AM broadcast received audio -- local and remote

Audio quality testing this morning involved reception of WWL-AM (870 kHz) on my Flex-3000 transceiver. I recorded audio samples from two places:

1. Flex-3000 speaker output
2. RCForb client program output

Below is a drawing that shows the arrangement of radio and computer software, and the software components that are involved in the two audio paths that I used for recording. I also showed the Ethernet connection to the Internet that provides the path to remote users. The testing reported here used only the data path internal to the PC and the external audio cable.

Click above to enlarge.

Here are audio recordings (about 18 seconds each) for the two audio paths. Click on each to hear the audio recording.

1. Flex-3000 speaker output via audio cable
2. RCForb client program output

Screen shots of the audio spectrum of each recording are shown below. Click on either for an expanded view.

Flex-3000 speaker output via audio cable

RCForb client program output

The RCForb graph shows high frequency content above 5000 Hz that may be due to the wide bandwidth of the Virtual Audio Channel and other data paths internal to the PC. It was not noticeable to me when listening via speakers.

John WA5MLF