Hello friends,
Last weekend's experiment with the "mystery mode," MFSK8 as it turned out, was mostly successful. I reduced the level of the MFSK8 to 8 dB below the level of the MFSK32, because unattenuated MFSK8 at a piercing audio frequency of 2300 Hz can be rather painful to listen to.
This weekend, we'll repeat the contact information and schedule in MFSK8, but we'll move it to 1000 Hz, which is easier on the ear. With MFSK32 and MFSK8 both at full level, a distorted, other-worldly sound resulted. So I reduced the MFSK8 to 4 dB under the MFSK32. You can still hear what sounds like distortion, but it should be harmless. Probably. I hope.
If you prefer an easy, set-it-and-forget-it decoding experience, just do the MFSK32 at 1500 Hz. If you want more of a challenge, then run two instances of Fldigi, or Fldigi and another decoder such as MultiPSK, or record the program, to see the MFSK8 output. Please remember that MFSK8 must be precisely tuned (it will likely be received a few Hz above or below 1000 Hz) for a successful decode.
Please let me know if you think the simultaneous modes are making the MFSK32 images "noisier."
Here is the lineup for VOA Radiogram, program 55, 19-20 April 2014 (content in MFSK32 centered on 1500 Hz):
01:39 Program preview
02:57 Survey of US software developers, with image
07:08 Planets that wobble, with image
13:38 Cambodia's draft cybercrime law
16:06 Google buys drone company, with image
21:42 VOA Spanish* news story about El Niño, with image
26:23 Closing announcements
*Use the UTF-8 character set. In Fldigi: Configure > Colors & Fonts ...
Please send reception reports to radiogram@voanews.com
VOA Radiogram transmission schedule
(all days and times UTC):
Sat 0930-1000 5745 kHz
Sat 1600-1630 17860 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, with studios in the Netherlands and transmitter in Germany, will include a minute of MFSK64 Saturday at about 1130 UTC (during the new Big Beach Show) on 6095 kHz. And Sunday at about 0130 UTC (Saturday 9:30 pm EDT) on 7375 kHz. Reports to Eric at themightykbc@gmail.com .
Thank you for your reception reports to VOA Radiogram last weekend. I will try to answer them before this weekend is over. And, as always, I look forward to your emails.
Kim
Kim Andrew Elliott
Producer and Presenter
VOA Radiogram
radiogram@voanews.com
voaradiogram.net
@VOARadiogram
Once upon a time in a simple normal world one turned on the radio/wireless and heard normal speaking and music - it was called entertainment and required only the qualification of a normal receiver, aerial and knowledge of wavelength or frequency of the station whose normal programmes might fill hours of listening pleasure.
RispondiEliminaAre we now being used as scientists or their guinea pigs, has the VOA forgotten what it was set up to do ?
Rog Parsons (BDXC 782)
Hinckley, Le10 0NJ
The VOA Radiogram with this new digital system to transmit text and images in digital AM seeking to defeat the QRM and especially the "Jamming", produced by some radio stations.
RispondiElimina