7999RE: Re: WBCQ (was "Hollow" sound with TWO Antennas)
- Oct 8, 2013
More as a side-note, it's not all that unusual to see, or hear, an AM station with suppressed sideband...one example is of course WBCQ, and another is CHU Canada, aka Institute for National Measurement Standards, National Research Council of Canada.
CHU 7.850 operates AM with a suppressed lower sideband, and it's a little strange at times for many to tune to it with the DX-394 or Sat 800 in SSB mode, and hear a great signal at 7.850.0 USB, and no signal at all, usually, at 7.850.0 LSB.
In fact, especially in periods of high QRM, 7.850 USB is usually appreciably louder and clearer than tuning 7.850 in AM mode -- making their reason for the selection of suppressed LSB an understandable one.
Joe Rotello / Knoxville, TN / USA
---In RADIOSHACKDX394@yahoogroups.com, <email@example.com> wrote:I tuned up on WBCQ one night with my "better" radio (a Kenwood TS-940S transceiver). Since WBCQ is a broadcast station, I was in AM mode, of course. However, sometimes I can get a better sound by selecting one sideband or the other, depending on the interference conditions, and I was astonished to hear that WBCQ had NO lower sideband! I don't have a spectrum analyzer to visually prove this, but switching from USB to LSB made the signal almost inaudible. Unlike the suppressed-carrier SSB modulation that hams use, WBCQ must have been radiating enough unmodulated carrier to support AM demodulation, but that might explain something of the odd audio you report. If I had tried this with my DX-394, I would have had to retune every time I switched sidebands, because the BFOs were badly off-frequency, and I might not have been able to zero-beat the main carrier very well, because the DX-394 tuning increment is so small. But the TS-940 has 10 Hz tuning, and proper sideband processing.
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