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Friday, October 28, 2016

VOA Radiogram Weekend Schedule

Hello friends,
The mystery MFSK32 transmission which has been heard occasionally before and after the VOA Radiogram broadcast Saturdays at 1600-1630 UTC on 17580 kHz was not heard last weekend by any listeners in Europe. It was heard by Mike in Washington state, at about 1542 UTC. The fact that the transmission was heard only on the US west coast introduces some interesting propagational questions about the station’s location. The mystery station also now seems to be transmitting before the North Carolina transmitter signs on at about 1545 UTC with an open carrier. Let me know if you hear and/or decode the transmission this weekend.

Many of us have noticed more hum on the 50+ year old transmitter in North Carolina. The strongest manifestation of the hum within the passband is at 360 Hz. This mixes with the VOA Radiogram MFSK32 signal which, centered on 1500 Hz, extends from about 1250 to 1750 Hz. The “ghosts” above and below the main MFSK32 trace is caused by mixing products: 1250 minus 360 = 890 Hz; 1750 plus 360 = 2110 Hz; and all frequencies between.  Roger in Germany provided this illustration:


For the most part the ghosts do not adversely affect the decoding of the MFSK32. However, the Fldigi RxID is sometimes spoofed by the lower ghost, resulting in Fldigi thinking that the digital mode is centered on 1140 Hz. This prevents a successful decode unless you set Fldigi manually to a center frequency of ~1500 Hz.

This weekend’s VOA Radiogram will be all MFSK32. Let’s hope the adverse effects of the geomagnetic storm that started on 25 October will have subsided by Saturday and Sunday.

Here is the lineup for VOA Radiogram, program 187, 29-30 October 2017, all in MFSK32 centered on 1500 Hz …

1:53  Program preview
3:02  US and China discuss space exploration*
8:19  Planet orbiting Proxima Centauri might be habitable*
15:07  Broadcasters and jammers in the ham bands*
21:11  Photo of Alderney, Channel Islands, by VOA Radiogram listener*
25:23  Closing announcements*

* with image

Please send reception reports to radiogram@voanews.com

VOA Radiogram transmission schedule
(all days and times UTC):
Sat 0930-1000 5745 kHz  (will change to 5865 kHz starting 6 November)
Sat 1600-1630 17580 kHz
Sun 0230-0300 5745 kHz
Sun 1930-2000 15670 kHz
All via the Edward R. Murrow transmitting station in North Carolina.

The Mighty KBC will transmit to North America Sunday 0000-0200 UTC (Saturday 8-10 pm EDT) on 6145 kHz, via Germany. A minute of MFSK32 will be at about 0130 UTC. KBC will also transmit to Europe Sunday, 30 October, at 1200-1300 UTC, on 6095 kHz. A minute of MFSK32 will be at about 1230 UTC. Reports to Eric: themightykbc@gmail.com .

DigiDX will transmit MFSK32 and probably other modes:
Saturday 2030-2100, 6070 kHz, via Channel 292 Germany
Sunday 0530-0600, 6070 kHz, via Channel 292 Germany
Sunday 2130-2200 UTC, 15770 kHz, via WRMI Florida
Sunday 2330-2400 UTC, 11580 kHz, via WRMI Florida
For schedule updates, visit DigiDX at http://www.digidx.uk/  or https://www.facebook.com/digidx/

IBC (Italian Broadcasting Corporation) has a broadcast to Europe on 6070 kHz and new 3975 kHz, Wednesdays, at the new time of 1800-2100 UTC.  The MFSK32 and Olivia 16-500 are still at 2030-2100 UTC. IBC has also added a medium wave transmission Saturday 2000-2030 UTC from Radio Studio X, 1584 kHz, in Terni, Italy, with MFSK32 at 2025-2030. IBC also has MFSK32 transmissions via WRMI in Florida: Friday 0125-0200 UTC on 9955 kHz (Thursday 9:25 pm EDT), part of its 0100-0130 broadcast. And Saturday at 0155-0200 UTC (Friday evening 9:55 pm EDT), on 11580 kHz, part of its 0130-0200 broadcast.  See http://ibcradio.webs.com/ for the complete schedule and contact information.

Thank you for your reception reports. I made some progress this past week sending out the galleries from program 181. More emails will be sent this weekend.

Kim

Kim Andrew Elliott
Producer and Presenter
VOA Radiogram
Twitter: @VOARadiogram (especially active during and after broadcasts)