First of all: neat idea! A first in shortwave broadcasting, I think: a quintaphonic broadcast. Well, perhaps only quadraphonic last night. Couldn't hear the pirate broadcaster on 6850 kHz. Did anyone? Will try again tonight.
Yesterday (25 May) evening, I went outside with my Tecsun PL-880 portable receiver (protected in a plastic enclosure), close to 40 m away from the house to help minimize the effect of radio-frequency interference (RFI) being generated inside my house and used a Tecsun AN-03L 7-metre wire antenna strung to a nearby tree. The receiver was operated in AM mode with 5-kHz IF bandwidth. The audio was recorded mostly unattended using a Tecsun ICR-100 radio recorder / digital audio player with the mp3 files subsequently downloaded to my Mac Pro for later playback.
Reception was excellent on all four audible frequencies (WRMI: 11580 kHz; ShortwaveService, Nauen: 9690 kHz; ShortwaveService, Moosbrunn: 9620 kHz; WBCQ: 5130 kHz) from a quick check before the actual program started. Also checked towards the end of the program. Virtually no interference (QRM) and no atmospheric static (QRN) on any of the frequencies.
I recorded the whole program on 9690 kHz from Nauen. It was by far the strongest signal with full quieting when the carrier came on. All India Radio was also on the frequency but when the Nauen transmitter came on, it completely overpowered AIR giving a virtually interference-free signal. The full hour was transmitted.
Inside my RFI-infested house, I also operated a second receiver: an Eton Grundig Field BT receiver with just its whip antenna, tuned to the WRMI signal on 11580 kHz. Still pretty good reception. Recorded using a Zoom H2n Handy Recorder. The last minute or so of the program was cut with the transition to the next program.
I could probably have operated more receivers at my house (just outside Fredericton) but I only had the two audio recorders (without getting fancy with my iPhone, computers, etc.).
To get one more recording, I used the University of Twente Web-interfaced SDR receiver to record the Moosbrunn signal on 9620 kHz.
I might try to record the WBCQ signal tonight and check if the pirate station is on the air. Might just get all five stations recorded eventually. And then I could play back (if I get them synchronized) all five "voices" for my personal quintaphonic show! ;-)
Attaching a bit of the Nauen broadcast from last night. I particularly liked the call out to RCI from ShortwaveService. Is that Christian Milling's voice?