rather simple check available. First load the analysis of interest. In the menu, click on "More" -> "SDR Sampling Rate Offset Compensation".
In this window, click on "WavViewDX built-in passive compensation.

If the shown value for "Offset abs" is close to zero (less than 1 or 2 Hz), the recording is made without compensation.
The recording in the picture shown below was made without compensation. Use these instructions.
This recording was made without compensation


If the value for
"Offset abs" is not zero (usually larger than "Offset lin", but opposite sign), the recording is made with compensation, like in the following picture.
This recording was made without compensation
In this case, use these instructions, or disable offset compensation in the recording SDR software.


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Are my reference signals good?

Find out using the SDR sampling rate offset analysis. In the menu, click on "More" -> "Generate SDR sampling rate offset analysis". Here's an example that uses TalkSport on 1089 kHz. You see a big drift during the first hour of the recording, which is caused by the SDR warmup. The SNR of the carrier on 1089 kHz ir always above 15 dB and the calculated Offsets (abs and lin) are fairly stable. If you get a similar result, your reference source is good and the offset mesaurement will be very exact.The red dots mean that WavViewDX applied an error correction, as long as the first two columns are as smooth as in this example, there is absolutely no problem.





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Using one reference carrier calibration with the Perseus SDR Software

The calibration with one reference carrier needs to know the compensation value used by the recording SDR software, as the compensation value will shift the center frequency.
Here are the instructions to obtain the compensation value of the Perseus SDR software:

- Press "Windows-Key" + "R", an imput box appears
- Enter "regedit" into the box and press RETURN
- In regedit, navigate to "Computer\HKEY_CURRENT_USER\SOFTWARE\Microtelecom s.r.l.\Perseus V5\v5.0b - V5 alpha version"
- Locate the key "AdcSamplingRate"
- Right-click
"AdcSamplingRate" and select "Change"
- In the Window, select "Decimal", then copy the value"





- Copy the decimal value and paste it into a calculator
- Divide the value by 80000000 (80 million)

The resulting value is the SDR Clock Deviation value.

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WavViewDX by Reinhard Weiß
2025-01-24
http://www.rweiss.de/dxer/tools.html
dxer@rweiss.de


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