Re: [IRCA] 918 kHz DU English Puzzle

[Chuck Hutton <charlesh3@xxxxxxx>]

Gary -


The amplitude level of the recording would have no relation to the DSP filtering.

And the DSP filtering and tuned circuit Q might roll off a bit of the audio frequencies above a few kilohertz, but I wan't trying to point out that rolloff. Instead, the audio rolls off starting about 300 Hz. A bit of equalization was able to restore a flat passband to almost 1700kHz. To my ears, the equalized, higjh pass filtered file is distinctly easier to understand, YMMV.

There are 2 mono tracks in your audio file, causing a larger file.


Chuck



________________________________
From: Gary DeBock <d1028gary@xxxxxxxxxxx>
Sent: Monday, April 23, 2018 8:28 PM
To: Chuck Hutton; Mailing list for the International Radio Club of America
Subject: Re: [IRCA] 918 kHz DU English Puzzle

Thanks for your investigation of the 918 file, Chuck and Theo.

<<< It was a difficult file to study. The level was way too high: Audacity tells me it had to be lowered by 7 dB just to prevent clipping. After adjusting the level I then had to adjist the equalization as it was very muffled/ >>>

Both the 1 kHz DSP filtering of the C.Crane Skywave Ultralight model and the very high-Q tuning system of the FSL antenna tend to clip off the higher frequencies in received DX station audio. The extent to which this side effect occurs depends somewhat on the gain provided by the FSL antenna, with the larger models clipping off more of the high frequency audio. Although improvements have been made in recent Ultralight DSP chips, it is still unrealistic to expect the Ultralight + FSL combination to have the audio fidelity of a $1000 Perseus-SDR + broadband antenna, unless the Ultralight's DSP filtering is set at a level too wide for serious transoceanic DXing.

Gary

On April 23, 2018 at 6:04 PM Chuck Hutton <charlesh3@xxxxxxx> wrote:


Gary -


At 2:44 I hear a phone number and a  mention of "Kingdom Builds.com". The number is difficult but sounds like 4654 5805.


And I caught the same mention of Merv Starr at 4:37.


It was a difficult file to study. The level was way too high: Audacity tells me it had to be lowered by 7 dB just to prevent clipping. After adjusting the level I then had to adjist the equalization as it was very muffled/


Chuck




________________________________
From: IRCA <irca-bounces@xxxxxxxxxxxxxxxx> on behalf of Gary DeBock <d1028gary@xxxxxxxxxxx>
Sent: Monday, April 23, 2018 4:53 PM
To: America, Mailing
Subject: [IRCA] 918 kHz DU English Puzzle

In the same Cook Island 918 kHz MP3 as Cambodia and Shandong (recorded at 1658 UTC on April 12th) there are two DU English stations mixing at a strong level from 2:40 until 6:00 into the recording, one of which builds up strength until 4:36 with a strong "Midnight, with Merv (?) Starr" mention. Can anyone (Theo?) decipher the DU English to provide any identity clues? Thanks in advance!  https://dreamcrafts.box.com/s/takoyz5d3l19wockuky8x1e0d8m8fiv0


Gary DeBock (in Puyallup, WA, USA

..
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