Installing and using HDSDR


Version 2.80 (March 2020) As usual look at for new features. A good write-up for the changes in v2.80 here June 2022 v2.81 beta 6 available, as usual newcomers may find the last stable version (nowstill 2.80) is safer.

HDSDR is a derivative of Alberto's Winrad, parts of these notes apply to this and any other derivatives.

HDSDR is still being developed, new features added. We are promised a version 3 at some time.

My experience covers SDRs using the Si570 like the Softrock, the FCD, RTL dongle, Airspy, RX-666/888 and Elad.

HDSDR may be used with many other SDRs. June 2018 HDSDR is used with the ICOM R8600 in IQ mode.

Installing HDSDR:-

Installation with references to SDRs like the Softrock. A section lower down this page.

Download HDSDR from here

While you are there read the other pages, note the link to Alberto's original help and YouTube.

Execute the installation.

Note the folder where it installs, you will usually need to find it in order to place a DLL file in there.

Look here for DLLs and instructions for use with many radios, SDR and conventional.

November 2014, USB2 controllers as in the Softrock and other early SDRs. There have been reports that these are not working in USB3 sockets. Try a different socket, there should be a USB2 socket. Or, possibly the work-round linked here

June 2018 and 2020 still! In certain circumstances Windows 10 updates have disabled sound devices. This could affect HDSDR, devices or applications used with it.

Look here [Also refers to the microphone audio input.]

Keyboard Shortcuts.

Options - About HDSDR leads to an HTM file link, also in the Start Menu. The file is actually located in the program folder. Blind people will find that very many of HDSDR's features may be reached by the keyboard. The keys affecting tuning can be particularly useful for everyone and some undocumented features can only be accessed by the Keyboard.


Select the soundcards and bandwidth (sample rate) if necessary.

Click "Start" or press F2.

You may need to set the Windows mixers and properties to suit recording (input) and playback (speakers) and sample rates of these devices.

Look at Read the mouseovers. Look at all the Options.

Make sure that the IQ Swap (Options - Input Channel Mode for RX) is set correctly. Ensure that SSB signals are on the correct sideband and that tuning is correct, that higher frequencies ARE actually to the right.

Note if you have not set "Options - Callibration Settings - Input Channel Calibration" (Image rejection) you may see images on strong signals. Do not be confused.

Channel Skew (Image Rejection) Adjustment

At "Options - Calibration Settings - Input Channel tab."

Below I show the important TX image rejection panel seen when in transmit mode. The RX panel is similar.

For receive the image has to be set manually. Maybe an automatic system will eventually be implemented.

"Sample Delay" is only needed for a few, mainly old Creative, soundcards. Try various combinations if you see very little difference in the two signals.

This page gives full details.

Tuning HDSDR

Note the Tune/LO figures are Hz. WWV 10MHz will show 10.000.000. The 70cm ham band 432.525.000.

SDR beginners:- Note that "LO" sets the centre of a band of frequencies. "Tune" shows where you are within that range. Simply changing "Tune" with the mouse will not move from that range. The LO must be changed by the mouse or by any of the other tuning methods.

Fixed frequency SDRs:- Set the LO to the exact crystal frequency then use "Tune".

At the centre of the display you may see a sharp spike. The effects of this spike may be hidden. "Options - Calibration Settings - DC Removal" and set RX DC Removal to "Auto". Do not use this centre area unless you have to.

Place the mouse cursor on a digit. The mousewheel or left/right clicks will set it. Set LO to, say, 10KHz from the required frequency. See Options.

Look on the waterfall for the signal, click on it. Tuning steps are set by band, (upper drop-down) or by the lower drop-down. If you do not like the new default tuning steps set the top drop-down (Band) to "-off-".

Drag the shaded area that represents the signal bandwidth.

Drag the frequency scale to move up/down.

Use the upper drop-down to select a band, the limits are shown by a colour bar below the frequency scale. Click tuning jumps to the preselected step in the lower drop-down. If you want random frequencies set select 1Hz (or "-off-" in the upper drop-down).

Click the red arrow at the end of the tuning scale to increase LO frequency by the visible spectrum bandwidth or use Ctrl+PageUp on the keyboard.

Note the two VFOs. Click the "A" or "B" next to the LO frequency.

Look at keyboard shortcuts, some useful tuning aids. Details in the htm linked in the Start Menu. Or a link shown when you press F1. (Also shows other useful links.)

And direct entry with the numeric keypad.

Quick Tune:- Type KHz - Enter

Or type MHz, for example 14.2 - letter "M"

This will give you a fixed offset from the centre. This is recommended for TX operation, you set your TX image calibration at a fixed audio frequency so TX image rejection will not vary so much across a band. (Like PSDR).

Or tune with the mouse over a band, find a station, or frequency, you wish to call, right click. Or, left click and press "C" on the keyboard, the offset is then applied.

Then TX image will not need much tweaking once set for the band in use. This should also help for receive image rejection.

Lock Tuning and LO.

Right click on "Tune" and "LO" will lock either or both so the frequency is fixed.

AFC and "Tune" legend next to the tuned frequency.

When the AFC button is clicked the colour of "Tune" shows whether the AFC is locked (green) or not (red). Yellow shows when loosing lock after having once locked.

When AFC is not activated it acts as a tuning indicator, green when exactly tuned.

CW Zap

Click this to net perfectly.

"Despread" for EME described here

CW Offset:- CW Pitch

Hold the keyboard control key and left hand mouse button to drag the centre line of the CW filter. OR Control-Click when the green cursor is on the required frequency.

Or just click on the yellow "CW Pitch =" and a box appeas.

Filter Widths

The red lines on the lower spectrum are the filter limits. You will not see the right one if zoomed in. Drag them.

S Meter calibration

Click here for more information about using HDSDR for measurements.

Calibration:- Options - Calibration Settings - S Meter tab.

On that tab two ways are described.

The normal calibration is at -73dBm, 50uV into 50 Ohms, S9 . But any known value may be used.

Note by clicking on the figures under the S meter S units or dBm is displayed.

Precise measurements may be made by zooming the Spectrum Scaling, the two lower controls.

Also available on main spectrum.

The level in dBm is displayed next to the cursor, in the selected RBW and also normalised to 500Hz bandwidth.

"RBW" explained here.

Squelch, click on S Meter scale.

Level shown by red line on the scale. Care! Sometimes an accidental click is the reason for no audio!

Notch - Noise Blanker - Noise Reduction

Read the mouseovers, this applies to most of the buttons.Clicking on one of these buttons brings up its adjustment slider. A right click on the button hides the slider.


Even this has a mouseover!

And note the level in dB is displayed by placing your cursor on the level slider.

Frequency Manager

Radio Bands, User defined entries HFCC, PERSEUS and EIBI shortwave list.

The lists are in your documents, for example C:\Documents and Settings\User\My Documents\HDSDR\CSV EIBI is done automatically, Select EIBI and use the drop-down menu on this button. Or you can download the latest yourself. The HFCC and Perseus buttons drop-down have links for manual download.

User:- Type in at bottom - Add.

Waterfall/Spectrum Display.

Note the sliders and controls under the waterfalls. Again mouseovers to explain. Adjust spectrum upper/lower dB limits, waterfall speed and definition. Zoom in on the frequency in use.

Click on picture below for an example.


All options now here

"Show Upper Display" Removes everything except the upper spectrum and waterfall. Drag this window either way, very big or down to a very small size. "Esc" returns to normal.

De-selecting both the upper and lower display just leaves the controls, no spectrum or waterfalls.

Within certain limits the HDSDR window may be resized by dragging the edge or corner. For a wide display it can be dragged to span two monitors.

Right click-drag on the frequency scale alters the spectrum/waterfall ratio, as far as selecting one or the other.


Right Click a choice of formats, examine the whole spectrum later if you wish.

Note, you may use this to schedule frequency changes, just set a 2 second recording time.

Play a .wav recording:- To play a recording HDSDR may be started by dragging the file to a HDSDR Desktop shortcut.

Record levels as CSV:- periodic and explicit level logging into .CSV file Look at the Keyboard Shortcuts.

Single-Shot write S-Meter level to CSV Ctrl + Shift + Insert

Minimum Power averaging in ms for CSV Ctrl + Insert

AutoSave S-meter level to CSV on Level-Change Shift + Insert

AutoSave S-meter level to CSV periodically Insert

CSV saved on my computer C:\Documents and Settings\User\My Documents\HDSDR\CSV

Options - Calibration Settings - Frequency Calibration tab.

Do not use HDSDR's calibration feature with a Si570 controlled Softrock. See above link.

Frequency Calibration for Other SDRs

For receivers that do not have a calibration facility use the above tab. When the phase indicator stays still check that the two boxes at the top show correctly and click "Calculate". Check the tuning is correct, if not "Reset" cancels, try again.

Converter/Panadaptor controls. See my other pages

Use the menu OR a Right Click on "ExtIO" brings up this tab.


A specialist addition for closely examining signals.

The AF spectrum is used. Note that a click on "Spectrum" will activate this mode, further clicks will restore normal operation.

Further information here


One way to do this is just to drag the DLL to the shortcut.

HDSDR will start using that DLL

Set Different Profiles.

HDSDR can use completely different settings for each profile. These are stored in the Windows' registry at HKEY_CurrentUser\Software\HDSDR\<optional profile>\. This allows

HDSDR to be started with many different configurations.

Making custom profiles:- (for example per receiver) using a command line option "-p profilename" (the profile name should not contain spaces or other local characters)

Make a shortcut to HDSDR.exe, rename it. Right Click -Properties. To the end of "Target" add -p your profile name - Apply.

When opened with that shortcut all settings are saved under that profile.

Any number of profiles can be saved to avoid changing settings.

(There are usually spaces in the Path so inverted commas have to be used as in the example below. These will be present if needed.)

Select a DLL with a Shortcut

Provided you have put the required DLL in the HDSDR folder just enter the name on the "Target" line. This one is for the RTL dongle.

HDSDR starts with the RTL DLL selected and with the "RTL=VHF" profile.

Rather than putting the DLLs in the program folder you may store DLL files elsewhere. In that case the whole path must be entered like:- ....\HDSDR.exe "C:\my files\extios\ExtIO_FCDplus.dll"

And top left of the HDSDR window reminds you of which profile you are using. "HF-USB" in this case.

If this looks wrong it is because I prefer "Misc Options" Swap Spectrum/Waterfall. And I have increased the relative size of the spectrum display by right clicking and dragging the frequency scale.

And also I have set the "Spectrum Scaling" sliders to suit my purpose.

Other Startup Options:- Run HDSDR /? as a Command Prompt in the HDSDR folder. A box is displayed showing what else may be specified when starting a HDSDR profile.

Version 2.80

Installing an Update:-

To maintain all settings just install over the previous version.

Saving Profiles

April 2021:- The 2.81 beta version has an option to save a single profile. Options (F7) - Misc Options - Export HDSDR settings. Note carefully where HDSDR puts this file. You may rename it to something meaningful keeping the .reg extension. All profiles may be saved this way, any corruption restored by double clicking the associated saved .reg file.

Uninstalling HDSDR:-

Care! If you have more than one installation or profile then uninstalling one will reset all other HDSDR installations and profiles to default.

To set ALL HDSDR's settings to default:-

Care! go to Options - Misc Options - Reset to Factory Settings. All profiles will be deleted.

Corruption of just one profile:-

I had one instance that always started in CW mode, no other problem. I started it, corrected the mode. Keeping that instance open I went to Regedit and deleted the key. Then closing HDSDR recreated the registry entry and restarted correctly.

For problems that can not be solved in this simple way:-

First make a note of any settings, for example IF or converter frequencies. Using Regedit go to the Windows' registry at HKEY_CurrentUser\Software\HDSDR\<optional profile>\. Delete the key, and sub-keys for this faulty profile.

This will not delete the shortcut. Just restart using this shortcut and re-configure HDSDR.

Advanced users may wish to save the registry keys when profiles are setup. Then in the rare event of a corruption settings may be instantly restored.

By saving the complete HDSDR key all profile settings are saved. An individual profile might be extracted from here but saving each profile might be safer. To extract a profile from a complete backup create a Profile name.reg file with the header from the backup "Windows Registry Editor Version 5.00" for example then a blank line. Under that paste everything from that profile in the backup including the "[HKEY_CURRENT_USER\SOFTWARE\HDSDR\Profile name]" heading.

To Only Delete the "Default" Settings:- select "HDSDR" in the left pane and select and delete all in the right pane. (The top entry "Default" can not be deleted.)

Other Menu Settings

Bandwidth [F6]:- Sets Input and Output sample rates. Proper operation requires that you set these at rates your SDR system will support. Output rate may be set at 192000 to enable wide FM reception. Output sample rates are saved for each mode.

Options [F7]:-

Select Input. WAV file playback. ASIO if you have a soundcard that supports ASIO. Note ASIO may not be used when in transmit configuration.

Visualisation. Many settings to suit your requirements.

Input Channel Mode. IQ for SDR radios. Other settings for mono radios and special purposes.

Output Channel Mode for RX. Normally to both channels, or to suit. IQ mode sends IQ signals to other software, see my other pages.

Misc Options:-

Autostart HDSDR runs when started.

set LO <-> Tune Offset and Tune fixed to 'LO <-> Tune Offset' here

Various other Misc Options including "Show Status", "Export (Registry) Settings", "Reset to Factory Setting" (Delete ALL HDSDR registry settings.)

Mouse Wheel. Sets tuning preferences.

Help/Update:- Check for updates. Keyboard Shortcuts. HDSDR web pages. Feedback/Bug Reports.


For TX soundcard selection "SDR TX Support" must be ticked.

When in TX mode IQ swap and image rejection for TX is enabled and the Volume/AGC sliders change to mic gain and power output.

In transmit mode the transmit filter width is adjustable by dragging, just as with receive.

An external receiver is required to check IQ swap and setup TX rejection.

This page gives full details.

Softrock-type soundcard:- RX/TX PE0FKO produced a DLL, with CFGSR V2.6, to go with the latest version of HDSDR, ALL THIS DOES IS PUT A SOFTROCK TO TX, so far no CW keying.

The only way at the moment is to use the "Return" key for CW. But see "CW Operators" below.

Two soundcards required but do not forget VAC acts as a soundcard. The second sound device can be a cheap one used for the mic and speakers.

Do not forget to tick "SDR TX Support.

No ASIO for TX. Spacebar works PTT to TX.

Below, set to use a COM port to set HDSDR to transmit.

This can be a virtual port connected to other software.

Third party software may be connected with VAC. WSPR, for example can be used with CAT (TS2000) to set the Softrock to TX and change frequency.

When in CAT mode HDSDR may be put into TX mode by setting CTS or DCD, pins 8,1 high, selectable in the Menu, as above. Also DTR pin 4 will activate TX mode. You may just put this pin high, through a virtual COM port to another program, no CAT required at the other end.

Below, sets the Mic input, one or both channels. The IQ mode is for special uses.

Tone Generators:- Press Ctrl-Shift-G when transmitting. Pressing Ctrl-Shift-G again switches to next generator. This will not work for CW mode. See here HDSDR tone generators. (and the reason Softrock CW is not supported.)

CW Operators.

I think really fast operators will always have trouble with PC SDR, too much latency.

But many report that good results may be had up to around 25 WPM. QSK seems impossible. Rocky is possibly the best software. September 2015 Problems with Vista or later? TRY ROCKY v3.8, ALEX HAS USED WASAPI DRIVERS FOR LOW LATENCY.

With HDSDR transmit is not fully implemented, just the "Return" key, maybe try this This is suited for earlier RXTX Softrocks I give information how the Ensemble could be modified.

Note the various links on the pages, for example, "Next post in topic >>, Show all 4 messages in this topic" to get the whole picture.

Some have used CW successfully with a keyer and SSB mode. No sidetone latency. Tuning needs thought. describes one way. You may have to click links on the page to see all the messages. Note HDSDR's transmit bandwidth may be reduced to avoid any IMD effects. And And and read other posts in this topic.

Warren offers another way requiring some modification, an Arduino keyer/sidetone:- note Warren corrects the subject, it is not break-in.

At the end of this post Vojtech tells of his DLL that enables fast break-in with a Peaberry SDR.

The keyboard "Shift Control U" when in CW TX mode is the equivalent of holding down the key, constant carrier.


Here:- CW-Skimmer using HDSDR's IQ out facility This page details how many digital modes may be used with HDSDR including more on interfacing with a conventional transceiver.

USING HDSDR with digital mode software, Fldigi and WSPR shown .

And below WSPR-X and HDSDR. And use of HDSDR with CAT interface of a transceiver.

This uses CAT to control HDSDR.

After setting the required COM port and baud rate go back and Click "activated"

And this is WSPRX set up so it tunes HDSDR and puts a Softrock to TX. WSJT-X will have the same settings. just the setup tabs are different.

HDSDR's audio in/out is connected to WSPRX via VAC.

And the CAT is connected by a Virtual Serial port. For example COM0COM

19 Jan 2013. WSPR-X is now replaced by WSJT-X which includes most JT modes.

WSPR-X is available at Windows v0.7r2960

Use HDSDR with an Ensemble RX (or similar) to control a transceiver.

And the transceiver also controls HDSDR and hence the Ensemble.

This is a composite showing HDSDR tuned to 7.186,550 my FT847 also tuned by HDSDR.

Also the OmniRig settings. To activate, bring up OmniRig setup and click OK.

Make sure the Ensemble is working correctly with HDSDR first. Then all that is needed is to setup the CAT as shown.

Use HDSDR With a SDR Connected to the IF of a Receiver or Transceiver

Panoramic display, wideband SDR receive for voice and data, click on a signal and transmit.

RTL Dongle

A cheap dongle may be used as a wideband SDR. Different tuners will work from 25MHz to 2GHz some with a L band gap. Performance is not outstanding but can be adequate. Ebay is a good source. There are upconverters available so HF may be received. I do not reccommend the cheaper direct conversion option.

For use with HDSDR:- The Zadig driver has to be installed and the RTL DLL placed in the HDSDR program folder. Select this when starting HDSDR.

Driver installation on HDSDR's site

HDSDR's "SDR Device" (was ExtIO) button brings up the dongle controls.

The important dongle RF Gain adjustment is available on a slider by clicking "RF" by the control buttons and the sampling rate is adjusted by clicking the "Bandwidth" button .

More than one Dongle?

Here is a method for identifying each by their PPM and use in HDSDR

More if needed:- Instructions and a link to HDSDR ExtIO for RTL USB dongles — Read more

DLL At the top, select "Zip".

Zadig driver If you are new to this read carefully and use the install package. At the top 1 "Download the self-contained installer"

This shows Zadig setup.

January 2017 v 2.75 Some of the new features were introduced especially for the RTLSDR Dongles:

- 8 bit support, of course - displaying the RF (ADC) level in dBFS allow working with deactivated Tuner AGC – NOT overdriving/clipping the ADC. This will also ease making good recordings.

Here HDSDR and a dongle SDR used with an HF upconverter. RTL dongle used as an IF panadaptor with HDSDR.

This must be the definitive list of software for use with a RTL dongle.

Funcube Dongle

The Pro and ProPlus may be used. The correct DLL has to be placed in the program file. There are HDSDR DLLs which integrate the FCD controls with HDSDR. Found here

Supports multiple FCD Pro+ dongles, read the README in the zip.

HDSDR's SDR Device (ExtIO) button brings up the dongle controls for special "Bias T" settings. Do not touch unless you understand what it does!.

The important dongle RF and IF Gain adjustment is available on a slider by clicking "RF" and "IF" by the control buttons. Note that different situations will require different combinations of RF and IF gain.

"RF Gain" has four positions which are the four possible combinations of LNA and Mixer gain ON/OFF. Try both middle positions, I find the lower position (+10) sometimes gives overload while the upper (+20) does not.

Does the FCD work with Newer computers? There have been reports of the FCD not being correctly configured when it is plugged in.

Try removing ALL USB devices, ALL including any keyboard or mouse receiver t hen plug in the FCD. Then plug in your mouse, keyboard, other devices. If there is still a conflict, maybe the keyboard does not work, then try other sockets or use a hub.

Read here for more information and some ways of using the FCD. is the main site. Look at the drop-down menus when you hover over the headings in the black bar.

Running HDSDR and the FCD Dashboard Simultaneously

For a visual display with Doppler correction, lots of information here.

RX-666, RX-888

These radios from China will run on HDSDR with ExtIOs and will also run on SDR-Radio.

December 2020 ExtIO DLLs for HDSDR. Up to 30MHz span on the RX-666, 60MHz on the RX-888 but not on VHF, a downconverter is required.

Oscar Steila:- Pages showing latest ExtIO_DLL development here ExtIO_sddc.dll v1.01 ( See the rest of his blog ik1xpv - Hamradio software & hardware (

Franco's summary of Firmware and ExtIOs Some notes on firmware and ExtIO versions (

Franco's summary of the clocks within Some notes on clocks ( Note Howard's amendment in a following post.

Adalm Pluto

Start here:- ADALM-PLUTO Overview [Analog Devices Wiki] Note "PlutoSDR will populate as a Mass Storage Device when plugged into a computer." Instructions contained within the Radio!

In case of problems:-

Cypress drivers:- Drivers for EZ-USB® FX1™ , FX2LP™ , and FX3™ - ... | Cypress Developer Community You need the FX3 drivers, it seems most find these work.

I used the drivers linked at the bottom here:- How to Install / Re-install oCam USB Driver for Windows – WITHROBOT These FX3 drivers worked for me when my Windows 10 did not accept the others.

ExtIO DLL for HDSDR GitHub - lesha108/ExtIO_Pluto: HDSDR ExtIO DLL for ADALM PLUTO

This works for the extended Pluto 70 - 6000 MHz See "Updating to the AD9634" here Customizing the Pluto configuration [Analog Devices Wiki]

More Pages About HDSDR, Advanced Topics.

RX and TX Image adjustment for HDSDR This page should help for other software.

Fundamental settings for digimodes beginners, receive only. r_receive_digimodes

Use with digimodes

This page gives many details about HDSDR and digimodes. With examples of CAT and DDE (Orbitron controlling HDSDR for Doppler compensation).

My preferred way for a HF panadaptor.

Ideally take the Ensemble antenna connection from the transceiver. Using an Ensemble with a conventional transceiver as a panadaptor.

Using with a conventional receiver or transceiver as an IF panadaptor. Ham Radio deluxe controlling HDSDR with DDE .

Using HDSDR with a RTL dongle And using the dongle as an IF panadaptor with a conventional rig.

How to set HDSDR for measuring signal levels,

can be reasonably accurate if you have a standard. Using HDSDR for signal measurements, the S meter and Spectral Display.

Autocorrelation (and Cepstrum),

new features November 2013. If you want to use this feature you probably know more about it than I!

Virtual Serial Port for CAT

Streaming Audio Between HDSDR and Other Programs

RX and TX Image adjustment for HDSDR This page should help for other software.

Alberto's Winrad help partly updated for HDSDR.

Using HDSDR with Wine on Linux

HDSDR version of CSVUserlistBrowser The video shows RDS Spy with a frequency list. EIBI Aoki and HFCC lists may also be used. In German but use Google translate. The PDF instructions are English.

First-time installation with a Softrock-type soundcard SDR.

Softrock:- you need CFGSR and the USB driver but may well already have them. Driver CFGSR Current version 2.6 which you download from with automatic installer and new guide on that web page. (Click on "msi" the correct msi file...) Note instructions on that page.

As things develop my screenshots may show an earlier version of CFGSR or HDSDR but all features will be found.

Download HDSDR from here

While you are there read the other pages, note the link to Alberto's original help and You Tube.

Execute the installation.

Later versions of Windows have security features that make altering the contents of "Program Files" difficult. It is probably not needed but installing HDSDR somewhere different "C\HDSDR" perhaps may avoid such problems.

Note the folder where it installs, you will need to find it in order to place a DLL file in there.

The paragraph below is to install Softrock type SDRs, look here for DLLs and instructions for use with many other radios, SDR and conventional .

Softrocks and others using the USB ATTiny controller.

Winrad and its derivatives need ExtIO_Si570.DLL to be placed in the program folder. There is a shortcut to it in the CFGSR Start Menu folder. COPY it to the Program folder. (Drag with RIGHT mouse button) Or navigate to the program file, eg C:\Program Files\CFGSR\ExtIO_Si570

When starting you probably will NOT get this.

But if you do select the DLL and "Open"

Current versions of HDSDR open in a window. This window may be resized. (The original Winrad has a fairly basic interface, when first started it will fill the screen, some versions can be made to start in a window.)

Note the links in the HDSDR Start Menu. Keyboard Shortcuts may be useful. Direct frequency entry, shifting up and down bands in defined steps. Many other features

In the set up you must select the Input Source as 'SoftRock V9.0 Si570'. (This is usually preselected.)

MME drivers will work with all cards.

If you have ASIO it may be used only for receive.

For use with transmit a second soundcard (or VAC) is required MME drivers only. Some raise concerns about this, ASIO drivers are better but perhaps the actual advantage is small.

You probably will not have so many sound systems, here I have selected 3 different ones. For transmit two are required, one may be VAC for data modes.

You may need to set your soundcard mixer to set the correct input, keep the RX input as low as possible so the HDSDR noise level rises only slightly. Disable all special effects.

Only select a sample rate your card is able to use. 48000 is a good start, all will be able to use this.

Press keyboard "H" or click "SDR Device" (ExtIO)

The green dot should be present, bottom left. and the connected information Note the Manufacturer and other fields do not always show any entries.

If the USB is not connected got to the USB tab, check it is present, select it and "Open"

If there is nothing here you will have to diagnose the problem.

Make sure that the Options - Swap I and Q Channel for RX is set correctly. It normally needs to be ticked but ensure that SSB signals are on the correct sideband and that tuning is correct, that higher frequencies ARE actually to the right.

Note if you have not set "Options - Channel Skew Calibration" (Image rejection) you will see images on strong signals. Do not be confused.

Calibrating the Si570.

This page is my start at updating Alberto's original "Winrad" instructions to suit HDSDR.It has not been completed but it does include some features I have not mentioned on this page.

Contact HDSDR

The correct way for reporting bugs (and other feedback) is printed in the "Options - About/Help/Update" dialog:

Please report via eMail to Mario <>

If you can attach additional information to the report: * make a screenshot of the Status dialog (Options / Misc Options / Show Status), which also shows operating system version, CPU type, ExtIO DLL, .. * export the settings: Options / Misc Options / Export HDSDR settings * possibly additional screenshots * possibly> additional RF / AF recordings and of course a detailed description of the error itself. (LC).

G4ZFQ January 2013 and continuing updates Nov 2020.

alan4alan at googlemail com

More of my pages related to SDR Main Index page.

Setting up CFGSR for different versions of the Softrock

All aspects of the Softrock SDR a big page with lots of links but you should find answers to most questions.

1 The Si570

2 Getting and Making Softrocks What computer?

3 Building a Softrock. Or look at

4 For Information Surrounding the Softrock VHF converter, MOBO, PAs, Panadapter for use with conventional rigs etc.

5 Soundcards Setting up, USB, problems.

6 PIC/PICAXE control of the Si570, Tony's first method. switched control without a computer. Reprogramming the PIC (and PICAXE)

7 Parallel Port Control of the SI570.

8 USB Control of the SI570 Information, driver installation. BPF control.

9 Serial (COM) Control of the Si570.

10 Some Stand-alone Controller Kits Control the Si570 independently. Links to other SDR kits.

The above information is availble, contact me. Notes and links for all soundcard SDR software I know. Including Modes not yet Supported by these SDR Programs. Audio Files to Test Software Without a SDR And a few links to some of the many SDRs on the web. Check them out without owning one.