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QSO Recorder: Release Notes


The download comes in 2 pieces. The first file is the base install (a ~3.2 MB download) which includes a non-functional version of the program's exe and all the dlls and controls. The second file is the latest version of the executable (less than 100kB at this time).

Once you have done the base install once, you only need to download the new executable for upgrades.


Unzip the file in a temporary directory and run the Setup.exe program.
Unless you change the default settings, the program will install in C:\Program Files\QSORecorder and create an entry in the Start menu, under "Programs->Ham Software".

If you select another directory, make a note of it.

Then download the QSORecorder.exe file directly into the program's installation directory.
It will overwrite the QSORecorder.exe file created by the main install.

Initial setup

First thing to do is to make sure the transceiver is connected to a dummy load.
Second is to make sure you have a suitable interface between a COM port on your computer and the transceiver's PTT input.

There are a number of suitable interfaces documented on the Internet, as most logging software packages have the capability to control a radio this way. At some point, I will include some interface information on this page. For now, you are on your own. Check the manual for the N1MM Logger ( in the Reference->Interfacing section. It has good interfacing information which you can use.

If you have the choice or are building your own interface, it seems RTS (pin 7 on the 9 pin serial connector) is used more frequently.

For now, interfacing via the parallel port is not supported, but that will be comning.

For reference only, here is the interface I use with my TS-440S/AT.

Thirdly you must select the COM port and pin to be used to key the PTT pin of the transceiver in the software, based on your interface.

There are 2 pins that can be used on a serial port for that purpose: DTR (pin 4) and RTS (pin 7).

These pins normally sit at a negative voltage (between -5 and -15V, depending on your computer, laptops and USB-Serial converters usually deliver -5V, desktops usually around -12V).

When one of these pins is selected using the Settings->PTT menu, the program will toggle the voltage to a positive value of about the same magnitude (+5 to +15V), with only a few mA of current capacity (don't count on much more than 1mA), enough to drive a transistor or an efficient opto-coupler, but rarely enough for a relay.
Make sure you select a valid COM port for your computer. If you select an invalid COM port, the program will refuse to let you click the Tx checkbox (see below).

You must also make sure you have the audio cables connected. Some people swear by commercial interfaces such as the RigBlaster (tm).

There is nothing wrong with those, but in most cases, they are not necessary. I use straight shielded cables between the computer's sound input and output to the radio's rear audio connectors. Depending on the levels output by the transceiver, you may want to use the microphone input of the sound card (low level), or the line input (higher level).

I also use a Y adapter (from Radio Shack) on the speaker output of the sound card so that I can hear through the computer speakers what I am transmitting.

Once you have connected the PTT and audio cables and selected the PTT port and pin, use the File->Open menu to select a .wav file. Any wave file will do at this point, unless you have the radio connected to an antenna, which would be a bad idea in any case.

You can then try and play any audio file on your computer. If your computer is already set to play music, you probably won't have to do anything else and music should come out of the speakers when you click the playback control (the triangle pointed to the right).

If you do not hear anything, the audio stream may be muted.

Click on Mixer->Transmit to select the Playback mixer utility that comes with Windows. Make sure the Wave device is not muted and that the level control for the Wave device is not all the way down. Then check that the Volume Control itself (usually on the left) is not also muted and that the level control for it is not also all the way down.
If you check those and still can't hear a sound, double-click on the SPKIT_8b-short.wav file directly from within Explorer. This should open the default sound player and play the file. This needs to work for QSO Recorder to also work.

To automatically key the rig when you play a wave file, click the "Tx when playing" checkbox on the program's main window.

When the program runs and keys the transceiver, the "Tx when playing" box background will turn red.
If the sound plays in the speakers and the "Tx when playing" box turns red, but the radio does not key, either you have a wiring problem, or you have selected the wrong serial port, or you have another unknown problem. You may want to put a voltmeter on the PTT pin and verify that the voltage goes from negative to positive when the "Tx when playing" box turns red. That will tell you if the program is working and you have a wiring error, or if it is a configuration issue.

If the "Tx when playing" box does not turn red, you definitely have a configuration issue, such as selecting an invalid serial port.

I have tried the program with a USB to Serial adapter and as long as the adapter is installed properly (it shows up in Control Panel->Device Manager), it should work just like a normal serial port.

When you can play a wave file and key the transmitter, you are ready to try and record. You can click the Mixer->Receive menu to select the mixer in recording mode and adjust the level from the radio.

Please note that at least some installations of Windows do not open the recording mixer properly from this menu (I have one of those).

If you are in this situation, just open another copy of the Transmit (Playback) Mixer, then in the Mixer window, click on Options->Properties->Recording. This will open the other side of the Mixer, which will let you adjust the receive levels.

Program Options

The program offers a number of options through the Settings menus.

  • Auto Rewind: this option forces the playback cursor to come back to the beginning of the wave file when it is done playing. Otherwise, the cursor remains at the end, forcing you to click on Rewind (the left triangle with a bar). Turning AutoRewind off can be useful if you want to record at the end of an existing wave file.
  • Debug: this option expands the window and displays additional information that is really only useful to me at this point to troubleshoot the software. It won't hurt anything if you select it.You can also choose the default sample size and bit rate for new recordings. The program will play wave files of any definition, this setting is only used for recordings or new files. For voice, 8 bit at 22.050 kHz is very sufficient. You can chop the file size another 50% by selecting 11.025 kHz sample rate without loosing too much quality. Remember that a 11.025 kHz sample rate allows a theoretical 5.5 kHz bandwidth, more than most ham transceivers provide.If you record over an existing file (the program will let you do that, even though the original file will not be overwritten unless you save it under the same name), the sample size and sample rate will be those of the original file. The sample audio file referenced above is 8 bit sample size and 44.1 kHz sample rate. Keep that in mind if you record over it.
  • Recents: all file names created in a single session are saved in the Recents box, so you can easily get back to a recording you made a few minutes ago using the Recents->View box instead of the more cumbersome File->Open menu. This is convenient if you are comparing different configurations. You can populate the Recents box by sequentially loading multiple wave files using the File->Open menu. You do not have to play the files, simply loading is sufficient.


Start and Stop Markers: You can use the Start and Stop buttons to place markers on a file as the file is being played.

You can also manually adjust the markers using the sliders under the Start and Stop boxes. You can then click on the "Play Start to Stop" button to play only between the markers.

Stn box (Station): you can enter the call sign of the station you are working in this box. When you click "Save", a file will be created with the station's call sign as the file name. If you make several recordings of the same station, you do not have to change the content of the Stn box, the program will automatically add a sequential number to the call sign to make a unique file name each time you click "Save".

When you click on File->New, the program creates a very short (<0.1 second) blank wave file (contains silence) with the parameters you have selected in Settings (sample size and sample rate) in the default directory with the name New.wav. This file will appear as zero length, but you can record on it for any length of time (limited by the amount of memory you have in your system, and the sample size and rate). In this case, the progress indicator will stay stuck on 100% for as long as you record. This is normal.

If you record over an existing file, you can save your recording under a new name and not damage the original file, but if the recording is shorter than the original file, the original file length will remain, so you may have unwanted material at the end of your recording. So, when you want to make a recording, it is better to select File->New first. I will add a specific button to do that more easily in a future release.

Radio setups

Yaesu FT-817: Unfortunately, the radio will not automatically switch between microphone and rear audio input, so even with the audio and PTT cables hooked up, you still need to switch to PKT when you want to transmit from the computer.

Kenwood TS-440S: With this radio, it works pretty much as you would expect, with one twist: It seems that as long as the microphone is plugged in, the microphone will pick up noises when you transmit. I have made a very simple modification to the microphone, involving one MOSFET transistor, one resistor and a capacitor to mute the microphone as long as the PTT switch is not depressed. Follow this link for schematic of the mod.


When recording a QSO in SSB, make sure to reduce the RF gain as much as possible so that the background noise does not come up significantly between words. If you can, also select a SLOW AGC setting. The recording will sound better to the other station.

Multimedia Control compatibility

It has come to my attention that some users have had problem with incompatible Multimedia ActiveX control. This control is a common Windows component which is being upgraded regularly by Microsoft and it is shared with a number of Windows programs and my software apparently is not compatible will all versions out there.
If you get an error message when starting the program indicating a problem with the Multimedia Control, I am afraid you are out of luck, as I do not have a fix at the moment.

I believe the long term fix would be to use the Media Player control, but the API is different and I need to convert my program to use it, something that I have not done yet.

Notes, bug reports and feedback

This program is alpha quality, that means that you should not expect everything to work all the time, as you would expect (but not necessarily get anyhow) from commercial software.

Feel free to e-mail me with comments or constructive criticism.

If you report a bug not listed below, make sure to include as much information as possible on the circumstances of the bug to help me reproduce it.

The program is written in VB 6.0 Pro and uses the Multimedia API of Windows via the Multimedia Control, the MSComm control (to toggle the RTS or DTR pin) and a progress bar control obtained on the Internet. I have tested it on a 120 MHz Pentium laptop running Win95 and on an Athlon 2400 Desktop running WinXP. I have no reason to believe it would not work on other versions of Windows, but I am not an expert in Windows.

The program saves settings in the registry, under HKEY_CURRENT_USER/Software/VB and VBA Program Settings/QSORecorder/Settings (under WinXP).

Version info

Version0.0.29 (May 1,2006)
* Fixed bug when program starts

Version 0.0.27 (Jan 21, 2005)
* New sliders for Start and Stop
* Mixer controls available (Recording control does not always work, this is a bug)
* VU-Meter display (for those sound cards that support it, not my SoundBlaster Audigy unfortunately)
* Can play mp3 files now too (still only records in wav format)

Version 0.0.24 (Jan 4, 2004)
* Added "New" to top menu, reduced CPU load while recording

Version 0.0.21 (Jan 3, 2004)
* DTR and RTS were reverted and only one pin actually worked

Version 0.0.20 (Jan 2, 2004)
* Initial release