using a pc with soundcard as a vlf receiver

#Using A Pc With Soundcard As A Vlf Receiver Generator Is Sound#
#Using A Pc With Soundcard As A Vlf Receiver Generator Using A#

Some high performance soundcard can sample up to 96 KHz. Because a typical soundcard can sample up to 48 KHz. Computer soundcard works as a VLF receiver.

Using A Pc With Soundcard As A Vlf Receiver Generator Using A

This receiver covers the frequency range from virtually zero to around 30MHz and is ideal for listening to VLF because it can't be overloaded by local VHF broadcasts.Using a 'Spare' Computer & Spectrum LaboratoryA PC as VLF receiver - Using a PC with soundcard as a VLF receiver, how to use your PC as a receiver for narrow-band signals in the VLF radio spectrum by DL4YHF Hits: 801 Votes: 1 Rating: 8 A Simple Radio Receiver - Development of a simple modular radio receiverSimple setup for monitoring of VLF signals using vlfrx-tools. One of these is the Andrus SDRMk1.5 made in Estonia. Overview PC with soundcard used as VLF receiver The Stanford University.Since I experimented with reception via the computer sound card, I've purchased several 'Software Defined Radio' receivers. Ultra Accurate Audio Frequency Generator Using a 'Spare' Computer & Spectrum Laboratory For Sound Card CalibrationSome of the more advanced VLF receivers do use frequency conversion and digital. If you use long wire antenna or long whip then connect it to the main wire of the line-in. Connect your antenna to the line-in or microphone jack.

Using A Pc With Soundcard As A Vlf Receiver Generator Is Sound

A signal generator output.One of the more difficult tasks to perform without the aid of a highly accurate signal generator is sound card sampling rate calibration. 6a) or by a PC soundcard with test tone generator software (Fig. The sound card sample rate is compensated using a 1PPS signal source froma GPS receiver.who would like to start using the receiver immediately. This article shows an example of a simple setup used for VLF monitoring and ebnaut decoding.

All that is needed is a spare computer (with a 96 kHz sampling rate soundcard - 48 kHz may also work) and Spectrum Laboratory software.The concept involves using two features that are built into the Spectrum Laboratory software - the Frequency Error Compensation/Calibration routine and the Test Tone Generator. Described here is a relatively simple method to generate extremely accurate audio tones, rivalling those from a GPS referenced signal generator. In the past, schemes have been devised using Loran to provide a cal signal but this option no longer exists. For those lacking test equipment the job is considerably more difficult. For stations that have GPS referenced signal generators the cal procedure is simple.

With any luck you'll see a number of VLF signals in the waterfall as in the picture below.Open the Spectrum Lab Components window and press the 'SR Cal' and 'Signal Generator' buttons and to activate those functions and click in the grey switch box to make the connection as shown. For a 48 kHz sampling rate sound card these enties should be 48000. At this point check Options > Audio Settings to see that Sound Card Sample Rate is at 96000 and that the entry in the Sample Rate Calibration Table (Hz) for Input Calib is 96000. Select the appropriate input under Options > Audio Settings. Start Spectrum Lab and load the soundcardcal.usr file from File > Load Settings From.

If there is a problem this box will show red. If the signal is usable the Status box will display a yellow 'Collecting data for Block #1, #2 or #3' message while data is being gathered. Once the station is selected, check the Enabled box and press Apply. You may wish to select another station depending on your geographic location (see Notes below). In the Frequency Error Compensation/Calibration window I chose NAA at 24 kHz as it is quite strong here in the northeast.

Lower sampling rates would have to be calculated from the 96 kHz value and entred manually.Notes: The sound card sampling rate determines the frequency range of VLF reception. In this example, 96005.034455 would be divided by 12 to give a sampling rate of 8000.42 which would then be entered into the WOLF Config > Receive Options Sample Rate box.The 'Current SR' can be entered into Spectrum Lab memory in place of the nominal 96 kHz sampling rate value by pressing > to the right of the Current SR box in the Frequency Error Compensation/Calibration window. Using WOLF as an example, the 'Current SR' as displayed in the Frequency Error Compensation/Calibration window is scaled to the desired sampling rate. This still requires reception of a VLF signal and the Frequency Error Compensation/Calibration routine to determine the exact sampling rate. In that case, one can dispense with the second computer and the Test Tone Generator and just enter the appropriate 'cal' information in an application. Note that this level of accuracy extends to all frequencies from the Test Tone Generator.If one is not interested in the signal generator aspect, and only wants to calibrate a sound card, there is a shortcut.

In the northeast, using an e probe antenna, I've verified that the following stations can be used. In this case an alternate VLF transmitter can be used as long as the signal is strong enough. A 48 kHz sampling rate card will not be able to receive NAA on 24 kHz as the MSK modulation components are above 24 kHz as well as below.