WION 1430 kHz in Ionia, Michigan will be testing tonight. The purpose is to evaluate the matching of their night directional array to their transmitter. This will help ensure better bandwidth for their C-QUAM AM Stereo signal.
The signal will alternate between the night time power of 330 watts and their daytime power level of 4.7 kW starting at 11PM EDT and midnight. (0300 UTC) The duration of the testing is unknown, but probably not more than a couple of hours. Daytime power levels will occur during the experimental period so after Midnight EDT (0400 UTC). All transmissions will occur using their nighttime antenna pattern:
The station will mostly transmit their usual mix of music, but there will be some sweep tones designed to measure the transmitter performance and voice identifications.
You can compare your reception to their live web stream which is at:
See a more detailed listing of the testing tonight from their Chief Engineer Greg Buchwald below:
Update: The updated AM stereo tuner is now online. Less top end distortion. (The Carver needs alignment and probably a few caps changed). Carver tuners, with out a modification on the stereo decoder PLL also have increasing distortion on the bottom end around 50/60Hz. We ran an hour of difficult test music and confirmed it is working properly. Tomorrow night we will take the AM down to measure the night directional array network and finalize the new matching of it to the transmitter for better bandwidth. The current night array is 10.5dB down at 1440khz as compared to the lower sideband at 1420khz (10khz modulation). The resultant quadrature distortion equates to well over 10%; dropping to 4% at 5khz. I expect this to be well under 1% when we are finished. Saturday night is prep work only. We need final measurements to lock in some capacitor and inductor values. I expect the installation of the network will occur in June. After an hour measurements, I will do some audio work. The music will not be your normal selections; it will all be highly separated and chosen to really test the system and allow us to evaluate some minor component changes in the optimod processor and the CRL AGC that precedes it. Comments will be welcomed. Specifically to the DX association that wants to do some listening tomorrow night: carrier will be up and down at 4.7kw and 300W. I can't give specific timing of each power level but expect us to begin sometime between 11pm and midnight edt. There will be few if any tones as we will actually sweep the carrier frequency for some of the tests. Once we have the required data, I will run some tones to confirm the transmitter performance. That will be followed by extended music sets while we perform the audio processing mods and updates. When we install the network at a later date, it will be much easier for us to state specific times of carrier power levels and specific modulation.
Expect lots of reports and discussions on the Facebook group devoted to AM Stereo:
Greg has discussed the possibility of a DX Test using Morse Code, sweep tones, etc. in June when the station will be doing additional testing during experimental hours. Stay tuned for that event.
The CPC is not coordinating reception reports for tonights events, but we would appreciate receiving .MP3, .WAV, or .MP4 video recordings of your receptions. Send those to:
Les Rayburn, N1LF
121 Mayfair Park
Maylene, AL 35114
NRC & IRCA Courtesy Program Committee Chairman
Member WTFDA, MWC